# RO water vs tap (yes another post)



## jkan0228 (Feb 6, 2011)

RO water isn't really necessary unless youre keeping discus or sensitive shrimp and like to have as much control over the water parameters as possible.
Not sure if I can answer your question.


----------



## msawdey (Apr 6, 2009)

jkan0228 said:


> RO water isn't really necessary unless youre keeping discus or sensitive shrimp and like to have as much control over the water parameters as possible.
> Not sure if I can answer your question.


Im starting to think the same thing after using it now for so long. My original was that RO plus Equilibrium would be beneficial. But now Im starting to realize i could be using a neutral regulator with tap and probably get better results


----------



## Francis Xavier (Oct 8, 2008)

As for plants, I will never use non RO water again. Way too much crap in it that leads to random issues.

As for fish - what fish do you keep with RO? Generally mine have always been gorgeously healthy, but if you have a fish that prefers harder waters this is a different case.


----------



## Zefrik (Oct 23, 2011)

I agree with frank. I use rodi and my tanks are fine.


----------



## msawdey (Apr 6, 2009)

Angels and bolivian rams... The rams look the best I have ever seen them look, but the angels mostly dont look that healthy. 2 of them, fins are split and never seem to fully heal. I do 50% water changes every 2 weeks. run 2 eheim eccos and a uv sterilizer. Tank is right around 80 degrees

What do you guys use for additions to the ro/di? I just cant seem to figure out what is causing them to be stressed. I started thinking that it may be too many fish as i had 8 tetras in there with them, but the tetras left about 2 weeks ago to a local PlantedTank member

The Angels are my main concerns. Im going to trying a few things over the next few weeks such as adding neutral ph reg to allow for buffering and possibly reducing the amount of light on the tank (possibly too much causing stress) to see if their colors and fins repair.


----------



## DerekFF (May 24, 2011)

RO isnt needed except for some very specific conditions (breeding fish/shrimp, certain planted tanks) in general mostly everything we do doesnt need RO

Sent from my DROIDX using Tapatalk


----------



## wkndracer (Mar 14, 2009)

100% RO here with angels and plants being my focus.
Adding buffer with A&H baking soda but only to 2dKH.
Using GLA ultimate GH booster mixed to a range that varies from 3-5dGH.
Non injected and gassed tanks are all handled the same. pH ranges from 5.8 - 7pH depending.
No complaints on fish health.


----------



## msawdey (Apr 6, 2009)

DerekFF said:


> RO isnt needed except for some very specific conditions (breeding fish/shrimp, certain planted tanks) in general mostly everything we do doesnt need RO
> 
> Sent from my DROIDX using Tapatalk


hahaha and here starts the debate


----------



## msawdey (Apr 6, 2009)

wkndracer said:


> 100% RO here with angels and plants being my focus.
> Adding buffer with A&H baking soda but only to 2dKH.
> Using GLA ultimate GH booster mixed to a range that varies from 3-5dGH.
> Non injected and gassed tanks are all handled the same. pH ranges from 5.8 - 7pH depending.
> No complaints on fish health.


thats interesting i may give this a try also


----------



## wkndracer (Mar 14, 2009)

To increase KH using leveled spoons
Other brands I'm sure work but I've been loyal to Arm & Hammer
1/8 TSP : 6.6 gallons = 1dKH
1/4 TSP : 13.2gallons = 1dKH
1/2 TSP / 2.2grams : 26.4 gallons = 1dKH 
Using the digital scale 1level tsp varies 4.1 to 4.4 grams

HTH


----------



## msawdey (Apr 6, 2009)

wkndracer said:


> To increase KH using leveled spoons
> Other brands I'm sure work but I've been loyal to Arm & Hammer
> 1/8 TSP : 6.6 gallons = 1dKH
> 1/4 TSP : 13.2gallons = 1dKH
> ...


so in theory, wont the increase in KH actually help the pH swings?

also, how far does each pound of GLA booster get you?


----------



## DennisSingh (Nov 8, 2004)

I got a ro unit and now I swear by ro. I think its awesome for plants, discus and shrimp as long as u raise tds a lil. It doesn't take much, I don't think. But I've never been able to grow plants as well till now with ro.


----------



## wkndracer (Mar 14, 2009)

msawdey said:


> so in theory, wont the increase in KH actually help the pH swings?


absolutely it helps. 1.5 - 2dKH is enough buffer to keep things stable

edit; GLA is the same ratio as [email protected] 16g/20gal = 3dGH


----------



## msawdey (Apr 6, 2009)

wkndracer said:


> absolutely it helps. 1.5 - 2dKH is enough buffer to keep things stable
> 
> edit; GLA is the same ratio as [email protected] 16g/20gal = 3dGH


i was looking at the contents of equil.... there is quite a bit of other stuff in it like iron, magnesium, etc...

Whats the reasoning behind this?


----------



## happi (Dec 18, 2009)

IME, you will be lucky to have RO system, you will have access to many good looking plants, with hard water you wont able to. GH isn't the main problem, but KH plays an important role when we talk about hard water. 

MY water parameter are

GH 2-3dgh
KH 0dgh

TDS goes up due to fertilizers though


----------



## msawdey (Apr 6, 2009)

After reading these posts, Im becoming convinced once again RO is the way to go. What i think is message up, could be what I am using to mineralize and add a buffering capacity. Im going to try baking soda and GLA GH booster and see what happens


----------



## samamorgan (Dec 31, 2011)

msawdey said:


> hahaha and here starts the debate


There is no debate. His statement is completely true. Can it be beneficial? Sure. Is it a must have? No. Do the benefits of RO justify the cost(initial setup, chemical cost, storage space, time wasted, maintenance costs) in a non-sensitive setup? No. That isn't debatable.


----------



## msawdey (Apr 6, 2009)

samamorgan said:


> There is no debate. His statement is completely true. Can it be beneficial? Sure. Is it a must have? No. Do the benefits of RO justify the cost(initial setup, chemical cost, storage space, time wasted, maintenance costs) in a non-sensitive setup? No. That isn't debatable.


ha.. Hate to break it to you, but what you said is the debate. 

I live in San Diego, where we have some of the worst water in the country, so in my case, I always thought it was completely necessary


----------



## Francis Xavier (Oct 8, 2008)

samamorgan said:


> There is no debate. His statement is completely true. Can it be beneficial? Sure. Is it a must have? No. Do the benefits of RO justify the cost(initial setup, chemical cost, storage space, time wasted, maintenance costs) in a non-sensitive setup? No. That isn't debatable.


Sam, having lived in Seattle, RODI absolutely isn't worth it for you. The tap is nearly perfect there for planted tanks. 

Anywhere where you have hard water, such as Texas, it's not even worth it to do tap water because of all the issues that pop up that are completely avoidable. 

I have the unique perspective of having been around growing planted aquariums in different regions of the country with varying water qualities - those with water like in Seattle are extremely fortunate.


----------



## DerekFF (May 24, 2011)

msawdey said:


> ha.. Hate to break it to you, but what you said is the debate.
> 
> I live in San Diego, where we have some of the worst water in the country, so in my case, I always thought it was completely necessary


Its still not a debate. Its very simple, if you have super hard or just a bad water source then use RO. If you have good water then dont RO. Wheres the debate? Its a simple issue of how bad is your water, and if its bad, do you care enough to RO. There are a ton of plants who could care less if it was RO or or the ditch in front of your house

Sent from my DROIDX using Tapatalk


----------



## ray-the-pilot (Jul 5, 2011)

I don't think pure RO is a good idea. I don't even think trying to add hardness back into RO is a good idea because what you are adding is not the correct chemical balance that is found in normal water. 

I've been running an Amazon biotype for about 3 years and I need soft water about 70 ppm. My tap water is pretty hard at 350 ppm. I simply dilute my tap water 1/5 with RO to get the right level of Ca and Mg. I've tested my tap and the Ca/Mg ratio is good so I always have an infinite supply of ready made water. 

Unless your tap water is not potable, the Ca and Mg are in a better matrix then trying to build an artificial one. I've actually tried to build one and it is pretty much impossible.


----------



## fishyjoe24 (Dec 10, 2009)

http://www.plantedtank.net/forums/fertilizers-water-parameters/172243-ro-di-vs-tap-start-up.html


----------



## happi (Dec 18, 2009)

ray-the-pilot said:


> I don't think pure RO is a good idea. I don't even think trying to add hardness back into RO is a good idea because what you are adding is not the correct chemical balance that is found in normal water.
> 
> I've been running an Amazon biotype for about 3 years and I need soft water about 70 ppm. My tap water is pretty hard at 350 ppm. I simply dilute my tap water 1/5 with RO to get the right level of Ca and Mg. I've tested my tap and the Ca/Mg ratio is good so I always have an infinite supply of ready made water.
> 
> Unless your tap water is not potable, the Ca and Mg are in a better matrix then trying to build an artificial one. I've actually tried to build one and it is pretty much impossible.


all it takes is Ca and Mg sulfate to get both back in the ro water. again having complete control over the water paramter.


----------



## OverStocked (May 26, 2007)

msawdey said:


> Im starting to think the same thing after using it now for so long. My original was that RO plus Equilibrium would be beneficial. But now Im starting to realize i could be using a neutral regulator with tap and probably get better results


Neutral regulator is the spawn of Satan. Keep it away from planted tanks. 

If your water is more than "barely" hard, it will never do the job. 

no. no. no.


----------



## OverStocked (May 26, 2007)

samamorgan said:


> There is no debate. His statement is completely true. Can it be beneficial? Sure. Is it a must have? No. Do the benefits of RO justify the cost(initial setup, chemical cost, storage space, time wasted, maintenance costs) in a non-sensitive setup? No. That isn't debatable.


Awfully generalized, isn't that. 

My tap water has a TDS of nearly 400. I couldn't grow moss in it, before I used RO/DI mixed with tap(5% tap). 


There are plenty of people who have water that is literally unusable. On top of that, if you have a water softener and like some houses, no bypass for it, softened(sodium) water is horrible for plants and fish.


----------



## ray-the-pilot (Jul 5, 2011)

happi said:


> all it takes is Ca and Mg sulfate to get both back in the ro water. again having complete control over the water paramter.


Why are you putting all that extra sulfate in your water? "Real" water doesn't have much sulfate. The calcium and magnesium are as bicarbonates. The only place you can get calcium and magnesium bicarbonate is from your tap.

Also sulfates disrupt the Ca-Mg / KH ratio. Sulfate adds 2x KH compared to bicarbonate.


----------



## DerekFF (May 24, 2011)

OverStocked said:


> Awfully generalized, isn't that.
> 
> My tap water has a TDS of nearly 400. I couldn't grow moss in it, before I used RO/DI mixed with tap(5% tap).
> 
> ...


Use the hose in the front yard.....its pre-water softener. And its not a generalized statement. You either need RO as in your case or you dont. Anyone whos water is good from the tap doesnt "need" RO. If they do use RO its probably because somewhere on this forum someone told them that RO is better than tap and they took it to heart and now also reiterate that to others also, or they just want to be a mad scientist

Sent from my DROIDX using Tapatalk


----------



## OverStocked (May 26, 2007)

DerekFF said:


> Use the hose in the front yard.....its pre-water softener. And its not a generalized statement. You either need RO as in your case or you dont. Anyone whos water is good from the tap doesnt "need" RO. If they do use RO its probably because somewhere on this forum someone told them that RO is better than tap and they took it to heart and now also reiterate that to others also
> 
> Sent from my DROIDX using Tapatalk



But Sam said that it never justifies the cost and it isn't ever necessary. Keeping anything but african cichlids with my water would be a hard task. Keeping basic fish like hardy SA and CA cichlids has been difficult. I've tried to keep hundreds of species of fish over the years and prior to moving the tanks I keep and the maintenance clients I use to RO water, my life was a lot more complicated. 

I think that most of the people who say RO isn't ever needed are people who have never used them. Just like the people who say an Eheim is overrated. And that ADA soils are overpriced.

You can put together an RO system for about 90 bucks. I think I spent a thousand dollars on livestock before I learned that. 

Saying that you never need RO unless you keep the most sensitive of species is an over generalized statement. With my water, unless you want to keep common african cichlids you're SOL.


----------



## AaronT (Apr 11, 2004)

The answer is.... it depends.

In our old apartment we had well water. KH 1 GH 10 pH 6.7 out of the tap. I swear I could have bottled it and sold it to everyone on here if it didn't weigh so darn much. 

In our new place we have city water. I used to be able to grow plants really well then all of the sudden I had problem after problem. The new water here is KH 4-5 GH 20ish pH 7.8 + all the lovely "crap" as Frank put it that complicates things more.

The short of it is I now use a ratio of 2:1 RO to tap for water changes and my plants are MUCH healthier and so are my fish.


----------



## happi (Dec 18, 2009)

ray-the-pilot said:


> Why are you putting all that extra sulfate in your water? "Real" water doesn't have much sulfate. The calcium and magnesium are as bicarbonates. The only place you can get calcium and magnesium bicarbonate is from your tap.
> 
> Also sulfates disrupt the Ca-Mg / KH ratio. Sulfate adds 2x KH compared to bicarbonate.


can you prove this statement. why would people use sulfate if it mess up the Mg, Ca and KH. 

My Kh reads 0 even after adding sulfates.


----------



## msawdey (Apr 6, 2009)

I really think Aaron is completely right. 

I started testing my RO tank 3 times day. Before the lights, after the co2 has been on for 4 hours, and the end of the light cycle at hour 7 right after it turns off

Heres what my pH did: off- 6.9, after 4 hours- 6.3, end of light cycle 6.2

Now a pH swing from 6.9 to 6.2 is NOT NORMAL and probably does not happen in the wild.
RO water has no buffering capacity leading to the swing. This is exactly what started this whole thread, as my angels were becoming super stressed out

Yesterday, I changed out 20% of the water with tap. My ph on my tap is 8. I test the ph this morning, ph was 7.0, after 4 hours 6.9.. and im waiting to test tonight.

Ive read multiple posts on here that Co2 doesnt effect fish, but a full 1.0 ph swing has to be what was stressing them out. The fish look remarkably better today




AaronT said:


> The answer is.... it depends.
> 
> In our old apartment we had well water. KH 1 GH 10 pH 6.7 out of the tap. I swear I could have bottled it and sold it to everyone on here if it didn't weigh so darn much.
> 
> ...


----------



## triscene (Apr 7, 2012)

msawdey...looking forward to your test tonight. there is always good to add some portion of tap to increase KH as RO has it around 0.


----------



## AaronT (Apr 11, 2004)

msawdey said:


> I really think Aaron is completely right.
> 
> I started testing my RO tank 3 times day. Before the lights, after the co2 has been on for 4 hours, and the end of the light cycle at hour 7 right after it turns off
> 
> ...


I doubt I'm completely right, but I appreciate the sentiment. 

I should add that I run my CO2 24/7 with my soft water and have no issues. I run 1 bps into a reactor on an ADA 90-P. I don't test my pH. I swore off testing long ago.


----------



## slowgrower (Feb 7, 2012)

Sulfate adds nothing to KH. Alkalinity yes, KH no. 

pH swings are typical when you have a low KH. CO2 levels are buffered by bicarbonates and carbonates. I can't say for sure, but I would guess that if you tried testing your pH without running your CO2 you would find a smaller pH swing. Normally, pH is lowest in the morning caused by the respiration of both the plants and animals through the night and slowly begins to rise as photosynthesis kicks in. The fact that your pH is lowest at the end of the day suggests that the additional (artificial) addition of CO2 is what is lowering your pH. 

Have you tested KH?


----------



## msawdey (Apr 6, 2009)

Yes, i did test my KH. As with any RO water, the KH was almost nil. Yes, if I used something like sodium bicarbonate to raise the KH of the RO water, ok, works, but the whole thread was about me having issues with RO water while trying to keep things simple and simply not understanding the effect of CO2 on a tank with RO. I was using just equilibrium and neutral buffer which were not preventing the swings. 

While I agree there may be a slight pH swing depending the time of day and if the lights are on or off, my pH was jumping 1 full level. 7 down to almost 6 across the day. 

Arguing this is normal or healthy for fish who are sensitive just seems insane to me. This does not happen in the wild and I highly doubt they were bred in water like this

What I hope that those who are new to the hobby or inexperienced in RO water use like i am, get out of this, is an understanding that RO water needs a buffering capacity if used with a CO2 tank. Im figuring out there are a few simple ways of getting the buffering through bicarbonate or simply by mixing tap water with my RO 




slowgrower said:


> Sulfate adds nothing to KH. Alkalinity yes, KH no.
> 
> pH swings are typical when you have a low KH. CO2 levels are buffered by bicarbonates and carbonates. I can't say for sure, but I would guess that if you tried testing your pH without running your CO2 you would find a smaller pH swing. Normally, pH is lowest in the morning caused by the respiration of both the plants and animals through the night and slowly begins to rise as photosynthesis kicks in. The fact that your pH is lowest at the end of the day suggests that the additional (artificial) addition of CO2 is what is lowering your pH.
> 
> Have you tested KH?


----------



## happi (Dec 18, 2009)

how hard can this be, if you are worried about PH swings then try this.

use 100% RO water
use baking soda to raise the KH, use GH booster to raise the GH, how hard can this be, if you have KH of 0.5-1 then you should be fine, again IME i have had 0 KH in my tank and am keeping blue rams, havent lost any due to what we called PH swing. your problem must be somewhere else, maybe high/low water temp, ammonia, nitrate????

ammonia should not be a problem if your PH is low.


----------



## happi (Dec 18, 2009)

msawdey said:


> So I have been trying to figure out why my fish just arent looking that great.


what kind of fish is it? you said they don't look great, can you define that. maybe they need better food, water temp, water change, many things are possible here.


----------



## slowgrower (Feb 7, 2012)

msawdey said:


> Yes, i did test my KH. As with any RO water, the KH was almost nil. Yes, if I used something like sodium bicarbonate to raise the KH of the RO water, ok, works, but the whole thread was about me having issues with RO water while trying to keep things simple and simply not understanding the effect of CO2 on a tank with RO. I was using just equilibrium and neutral buffer which were not preventing the swings.
> 
> While I agree there may be a slight pH swing depending the time of day and if the lights are on or off, my pH was jumping 1 full level. 7 down to almost 6 across the day.
> 
> ...


The point I was trying to make is that I believe it is the CO2 you are injecting into the tank that is causing the pH swing. Without any buffering capacity (0 KH) the excess CO2 you are putting into the system is "unnaturally" lowering the pH. The CO2 system in water (total inorganic carbon) is comprised of all of the CO2, bicarbonate and carbonate. The ratio of each is controlled by the pH. More CO2 means lower pH. Having more buffer (bicarbonate and carbonate) in the water helps to lessen the effect of having more carbon dioxide because of more total carbon, thus a lower impact on the ratio of each.

I don't think anyone is arguing about anything. My point was that injecting CO2 into water is not "natural" and may be what is having the greatest impact on your pH, which is not directly related to the RO water but a byproduct of not having any buffering capacity. Again, I suggest testing your pH over the course of a day without your CO2 running and see what the results are. If the pH swing isn't as abrupt you could assume that adding a little buffer (KH not GH) would help while injecting CO2.

I agree that a mix of RO/tap water could solve the problem but don't be misled, there are plenty of products out there that are capable of doing the same. In my opinion, if you're going to go through the trouble and cost to produce RO water, adding tap water doesn't always make sense. I'm not saying don't do it, I'm just saying there are relatively simple ways to get the water that you want.

Hope this is helpful and not as confusing as I think I'm making it sound.:icon_wink


----------



## triscene (Apr 7, 2012)

is there any rule of mixing ro and tap in order to get some desired number? Similar as it is with tds or gh values. Having tds of 185 but having ph above 7.3..curious how to mix to get tds of around 120 and ph around 6.5. My ro has around 5.5 and tds 0. Anyone who would help to reach my goal? If possible by mixing ro and tap...i try to avoid magic drops


----------



## msawdey (Apr 6, 2009)

I was mostly agreeing with you. The clear mistake here was using RO without any buffering capacity. I've been on this forum for about 2-3 years now and have read countless times, just use equilibrium with RO and you'll be fine. Clearly, as we haven established, that's not true. I guess this thread is for those who are newer to the trade on what to do and what not to do.

RO is definitely beneficial, but this mistake probably has cost me well over 100$ in fish over the last 6 months. 

So the take home message, if your going to use RO, use baking soda to boost the buffering capacity or mix it with tap (reason i said tap was you already have buffering + hardness)



slowgrower said:


> The point I was trying to make is that I believe it is the CO2 you are injecting into the tank that is causing the pH swing. Without any buffering capacity (0 KH) the excess CO2 you are putting into the system is "unnaturally" lowering the pH. The CO2 system in water (total inorganic carbon) is comprised of all of the CO2, bicarbonate and carbonate. The ratio of each is controlled by the pH. More CO2 means lower pH. Having more buffer (bicarbonate and carbonate) in the water helps to lessen the effect of having more carbon dioxide because of more total carbon, thus a lower impact on the ratio of each.
> 
> I don't think anyone is arguing about anything. My point was that injecting CO2 into water is not "natural" and may be what is having the greatest impact on your pH, which is not directly related to the RO water but a byproduct of not having any buffering capacity. Again, I suggest testing your pH over the course of a day without your CO2 running and see what the results are. If the pH swing isn't as abrupt you could assume that adding a little buffer (KH not GH) would help while injecting CO2.
> 
> ...


----------



## msawdey (Apr 6, 2009)

happi said:


> what kind of fish is it? you said they don't look great, can you define that. maybe they need better food, water temp, water change, many things are possible here.


Blue Angels, temp is 81 degrees, water changes are 50% every 2 weeks, test nitrates even at 2 weeks 0ppm. I feed bloodworms and new life spectrum pellets. I have more than enough filtration as its a 55 with 2 eheim eccos 2234s with a UV filter..

To say the least, over the last 6 months.. i narrowed it down to the pH swings through testing


----------



## ray-the-pilot (Jul 5, 2011)

happi said:


> can you prove this statement. why would people use sulfate if it mess up the Mg, Ca and KH.
> 
> My Kh reads 0 even after adding sulfates.


My mistake. CaSO4 reduces KH slightly (was thinking of Carbonates) People use sulfates because the cannot buy CaHCO3. (It only comes from naturally hard water). They would like to use CaCO3 but it is amost insouble in water. You could make CaHCO3 by placing CaCO3 in some distilled water and let it adsorb CO2 from the atmosphere for a long time to get it to dissolve, but then you would have tap water.


----------



## AaronT (Apr 11, 2004)

It should be noted that the lower your KH is, the less CO2 you'll need to inject as it more readily dissolves into softer water. I run my CO2 24/7 at 1 bps on an ADA 90-P (50 gallon breeder) size tank. This is more than enough CO2 and running it 24/7 seems to help with the swings. 

So long as there are no other acid buffers in the tank CO2 itself can't push the pH below about 5.5. That's low for sure, but nothing tetras, rams, rasboras, etc... aren't used to.

Another easy option for those with super hard water such as in Texas and Florida is to use an RO unit with 100 gpd membranes. The 100 gpd membranes have a lower rejection rate, something like 90%. So if your GH is crazy high out of the tap, 10% of that should be just right, especially after a month or so of use when it's not running at full efficiency.


----------



## ray-the-pilot (Jul 5, 2011)

happi said:


> how hard can this be, if you are worried about PH swings then try this.
> 
> use 100% RO water
> use baking soda to raise the KH, use GH booster to raise the GH, how hard can this be, if you have KH of 0.5-1 then you should be fine, again IME i have had 0 KH in my tank and am keeping blue rams, havent lost any due to what we called PH swing. your problem must be somewhere else, maybe high/low water temp, ammonia, nitrate????
> ...


 How do you measure KH? If your KH were really 0 then your tank pH would be 4.3. That seems low. The formula that you propose would have the right kH and GH but it would have way more NaSO4 than would be found in natural water. Do you have a CO2 controller on your tank?


----------



## ray-the-pilot (Jul 5, 2011)

slowgrower said:


> Sulfate adds nothing to KH. Alkalinity yes, KH no.


This is a commonly confused issue KH vs total alkalinity. If you are talking about the carbonate buffer system only, then they are the same thing. So any acid will decrease KH and any base will increase KH. Adding an acid sulfate (NaHSO4) decreases KH and buffering capacity. Adding a base (NaOH) increases KH and buffering capacity.


----------



## triscene (Apr 7, 2012)

my RO has pH 6.5
when adding ratio 3:1 (RO:tap) i get around 7,5 pH
i set up this ratio to have my GH around 5 (tap 12-13, RO 0), TDS is around 72ppm

how to reach pH around my pure RO without adding any other "special" drops, peat, driftwood etc...just combining my tap and RO.
i am keeping CRS SS+ grades and i also need lower pH but GH around 3-5, not having issues with molting.
thanks

Edit: i just found this link:
http://www.theplantedtank.co.uk/RO.htm

what would be effect on pH, any or none?


----------



## AaronT (Apr 11, 2004)

I've been thinking about this some more and I really think it's best to use some sort of filtration on water change water, even if it's not RO. Hardness really only becomes an issue when it pushes the pH to be above neutral, which IMO is not ideal for most freshwater plants. 

So, if your water is city water and is fairly soft, but you still have lots of issues consider setting up a 3 stage filter without the RO part. So it would go micron filter, carbon filter, smaller micron carbon filter. Such a setup would be less than $100.00 and replacement filters are only about $10-$20 every six months. It's well worth the investment to have good clean water without all the added chemicals.

IMO this filtered water is better than simply treating with a chlorine / chloramine remover such as seachem prime. I'm not knocking prime by any means, it's a nice product, I just think using the filter system is the better, perhaps cheaper alternative to clean water changes.


----------



## happi (Dec 18, 2009)

ray-the-pilot said:


> How do you measure KH? If your KH were really 0 then your tank pH would be 4.3. That seems low. The formula that you propose would have the right kH and GH but it would have way more NaSO4 than would be found in natural water. Do you have a CO2 controller on your tank?


KH from RO is 0, GH is also 0. the PH reads 6.2, i dont know how you are getting the PH of 4.3????


----------



## somewhatshocked (Aug 8, 2011)

Sorry, this is just conjecture. Nothing personal but what works for you may not work for someone else and you illustrate that in this comment. There is very little that's set in stone in aquaria. 

Your tap water mixed with RO works for you. Their tap water may not work for them in any circumstance.

To suggest that adding "hardness" back to RO isn't a good idea because you can't reach the "correct chemical balance that is found in normal water" is… not good advice, to say the least. Primarily because next to no water source is the same and years upon years of experience with thousands (millions?) of hobbyists seem to prove otherwise.

If reconstituting/remineralizing RO wasn't a good idea, I wouldn't have been able to maintain reef tanks for a decade and a half and I wouldn't be able to keep super-demanding dwarf shrimp with ease. 

I'm glad this thread - and many others like it - are here to show that it's up to the needs of you and your livestock when it comes to whether or not you want to use RO/DI water or tap. Or, in my case, I like the stability and reliability of making my own water so I don't have to worry about whatever junk the water company decides to add to the public supply at a moment's notice. That way I don't have to complain when the water company kills all my livestock or causes something janky with my plants. 

The world is a better place when I'm not complaining. :drool:



ray-the-pilot said:


> I don't think pure RO is a good idea. I don't even think trying to add hardness back into RO is a good idea because what you are adding is not the correct chemical balance that is found in normal water.
> 
> I've been running an Amazon biotype for about 3 years and I need soft water about 70 ppm. My tap water is pretty hard at 350 ppm. I simply dilute my tap water 1/5 with RO to get the right level of Ca and Mg. I've tested my tap and the Ca/Mg ratio is good so I always have an infinite supply of ready made water.
> 
> Unless your tap water is not potable, the Ca and Mg are in a better matrix then trying to build an artificial one. I've actually tried to build one and it is pretty much impossible.


----------



## triscene (Apr 7, 2012)

how about adding CaCo3 and MgSo4 to increase gh? Would it be enough? Keeping higher grade CRS.


----------



## ray-the-pilot (Jul 5, 2011)

happi said:


> KH from RO is 0, GH is also 0. the PH reads 6.2, i dont know how you are getting the PH of 4.3????


 That is the pH of unbuffered water when CO2 dissolves in it. It may come out of the RO at 6.2 but when in contact with air it changes to 4.3. I've tested a lot of water and that is what happens.


----------



## ray-the-pilot (Jul 5, 2011)

triscene said:


> how about adding CaCo3 and MgSo4 to increase gh? Would it be enough? Keeping higher grade CRS.


 Did you ever try this? What happened? I'm interested.


----------



## triscene (Apr 7, 2012)

ray-the-pilot said:


> Did you ever try this? What happened? I'm interested.


i havent, just got recommendation as Ca and Mg would be covered, question is whether it would be enough for successful molting 

just realized and upset due to finding that Ultra version is just 100ml version in 250ml bottle to be diluted with RO..hm


----------



## slowgrower (Feb 7, 2012)

This is a theoretical value. In an open system, like an aquarium, CO2 tends to equilibrate with the atmospheric concentration. Even with zero buffering one would need to be constantly injecting CO2 to maintain such a low pH.



ray-the-pilot said:


> That is the pH of unbuffered water when CO2 dissolves in it. It may come out of the RO at 6.2 but when in contact with air it changes to 4.3. I've tested a lot of water and that is what happens.


----------



## happi (Dec 18, 2009)

ray-the-pilot said:


> That is the pH of unbuffered water when CO2 dissolves in it. It may come out of the RO at 6.2 but when in contact with air it changes to 4.3. I've tested a lot of water and that is what happens.


if that is the case then i should have dead fishes during water changes, i change my water soon as i get home from work during the water change day. during this time co2 is still on and lights are still on, they were about to go off in another hour or so, i started to change the water during this time. in this case am adding 6.2PH (i do big water changes 70%) water into my tank water which should have very low PH. then how come i don't see any fish being shock from the sudden change in PH?


----------



## somewhatshocked (Aug 8, 2011)

If that's the case… why is it I set up a bucket of RO/DI water last night along with an air stone and the pH is still basically the same? (Also tested an open jug of RO/DI water that's been sitting by my tanks for at least a week - same pH)

slowgrower has it right. 

I'm doubting you've tested a lot of water and come up with those alleged results unless you've done so in super-scientific clean rooms with sealed, air-tight containers, specific concentrations of CO2, yadda yadda.



ray-the-pilot said:


> That is the pH of unbuffered water when CO2 dissolves in it. It may come out of the RO at 6.2 but when in contact with air it changes to 4.3. I've tested a lot of water and that is what happens.


----------



## ray-the-pilot (Jul 5, 2011)

somewhatshocked said:


> If that's the case… why is it I set up a bucket of RO/DI water last night along with an air stone and the pH is still basically the same? (Also tested an open jug of RO/DI water that's been sitting by my tanks for at least a week - same pH)


This is curious? what pH meter did you use? How did you calibrate it? I'm using a Hach Sension3 that has a read out to 3 decimal places and calibrated with NIS traceable standards. I do make lots of mistakes. Why don't you PM me and we can work out what the difference is between what you are doing and what I am doing.


----------



## ray-the-pilot (Jul 5, 2011)

slowgrower said:


> This is a theoretical value. In an open system, like an aquarium, CO2 tends to equilibrate with the atmospheric concentration. Even with zero buffering one would need to be constantly injecting CO2 to maintain such a low pH.


No I think you miss the point. The KH of RO water is not 0 but something above 0 but not measurable by the test being used. 

Real 0 KH water will absorb very small amounts of CO2 from the atmosphere and because it has no buffering capacity will go to pH 4.3


----------



## slowgrower (Feb 7, 2012)

ray-the-pilot said:


> This is a commonly confused issue KH vs total alkalinity. If you are talking about the carbonate buffer system only, then they are the same thing. So any acid will decrease KH and any base will increase KH. Adding an acid sulfate (NaHSO4) decreases KH and buffering capacity. Adding a base (NaOH) increases KH and buffering capacity.





ray-the-pilot said:


> No I think you miss the point. The KH of RO water is not 0 but something above 0 but not measurable by the test being used.
> 
> Real 0 KH water will absorb very small amounts of CO2 from the atmosphere and because it has no buffering capacity will go to pH 4.3


Apparently I'm confused and I'm missing the point? Ray, I'm sorry, but I feel like you are spreading misinformation.

By definition, carbonate hardness (KH) and total alkalinity (TA) are not the same thing. Acids don't lower KH, they lower pH, and adding NaOH does not increase KH, but it does increase alkalinity.

http://en.wikipedia.org/wiki/KH_(hardness)

http://en.wikipedia.org/wiki/Alkalinity

Moving on, even distilled water, millepore or double DI will not absorb enough CO2 from the atmosphere to cause the pH to go to 4.3 as Somewhatshocked clearly pointed out. Even if one were to inject CO2 into the water, disequilibrium with the atmosphere would cause it to come out of solution. The only way you could maintain a pH of 4.3 would be in a closed system. Try it and let us know what you find out.


----------



## plantbrain (Dec 15, 2003)

A strong acid will destroy KH..........eg H2SO4, HNO3, even acetic acid, eg distilled vinegar ........

CO2 is an acid but will not destroy KH for example.

The issue perhaps with some pH measures is calibration and perhaps the RO/DI filter itself, old membranes, by pass, flow rates, basically purity, 5.0ppm of alk will make a significant difference in the end points.

A TDS/Conductivity meter would resolve this and is often how changes and issues with RO is needed. This may be easier to tell differences between RO water smaples than say a Lamotte or Hach alkalinity test kit.

If you do not need to monkey with the KH, then don't for the plants/fish.
It's a headache, but a reservoir and pump system can make it much much easier if you need to go that route.

We added a 700 Gallon RO reservoir for a client and 1000gpd Stainless steel RO system. LA water, nasty sludge, then a house carbon filter.


----------



## plantbrain (Dec 15, 2003)

slowgrower said:


> , and adding NaOH does not increase KH, but it does increase alkalinity.


This is a common issue for water treatment where they do lime softening and some other processes. This is called hydroxide alkalinity, it's a PITA.

I'm not sure about how much of this causes issues for folks using the pH/Kh chart for CO2 measurements. Not much I would say.

Tannins and peat? This can be measured.
Poly phosphates? Yea, this can cause some issues.
Marine systems also have borate alkalinity

Quite a few folks with moderate to hard tap water, may have the hydroxide issue making them think they have more CO2 in the water than they think. MatPat recalled when I was in Ohio and he had 220ppm according to the chart, but had nice fish and plants. 

pH meter was a Pinpoint and fresh probe, calibrated. 

We knew something was wrong.

Likely the high pH they use to remove/precipitate CaCO3 with partial lime softening.
pH's are raised to about 10.1 or so.........they sometimes add CO2 to lower the pH back down, recarbonation of the water. 

They typically blend the treated water with the regular water for a "blend" mix of super soft with the hard tap, just like we do with RO and tap. This can change depending and alter the make up.

While everyone likes to say there's so much we do not know, or how every tank is different or there are many ways to skin a kitten.........especially the cute cuddly ones..........such statements offer little information, we learn little from that. However, with tap water, it's treatment and sources can vary by vast amounts location to location.

Why we have non carbonate alkalinity is an interesting topic but it's not measured much at all in planted tanks.


----------



## slowgrower (Feb 7, 2012)

plantbrain said:


> A strong acid will destroy KH..........eg H2SO4, HNO3, even acetic acid, eg distilled vinegar ........
> 
> CO2 is an acid but will not destroy KH for example.


This is a valid point but I doubt anyone is adding sulfuric or nitric acid to their tanks...at least I hope not. But yes, a STRONG acid would consume all of the buffering potential, effectively "destroying" all of the carbonate alkalinity.



plantbrain said:


> This is a common issue for water treatment where they do lime softening and some other processes. This is called hydroxide alkalinity, it's a PITA.
> 
> I'm not sure about how much of this causes issues for folks using the pH/Kh chart for CO2 measurements. Not much I would say.
> 
> ...


I agree that hydroxide alkalinity typically isn't a concern for aquarists, I was simply pointing out that adding NaOH will not increase KH, as ray-the-pilot claimed.



plantbrain said:


> If you do not need to monkey with the KH, then don't for the plants/fish.
> It's a headache, but a reservoir and pump system can make it much much easier if you need to go that route.


Kind of surprised to hear you say this. If we go back to the issue the original poster (msawdey) was having, it was most likely a low KH (from RO water) and the addition of CO2 that was causing swings in pH. Most folks using RO/DI will need to "monkey" with KH. Care to elaborate?


----------



## jgb77 (Dec 13, 2006)

What is the issue with having the ph swing from co2 injection? In my experience, the fish I've kept did not care if the ph moves 1 plus degree from co2. As long as the kh stayed the same, the fish seem unaffected.
I also wanted to add that I use a lot of surface agitation, so there should be more oxygen for the fish so that makes a difference I'm sure.
John


----------



## plantbrain (Dec 15, 2003)

slowgrower said:


> Kind of surprised to hear you say this. If we go back to the issue the original poster (msawdey) was having, it was most likely a low KH (from RO water) and the addition of CO2 that was causing swings in pH. Most folks using RO/DI will need to "monkey" with KH. Care to elaborate?


No, they do not. This is something I've questions for decades now.
Something that has been woven into the myths of the planted aquarium using CO2.

Mostly because of the web and poor understanding of alkalinity, CO2 enrichment and pH affects using CO2 vs say baking soda etc.

As stated by others, the pH crash, pH drop due to CO2 as some problem or lethal issue for fish, plants, shrimp etc........is manure.

I have very low KH tap, and have clients that add only RO, all of SF has low KH and the club here is quite large. Some use to add a little baking soda back 10-15 years, but few if anyone in the club does today. There's just no need.

As long as you have some KH for measurement purposes if you use the pH/KH table....that would be about it.

A simple method to measure CO2 where KH is absent/immeasurable as far as a hobbyists is concerned:

Add say 1 degree of KH with baking soda after a water change. Take the pH/Kh reading, hope there is no other forms of alkalinity/be aware that may be the case.

Then for the next water changes, do not add baking soda back. This was done many many many times with no adverse effect on fish, plants etc. 
Not by just me, but by many folks.

The CO2 dosing rate/bubble supply was kept the SAME and is the same after you remove the alkalinity, you just have a lot more trouble measuring CO2 this way without the Alkalinity, but it should be the same/same CO2 available to the plants. 

This is one of things where folks propose a hypothesis and then the hobbyists test it and sees if the hypothesis can be falsified. In this case, I've found no evidence that supports low to absent KH/alkalinity is detrimental to a planted tank, livestock, plants. In other words, it was falsified.

If the user does not know how to dose CO2 correctly and they gas their fish, which we see some newbie doing this very week on these forums, this is easy to see why they blame pH crash etc, and not just the CO2 poor management on the issue. :icon_idea

A good myth is very hard to kill.


----------



## slowgrower (Feb 7, 2012)

jgb77 said:


> What is the issue with having the ph swing from co2 injection? In my experience, the fish I've kept did not care if the ph moves 1 plus degree from co2. As long as the kh stayed the same, the fish seem unaffected.
> I also wanted to add that I use a lot of surface agitation, so there should be more oxygen for the fish so that makes a difference I'm sure.
> John





plantbrain said:


> No, they do not. This is something I've questions for decades now.
> Something that has been woven into the myths of the planted aquarium using CO2.
> 
> Mostly because of the web and poor understanding of alkalinity, CO2 enrichment and pH affects using CO2 vs say baking soda etc.
> ...



I'm not sure that there is. It was the concern of the original poster.





plantbrain said:


> I have very low KH tap, and have clients that add only RO, all of SF has low KH and the club here is quite large. Some use to add a little baking soda back 10-15 years, but few if anyone in the club does today. There's just no need.
> 
> As long as you have some KH for measurement purposes if you use the pH/KH table....that would be about it.
> 
> ...


This sort of makes sense, but its difficult to follow without actual numbers. While the amount of CO2 available would be the same, removal of the alkalinity would mean the pH should be lower. At low KH, pH is also quite low (6.0) before you start getting into the ideal CO2 range. I would however point out that if an aquarium has a tendency to stabilize at a pH of say 6.6, it might make sense to keep KH slightly higher to keep both the CO2 at ideal concentration without the pH dropping as much, although as was pointed out "pH drop due to CO2 as some problem or lethal issue for fish, plants, shrimp etc........is manure."




msawdey said:


> I really think Aaron is completely right.
> 
> I started testing my RO tank 3 times day. Before the lights, after the co2 has been on for 4 hours, and the end of the light cycle at hour 7 right after it turns off
> 
> ...


If we use the original posters water parameters, we see that his pH started at 6.9 and ended at 6.2. Assuming that their KH was negligible, as previously stated, and using the KH/pH chart, they most likely did not gas their fish. However, by adding 2 degrees KH it would be possible for CO2 to be at an "ideal" concentration at a pH of around 6.6.

I am curious about one thing, and perhaps someone knows the answer; what is actually being measured by the KH test kits most of us hobbyists use? Is it truly carbonate hardness or is it in reality total alkalinity? The reason I ask is that I wonder if having elevated concentrations of nutrients could have an impact on the buffering we see in our aquariums since both nitrate and phosphate contribute to total alkalinity.


----------



## plantbrain (Dec 15, 2003)

Well, here's some evidence:

Shrimp, higher grade CRS's, Fire shrimp/RCS, fish, cichlids etc, all breeding........with at least 1 full unit of change daily.



































These discus breed as well as the angels with daily 1-.2 pH changes:








These are all F1 Anegls in this tank, they have never know any other aquarium:









If the fish are reproducing and being subjected to large pH changes with low alkalinity...........from CO2............ why is that? Perhaps there is more to health of the fish than mere CO2 ppm, since respiration is the exchange of BOTH O2 and CO2............. it may be wiser to look at O2 and CO2 measure than pH.

Perhaps lower O2, less healthy plant biomass, poorer filtration etc...........there are a few things we can rule out and compare.........but many things we cannot.

CO2 mismanagement can cause issues, poor measurement and gassing fish are VERY common on these forums, I see one about every week where someone gasses their fish and adding baking soda is suggested very often to stabilize pH. Then they still gas their fish:icon_redf Plenty of ways to cause issues, but we can focus on one, isolate and look at that closely.


----------



## plantbrain (Dec 15, 2003)

CRS's:


----------



## msawdey (Apr 6, 2009)

Tom,

In the case of the angels and the discus in the big tank... was their ANY KH to start with in the water? Something that could buffer a pH swing? As someone who isnt as knowledgeable as you are and only keeps a single 50 gallon tank and was only using RO, could it be that the pH swing in my 50 gallon tank could affect my fish at a greater degree than a tank that is much larger?

I still do believe that the pH swings were causing issues with my Angels. I am putting half RO and Half tap in with 50% water changes once every 2 weeks. Since this original post, the angels look much healthier, their colorations are vibrates, and even my bolivian rams are finally colored out.


----------



## plantbrain (Dec 15, 2003)

Well larger tanks will have more stability, but the focus is more on just having low KH, not even worrying about it............and focusing on plant growth, high O2, and then CO2 to the point just below where it effects fish behavior. these tanks have excellent care, good large frequent water changes, excellent plant health and high plant density.

Fish are also well feed.

Tap waters can have many things added to it.
A carbon whole house filter sometimes can get rid of unknowns for using tap water. If you use RO water............those chemicals are removed anyway.
But make sure to replace the membrane and the pre filters on the RO unit often.

I took a reading a few days about, I had a drop of from 6.8 to 5.3. 
O2 was 7.8 to about 11.3 over 24 hours.

I do not think you gain much by adding more than say 10-20ppm of KH.
Doing so will NOT harm your fish/pants/tank etc.............but running at zero or near zero does not seem to cause issues either. the pH drop has absolute no merit with respect to CO2 enrichment.

Here's the nail in the coffin: large water changes while the tank is enriched with CO2, the pH drop occurs in a a few minutes upon refilling the tank with tap water(pH around 7.8, tank about mid to high 5's). No fish has ever showed any signs of stress or illness, I do this weekly and have......for 2 decades with tap water from all over CA, FL etc. I almost always do water changes in the morning and after the lights/CO2 have been on for 1-2 hours.
Tank in the evening is pearling like mad.

Never had an issue due to pH itself, only CO2 if you add too much.
There's a big difference and you(or anyone with a pH meter) can do the large water change test to see. also, make sure there is no stray current affecting the pH meter, take a water sample in a cup from the tank, it should match or be very.....close to the tank's pH, it the tank is lower by much, then you have stray current.

I had nasty tap and did the 50/50 split blend etc............I did not need to do more RO, which is a PITA if you lack storage, so a 5 gal bucket of RO+ 5 Gal of Tap= 20 gal tank, weekly 50% was easy.
If the 50/50 works and you need less RO, do it!!! Anything to reduce or ween off the RO is a good idea.


----------



## aquatic serenity (May 24, 2011)

Instead of R/o which strips out some beneficial minerals...you can use either of these 2 filters..I have used both with great results..The crystal quest is preferred when there is high nitrate present in the tap water...I have toured the facility where the KOLD STERIL is made..

http://crystalquest.com/Qstore/Qstore.cgi?CMD=011&PROD=1174602528&ADMIN=YES


http://www.marinedepot.com/reverse-osmosis-deionization_kold_ster-il-ap.html


----------



## jgb77 (Dec 13, 2006)

I believe Aaron had the same suggestion earlier:


AaronT said:


> So, if your water is city water and is fairly soft, but you still have lots of issues consider setting up a 3 stage filter without the RO part. So it would go micron filter, carbon filter, smaller micron carbon filter. Such a setup would be less than $100.00 and replacement filters are only about $10-$20 every six months. It's well worth the investment to have good clean water without all the added chemicals.
> 
> IMO this filtered water is better than simply treating with a chlorine / chloramine remover such as seachem prime. I'm not knocking prime by any means, it's a nice product, I just think using the filter system is the better, perhaps cheaper alternative to clean water changes.


----------



## 150EH (Dec 6, 2004)

I haven't started using my unit yet but I plan on mixing my RO/DI water with my tap water to get it close enough without using any Equilibrium, etc. I use a software program (Aquarix) that will help me figure out how much RO and how much tap will get me close the the kH and gH I want, then I may have to add some gH booster, etc but I'm not sure at this point. I will try to use the least amount of RO possible but I still need a better quality of water than our well can produce on it's own.

I know there are a lot of little things I need to learn about RO, like to run the unit for 10 minutes before I let the water enter the RO membrane to get rid of the fines in new filters, I've also read if your unit does not run everyday you should also run the unit 2 minutes or so before letting water pass through the RO membrane as TDS readings maybe near 100 and drop to 2 after a couple minutes, this helps the membrane last longer and keeps poor quality water out of your tank. I've read so many tips and tricks I'm not sure I can keep track of it all but these 2 seem logical and I've heard a lot of folks ask why their TDS meter is showing these numbers.


----------



## msawdey (Apr 6, 2009)

I bow all mighty planted tank master... this is exactly what i needed to hear.. thanks for reaffirming it :biggrin:



plantbrain said:


> Well larger tanks will have more stability, but the focus is more on just having low KH, not even worrying about it............and focusing on plant growth, high O2, and then CO2 to the point just below where it effects fish behavior. these tanks have excellent care, good large frequent water changes, excellent plant health and high plant density.
> 
> Fish are also well feed.
> 
> ...


----------

