# Using RO DI water



## larusaquarium (Feb 21, 2015)

I bought a RO DI system last night and I keep discus in my 55 gallon heavily planted tank. 
My question is, to make RO water safe what do I need to add to it?
I'm planning on using Seachem Equilibrium. Do I also need to add alkaline buffer and acid buffer? 


Thanks


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## larusaquarium (Feb 21, 2015)

*Preparing RO DI water for planted tank*

Before anyone go bananas and get all worked up and say no to RO water in planted tank here's my situation. Municipal water I get is literally liquid rock. Water even has a strong smell of ammonia/suffer like seachem prime. And water contains so much silicates and phosphates I be battling diatoms in my tank for nearly a year. 
I have a heavily planted 55 gallon discus tank. 
I'm planning on using seachem equilibrium in my RO water. Question is, is that all I need to add?
Or
Do I need to add acid buffers and alkaline buffers as well?

(My ro di unit produces 7.0 ph and I don't mind keeping that ph level. What I'm worried about is KH and GH. Cas they both gonna be 0 once the water passes through DI process)


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## All4Fish (Jun 23, 2014)

I adjust my RO water to match my tank parameters (for water changes, not top off) using baking soda (for kh) and equilibrium (for gh). Baking soda will raise the pH so test and experiment to get what you need. 
I found that adding buffers is a slippery slope as they don't stay stable. I also use Prime to be sure there is no chlorine/chloramine. Not sure it is necessary, but don't want to risk it.

PS - saw your other post; I have an 80 gallon planted tank and it does fine with RO!


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## larusaquarium (Feb 21, 2015)

RO DI water contains no chlorine, therefor no need to add prime or and water conditioners. When you add prime to RO water it messes up the PH levels, lol. 
My question is not about using prime or water conditioners. My question is, do I need to add anything other than seachem equilibrium?


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## Linwood (Jun 19, 2014)

Equilibrium is primarily aimed at raising dGH, though I suspect you get a slight dKH from it as well. When I mix mine, I add baking soda to get dKH of about 4, which gives about 7.6-7.8 ph. Add less the ph is lower, so it depends on where you want to land. I think I would add at least a tiny amount just to get some stability in ph swings.

Equilibrium and baking soda are all I add other than fertilizers.


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## Linwood (Jun 19, 2014)

larusaquarium said:


> (My ro di unit produces 7.0 ph and I don't mind keeping that ph level. What I'm worried about is KH and GH. Cas they both gonna be 0 once the water passes through DI process)


Well, actually it doesn't. Or it is not that simple -- the ph it produces (or more precisely of distilled water) depends on temperature and aeration, and could be significantly lower or slightly higher as well.

I have lousy tap water as well, and mix my own RODI water. I mix it up for dKH=4 and dGH=6 (I usually land a bit higher on both for reasons somewhat mysterious but not relevant). That gives me about 7.8ph in a non-CO2 tank after aeration. Drop the baking soda amount and the ph would drop as well, drop it too much and it is more prone to swings in PH (e.g. to the natural nitrification process that will make it more acidic over time). 

I think you'll find it easier to keep stable slightly alkaline, at least I do, but I would recommend at least a bit of baking soda with the Equilibrium regardless. Some sodium is needed for the good bacteria (or so I've read) and not sure if any is in the equilibrium.


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## larusaquarium (Feb 21, 2015)

I'm getting more confused with the answers.


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## larusaquarium (Feb 21, 2015)

All these extra info is confusing me. 
I hope seachem reply to the email I sent them regarding this. 
I don't feel adding baking soda in to my tank since baking soda is not designed to be used in aquariums. 
All I want to know is as a newbie for RO system, and assuming all I have is equilibrium to add is that gonna be enough?


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## Linwood (Jun 19, 2014)

larusaquarium said:


> I'm getting more confused with the answers.


I'm sorry, can you elaborate on the confusion? 

Simple RODI water solution: 

- 20 Gallons RODI water
- 2 Tablespoons or about 32 grams equilibrium
- 1 teaspoon (about 5 grams) sodium bicarbonate (baking soda, or Seachem Alkaline buffer - same stuff)

This gives you about dGH=6 and dKH=2. I'm not sure exactly where the PH will land, but at 78F my guess is about 7.2 to 7.4.

Here's a PH charge for injected CO2. I can't find a more detailed one for non-injected that include temperature.

http://www.plantedtank.net/forums/showthread.php?t=23531

Non-injected CO2 takes will run about 3ppm of CO2 with reasonable aeration, so if you look on the dKH=2 side you'll see that is between 7.2 and 7.4.
In fact if you follow that diagonal you'll see it ranges from maybe 6.7 with negligable dKH to ph=8 for dKH=10. 

Basically you control resulting ph by how much baking soda you have.

And not shown -- the less you have, the more affect small chemistry events in your tank will affect ph. 

If you want really soft general hardness as well, say dGH=2 instead of 6, just divide the Equilibrium by 3 above.


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## natebuchholz (Sep 28, 2013)

The problem is the stability of the parameters through your KH. If this value is too low (below 4dkh) you may experience dramatic shifts in your water parameters and this can be very stressful/lethal to most inhabitants.


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## Linwood (Jun 19, 2014)

larusaquarium said:


> All these extra info is confusing me.
> I hope seachem reply to the email I sent them regarding this.
> I don't feel adding baking soda in to my tank since baking soda is not designed to be used in aquariums.
> All I want to know is as a newbie for RO system, and assuming all I have is equilibrium to add is that gonna be enough?


You have two threads going, I just posted a simple formula in another thread.

"Baking soda is not designed to be used in aquarium"... sorry, but that's a silly statement. Baking Soda is a commercial form of sodium bicarbonate. Various carbonates are found in rocks and soil and are dissolved in every fresh water lake or pond you will ever find, in various amounts.

But you can also buy Seachem Alkaline Buffer, which is clearly designed for aquariums, if that adds to your comfort by all means -- it's good stuff, nothing at all wrong with it.

When you remove EVERYTHING from water, you have to add chemicals back in. That's just how it goes. Someone here (Joe, I'm channeling you if you are around) told me once: 

"The great thing about RODI water is you are in complete control of your water. 

The bad thing about RODI water is you are in complete control of your water."​
:wink:


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## FreshPuff (Oct 31, 2011)

I would recommend only using Seachem Equilibrium. Your PH is fine and I wouldn't worry about KH measuring 0. It is much easier to keep your water parameters stable this way.

I hope this answers your question.


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## natebuchholz (Sep 28, 2013)

Linwood said:


> "The great thing about RODI water is you are in complete control of your water.
> 
> The bad thing about RODI water is you are in complete control of your water."​:wink:


Great quote


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## larusaquarium (Feb 21, 2015)

Thanks for taking the time to explain this in detail to me Linwood. I really appreciate it. I have one more question for you. 
If I use alkaline buffer do I need to use acid buffer too? Because according to the email I just receive from seachem they highly recommend using all three (equilibrium, alkaline buffer and acid buffer) together. How important is acid buffer? According to seachem reply they made it sound like I need acid buffer to balance out the spike of PH from alkaline buffer.


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## schnebbles (Jan 10, 2015)

On this subject don't you need to mineralized the water too? I added some tap back to my ro to put minerals in but it raised my pH a lot with even a 1/5 ratio


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## natebuchholz (Sep 28, 2013)

"Remineralizing" is what's being done by adding the baking soda and equilibrium. GH and KH essentially are measurements of minerals dissolved in the water.


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## schnebbles (Jan 10, 2015)

Oh. So to keep my pH and gH lower I should just do Baking soda and equilibrium. OK. I'll get some equilibrium then.


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## Raul-7 (Oct 17, 2003)

FreshPuff said:


> I would recommend only using Seachem Equilibrium. Your PH is fine and I wouldn't worry about KH measuring 0. It is much easier to keep your water parameters stable this way.
> 
> I hope this answers your question.


I would. It's not safe; the bacteria in the nitrogen cycle require carbonates, acids from decaying organics use up your carbonates and injecting CO2 creates carbonic acid which further does this. 

Your water does need a buffer. 



Honestly, I just use a media bag with crushed coral and place it in the sump. This way the water is always buffered.


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## Linwood (Jun 19, 2014)

schnebbles said:


> Oh. So to keep my pH and gH lower I should just do Baking soda and equilibrium. OK. I'll get some equilibrium then.


Baking soda (Alkaline Buffer if from Seachem) is one of the chemicals that raise PH. 

Equilibrium is "other stuff not very related to PH". 

Remineralization is a bit of both. 

The chief difference is that the KH (Carbonate Hardness, sometimes dKH for Degrees of Hardness) is strongly related to PH, and GH (General Hardness) is other stuff that should be dissolved in water that generally does not affect ph (this is a conceptual distinction and is somewhat incorrect and omits a bunch of details but is a good way to approach it). 

KH is often called "buffer". Think of KH as a "shock absorber" of sorts, the more you have, the less chemical reactions can change the PH of your water. Stuff is happening in your tank all the time, some of that stuff produces more acid (CO2 dissolving from the air or emitted by plants when the lights are off, rotting food and the nitrification process), some is consuming that acid (plants consuming the CO2 in the water, reactions with some rocks or other materials)

The more KH you have (within reason) the less your PH varies during these events. Put another way, with very low KH, the tank's ph varies more due to small, natural reactions, and is less stable.

Now there are other issues, for example at higher PH iron tends to not be available to plants for as long. And some fish and plants thrive better in lower PH or lower hardness. So this is not a case of "more KH is always better", not saying that at all. 

But like so many things, the extremes are rarely good -- truly zero KH is bad, as is very high KH. Pick a value recommended for your fish and plants, and aim for it. You'll find you miss (too many variables you will always miss a bit), adjust over time for your particular tank, adding a bit more or less as you remineralize. For an established tank make changes slowly and let everything adapt, no matter which direction you are going.

Oh... always remineralize water for water changes, and do NOT remineralize water added for top-off due to evaporation, as that has evaporated as pure water leaving minerals behind.


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## kilauea91 (Sep 19, 2013)

larusaquarium said:


> RO DI water contains no chlorine, therefor no need to add prime or and water conditioners. When you add prime to RO water it messes up the PH levels, lol.
> My question is not about using prime or water conditioners. My question is, do I need to add anything other than seachem equilibrium?


Not sure what kind of RO system you've got, but be careful when assuming no chlorine in the RO water it produces.

Chloramines

You can jump to 2:00 mark to see potential reaction chloramine can break down to NH3 and chlorine in the RO system. BRS has lots of video covering this topic while promoting their RO system.


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## Clear Water (Sep 20, 2014)

Whats your ph, kh & gh of your tap water? For me I add back tap water to my ro water to get my kh were I want it. I boast gh with a seachem product and then adjust my ph were I want it. Are you using a water tank to store your water? There a lot people that will tell you to forget ph it doesn't matter but mine comes out pretty high. 

Also how many stage ro unit? There are tons of informant on the net and you need to read more about this we here all have different ideas on water and what's good and what's not.


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## Clear Water (Sep 20, 2014)

FreshPuff said:


> I would recommend only using Seachem Equilibrium. Your PH is fine and I wouldn't worry about KH measuring 0. It is much easier to keep your water parameters stable this way.
> 
> I hope this answers your question.


I disagree. KH & gh is very important to your plants and fish. They will suffer over long term with little or no kh or gh. I use 20 to 10% tap water with my ro water to raise kh. Most plant like a ph around 7.0.


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## Linwood (Jun 19, 2014)

kilauea91 said:


> Not sure what kind of RO system you've got, but be careful when assuming no chlorine in the RO water it produces.
> 
> Chloramines
> 
> You can jump to 2:00 mark to see potential reaction chloramine can break down to NH3 and chlorine in the RO system. BRS has lots of video covering this topic while promoting their RO system.


A good, slightly more technical description of this is here.

Anyone with an RODI system should check with their water company to see if they use chloramines, and if so do some research as to their system and how to adjust.

A lot of what you hear/read on line is confusing. Consider the above you-tube - their discussion (at 1:30 and starting at 2:00) concerns ammonia getting through moreso than chlorine, for example, yet most discussions focus on chlorine (in fact the link I posted is testing for chlorine not ammonia, and it claims the DI resin takes care of substantially all). 

The test kit mentioned here is expensive, like $80 or so for a very few tests, so finding out how effective your system is costs quite a bit (enough to replace the prefilters and carbon blocks more aggressively which will remove more). 

My personal opinion is that the importance of this (assuming you have chloramines) varies a lot by how people approach their RODI system. If you buy a low-end system (1 stage for each filter), cheap prefilters (especially carbon) and use them a long time, you are more likely to have problems. If you have more stages (especially carbon), buy quality prefilters (or special ones for chloramines), you are at the other end and unlikely to have issues.

Unfortunately knowing for sure is expensive (the kit mentioned for a few tests was $80 or so). I'd love to see more people doing as this article did, and spending the money on testing (ok, so I'm cheap).


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## FreshPuff (Oct 31, 2011)

Raul-7 said:


> I would. It's not safe; the bacteria in the nitrogen cycle require carbonates, acids from decaying organics use up your carbonates and injecting CO2 creates carbonic acid which further does this.
> Your water does need a buffer.
> Honestly, I just use a media bag with crushed coral and place it in the sump. This way the water is always buffered.


Many aquarists use ro/di water and Seachem Equilibrium alone, with no ill effect. I believe Tom Barr also does this for one of his larger tanks. Let's not scare the OP.


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## FreshPuff (Oct 31, 2011)

Clear Water said:


> I disagree. KH & gh is very important to your plants and fish. They will suffer over long term with little or no kh or gh. I use 20 to 10% tap water with my ro water to raise kh. Most plant like a ph around 7.0.


I suggested adding the Equilibrium in order to raise GH to the desired level. That should be the main thing to focus on right now. If trouble arises in the future then try the buffers out. But I think people don't realize how important stability in an aquarium really is. It will be much harder to acquire stability using these water buffers. 

larusaquarium: I would follow Clear Water's suggestion on mixing tap with ro/di before using the seachem buffers. 
Also, you should read up on what Hoppy and Plantbrain (Tom Barr) say about gh and kh. These guys go in depth and are very knowledgeable. Use the search feature to find the info.


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## Linwood (Jun 19, 2014)

FreshPuff said:


> Many aquarists use ro/di water and Seachem Equilibrium alone, with no ill effect. I believe Tom Barr also does this for one of his larger tanks. Let's not scare the OP.


I think there have been two things mixed up. 

Using NOTHING is bad, and causes all sorts of issues. Bad. Very bad. Not a controversial issue as far as I can tell.

I think (emphasis on think) that having zero, really zero Kh is bad, and I think that is also not controversial. That is different from "do not add kh" of course. I think (emphasis on think) that there is SOME kh effect in Equilibrium, though small. My guess is using it alone provides adequate kh for nitrification (for example), though I still think adding some minimal amount of kh explicitly is useful. I'd be curious if anyone has tested RODI water with just equilibrium to see if it shows KH?



FreshPuff said:


> But I think people don't realize how important stability in an aquarium really is. It will be much harder to acquire stability using these water buffers.


Again, I think there are two things being confused. One is "Acid buffer" which I think does a disservice to everyone with the name and instructions. I agree, and got straightened out and stopped using it. Fundamentally anything you ADD to REDUCE ph is going to be problematic (other than co2 of course), some more than others, but mostly you need to remove stuff to reduce ph (and you removed it all in the RODI process). 

So in that sense I agree - stay away from "Acid buffer". 

But kh buffer is a normal and natural component of water and increases ph stability, not reduces it. The side effect is that the water is more alkaline, so you have to choose how much you want, including darn close to zero.

But I do not think it is fair to say that kh buffer (aka "Alkaline buffer" from seachem, or plain old baking soda) is something that causes instability. Where it does cause instability is if you add too much, then try to neutralize it with various acids. Which is exactly what Seachem promotes -- add lots of Alkaline buffer then add acid buffer to counteract. So I think we agree there, just don't assume that because both are bad together, that each is bad individually.



FreshPuff said:


> larusaquarium: I would follow Clear Water's suggestion on mixing tap with ro/di before using the seachem buffers.
> Also, you should read up on what Hoppy and Plantbrain (Tom Barr) say about gh and kh. These guys go in depth and are very knowledgeable. Use the search feature to find the info.


Mixing tap water with RODI water is not a bad thing, but it is a bit of an ironic thing, really. For fresh water tanks, it is questionable if you need the DI stage at all, or even if you need RODI water at all. Heck, I bet just the pre-filters is all most people really need -- take out chlorine, organics, most of the pollutants, etc.

But if you start with the assumption your water is very bad, OR you are a bit compulsive and like to be in complete control -- why go backwards? Once you get to 100% in control (the output of RODI) of what is going in your water, why give up 20% of that control by mixing tap water back in? 

Possible good reason: It's cheap. OK, fair enough. Though it's cheaper to use tap, or just filtered, or just RO. All of those would generally not need remineralization (well, RO depends on target environment). 

But if you are doing it because you think it is somehow *better* to mix with tap (as opposed to cheaper), I disagree. Once you go down the expense and trouble of getting essentially pure H2O from the RODI, it seems to me you might as well finish in full control -- decide what you want in it, and add it yourself. If you didn't trust your city water for 80% of the water, why trust them for 20%. 

Will it do any harm? Probably not. But frankly probably 100% tap would would be fine for most of us who do RODI for fresh water. It just seems a bit contrary to the reasons most people do RODI in the first place.

PS. And for corrosion control must municipal water supplies add lots of KH to water, so adding back tap water IS adding Alkaline Buffer, most likely.


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## imcmaster (Jan 30, 2015)

+1 for everything Linwood is saying.

I just want to clarify Seachem's position.

First consider that a buffer is, by definition, something that resists a shift in pH. An ideal system has both an alkaline buffer (to resists changes from acids), and an acidic buffer (to resist changes from bases).

If you want to set a target pH (which you shouldn't need to), you would mix both the alkaline buffer with the acidic buffer in the appropriate ratios to end up with a stable ph, in that both buffers exist in enough quantities to do so.

Of course you don't need to add an acidic buffer, as tanks naturally have acidic buffers established by the use of driftwood, peat, almond leaves, etc, but again backing Seachem, it would not be considered wrong to mix together both an acidic buffer, and alkaline buffer, maybe in a ratio of even 1:10. 

I am not endorsing this approach, but agree with it's validity.


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## schnebbles (Jan 10, 2015)

so, equilibrium will not change pH while changing gH? my pH is way higher than I want it when I add tap water back in. If my RO is 7 and I add equilibrium to make my gH, 3, my pH should stay at 7, but I'll still have no kH? which means adding something that will raise my pH. I don't see how I can get my pH to a lower number then. I don't like the tannins in the water from leaves, etc.


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## imcmaster (Jan 30, 2015)

schnebbles said:


> so, equilibrium will not change pH while changing gH? my pH is way higher than I want it when I add tap water back in. If my RO is 7 and I add equilibrium to make my gH, 3, my pH should stay at 7, but I'll still have no kH? which means adding something that will raise my pH. I don't see how I can get my pH to a lower number then. I don't like the tannins in the water from leaves, etc.


Equilibrium is used to restore minerals to RO/DI water. The gH will raise as a result (and not pH). You dose according to the level of gH you wish to obtain.

You need to establish a buffer to RO/DI water. If the effect of the addition of an alkaline buffer alone results in a pH which is too high, then you must also add an acidic buffer. The net effect of the two buffers will result in a pH which is more neutral than either on it's own. The ratio of the two will need to be established to get the desired pH.


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## Linwood (Jun 19, 2014)

schnebbles said:


> so, equilibrium will not change pH while changing gH? my pH is way higher than I want it when I add tap water back in. If my RO is 7 and I add equilibrium to make my gH, 3, my pH should stay at 7, but I'll still have no kH? which means adding something that will raise my pH. I don't see how I can get my pH to a lower number then. I don't like the tannins in the water from leaves, etc.


In a loose sense your statements are correct, but the details mean that the implication is wrong.

I'm testing my chemistry from too long ago and some recent reading so someone jump in if I get this wrong.

The PH of pure water is indeed 7, though only at standard temperature (25C or about 77F).* And only in a sealed container with no air contact.* So people who say "RODI water is PH=7 by definition" are both completely correct, and absolutely wrong. 

See... you don't keep RODI water sealed away, you put it in a tank and aerate it (I'm not even talking about tannins, etc., just plain old air). Pure water absorbs CO2 from the air, the CO2 forms carbonic acid, where each molecule of CO2 releases 2 hydrogen ions and quickly makes the water pretty acidic. All by itself -- just water + air. Take RODI water and aerate it well and it will absorb somewhere around 2-3ppm of CO2, and PH will be in the 4-5 range. It may not MEASURE in the 4-5 range, as accurate measurements are quite difficult in pure water. But it is nowhere near 7. 

There are two things I am trying to explain, one is that the "RODI water has exactly PH=7" is widely quoted and very misleading, and secondly the reason it can change so strongly with just air is that there is nothing to interact with the Co2 in solution, as much as possible (at temperature and pressure) interacts to form acid, and there's no where for the acid to go.

In water with some buffering, this acid can be absorbed, sort of stashed away, in other forms that does not contribute loose hydrogen ions, and so do not make the water so acidic. This buffering is something of a shock absorber, so the swings are smaller. 

So to your question, raising the GH in principle does not change your PH -- but it isn't really at 7 to start with either. Two things happen -- first, the GH probably has some buffering effect, and secondly the water wasn't at 7 to begin with once it got to the air. So you get some other value -- not sure, I would GUESS in the low-mid 6's. Try it and see. 

So that's why you can still add some KH (whether explicitly, or in contents of the tank, or maybe some is in Equilibrium), and not end up above PH=7, the Co2 alone will keep it lower than 7 for a while. Two things are happening -- one is that it is raising the PH (but you are starting at 4-5 somewhere), but it is also reducing the swing of PH from CO2, which also is going to raise the PH.

That's why it does not take much KH at all to get you over 7. But you can put in some and still end up below 7 once the tank reaches equilibrium with Co2 in the air.

Here's a chart that may help:










It comes from the Barr Report forum by the way. It is for injected CO2, but if you think about CO2 at about 3ppm, you can mentally draw a curve that more or less paralles the green but is further to the right. If you read them off, you can see approximately what the "normal" PH will be due to pure water plus regular CO2 just from exposure to air, here are some values: 

dKH=20, ph=8.3
dKH=10, ph=8
dKH= 5, ph=7.7
dKH= 3, ph=7.45
dKH= 2, ph=7.3
dKH= 1, ph=7.0
dKH=.5, ph=6.7
dKH= 0, ph=somewhere between 4 and 5 (not shown)

What I don't know is how much KH impact Equilibrium has. I don't think it is zero, but I suspect it is low. And obviously may depend on how high you take GH. If you have a very accurate PH kit, you can tell by aerating water mixed with it and see, just look it up on the chart.

If you find it is off the chart low KH, and if it was me, I'd still add a bit, say enough for 0.5-1 dKH or so, just try have SOME buffering in there for stability, and some carbonate and sodium for the nitrifying bacteria.


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## schnebbles (Jan 10, 2015)

ok, thank you so much. Linwood - my parents live down there! I wish I did. Was just there 2 weeks ago.

I tested my water today - last water change was Sunday. my gH is back to 0 and kH is 5 - with pH still being high at around 8.

I thought I wrote down my levels last week but apparently not, I know my gH was up to at least 5 and kH was higher as well. With plain RO, gH and kH were both 0

I'm buying equilibrium today and will put it in tomorrow when I do my water change and go from there. I'll figure what gH I want and measure the other 2. 

I had no idea water would be such an issue. In the past, I've had fish tanks and just used whatever water came out of my sink!


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## Linwood (Jun 19, 2014)

schnebbles said:


> I had no idea water would be such an issue. In the past, I've had fish tanks and just used whatever water came out of my sink!


Honestly for most people that is probably the best idea (with dechlorination of course).

Simple is not a bad thing.


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## schnebbles (Jan 10, 2015)

lol! I was almost thinking that myself. My husband thinks I'm insane all of the RO water I get and water changes. He says people just put water in and add fish, end of story. That's about what I used to do and I really never had problems. Never had a planted tank though. 

I am surprised my paramaters changed that much in a week though, shows me I need some stabilizer.


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## Linwood (Jun 19, 2014)

schnebbles said:


> I am surprised my paramaters changed that much in a week though, shows me I need some stabilizer.


Yeah, I'm not following that either. 

Can you refresh my memory, what do you think your parameters were a week earlier?


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## schnebbles (Jan 10, 2015)

I forgot to write them down. On second thought, I may have only tested the water I added to the tank (water change). I bet that's what I did. Only a week and I don't remember. 

Well, either way, I'm going to get the equilibrium and go from there.


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## Linwood (Jun 19, 2014)

OK. Generally speaking the kh and gh should change slowly in a tank, if not something else is going on. Increases in kh for example can come because of the type of rocks. Decreases can come from consumption by various processes that are normal, but should be slow. GH even more slowly.

Rapid changes in one or the other, frankly, are probably more about measurement error than something in the tank. One piece of advice -- whenever you see some huge change you don't expect, don't immediately react. Take the time to retest, rethink, etc. Reacting, e.g. dumping in something to "fix" the sudden change, is rarely a good idea. Not that you said you would, just saying...


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## schnebbles (Jan 10, 2015)

I'm pretty sure I only tested the water I changed with. So that would explain it, I have a 40g and changed out about 17. I had only RO in before that. 

I don't have a rock so it can't be anything like that. Just plants and 2 pieces of wood. Spider wood and manzita (sp?) wood. 

This time I wrote down the tank water so I can keep track.


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