# TDS - GH - KH - Are my results good? I Don't understand.



## Jafooli (Feb 9, 2013)

Hi

I was hoping someone could help me understand my results because I have no idea what they all mean. 

I purchased a TDS meter and a GH/KH api test kit as my girlfriend keeps shrimps and we lost 10 Yellow Shrimp slowly over months, and then purchased 10 RCS and 5 months later we are down to 4 remaining, we've never seen a berried shrimp yet. Anyhow I would also like to know about GH&KH as I have a 200 litre tank but have not yet tested it and I'm the one who mostly looks after the shrimp also which I am failing at miserably.

Here are the results I have no idea if they are good, from my quick research I think they may be good. 

Fluval Ebi Tank

Before W/C "Saturday" 271 TDS
After W/C - "Sunday" 300 TDS
"Monday" 300 TDS

Today's results for GH&KH 

12 drops GH.. 214ppm? 
6 drops KH 107ppm? 

I also x the drops by 17.9 to double check and sounds right? I have no idea what I am talking about lol.

Anyhow after some research I found a site that say's.. Cherry Shrimp:

PH: 6.4 – 7.6 KH: 0 – 10 GH: 4 – 14 TDS: 80 – 200 Water temp: 18 – 23

So I presume my GH is fine and my KH, and the TDS is not 200 but I read 200-500 was suitable. 

How do I understand my results do I use the ppm ? or each degree? "the drops" not quite sure how I would tell someone my KH, do I say its 6 drops? or 6 degree? or 107ppm? 

Hope this make's sense, I also don't understand how my girlfriends tank TDS went up after a W/C after sitting for about 30 mins saying people do a W/C when there TDS gets higher to lower it, so am bit confused with TDS etc, although I have bookmarked some good threads on here to try understand it. 

I also have not tested my GH-KH for my tank but I played around with the TDS meter and this was my results for my 200 litre.

Before W/C "Saturday" 490 TDS
After W/C "Sunday" 432 TDS
After Macro Dose "Ei Dosing" "Sunday" 5 mins later 450 TDS 
Next morning 359 TDS, Then added Micro Dose, 5 mins later 455 TDS

I am so confused by all that. 

I also worked out the buckets of water I add to the tank are 313 TDS and 320 with dechlor added. 

Hope someone can help me out here, and if anyone knows a lot about TDS, is all the ups and down normal? and do any of these readings ring alarm bells? 

Thanks in advance.


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## danielt (Dec 19, 2012)

TDS, depending on what the measuring device is capable of, reveals how pure is the water. Everything that can be dissolved in water releases something called ions. In water, all the substances that dissolve will transform in positive or negative ions. A TDS meter will count how many negative and positive ions are in the water. It's unable to distinguish if they're helpful or toxic.

What it's used for? TDS it's for fish like a barometer is to us. Too low pressure, not good, too high, also, not good.

For water living creatures, osmotic pressure is the thing we're trying to determine using TDS meters. However, this method is as precise as trying to measure wind power with a hand mill (google translate gave that term, hope it's understandable). You don't get an exact figure, you just form a basic idea if the wind is blowing strong or not.

TDS fluctuates because you dissolve substances in water. Ferts, food, hardness, byproducts from the fish, bacteria. They all account to some amount to the TDS value. Some of them more than the others. You can increase TDS by a whole lot by just adding Calcium Sulfate(gypsum) and allow it to dissolve, for example. Fish poop will account for less. Calcium ions are rather heavy so will account more to the osmotic pressure than fish poop.

Why is TDS DECREASING in a tank? Well, by now, you should have figured it out. There's less ions in the water! Who took them out? Plants, for instance, are very good at scrubbing the water of the stuff you and the fish put in it. They use it to make leafs and stems out of it so the TDS meter is unable to pick those up once they're in the plant. It will pick some but not as many.

Hope this clears things up.


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## Jafooli (Feb 9, 2013)

Hey cheers for the reply and explaining about TDS, its interesting to learn about it all and quite complicated at the beginning. I still don't understand how people use it to determine water changes but I've still got a lot of threads to read through so hopefully I will understand it soon.

I guess it might be better to post in the shrimp section to see if anyone can work out why my girlfriends shrimp are dying slowly. 

I also think I understand GH&KH a bit more, so at least I can post my results, the ppm readings confused me as most people post a number "degree" and not ppm but now I know a degree is a drop. 

Thank's for you help and helping me to understand better.


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## kcoscia (Jul 24, 2013)

I know that gH should be <4 and TDS pretty much tells you when your water has too much bad stuff in it and it's time to change. 200+ i think?

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## Jafooli (Feb 9, 2013)

Hey kcoscia

Thanks for info, dam do you mean my GH should be 4 or 8? that would explain why the shrimp are dying slowly, if mine is at 12 :O how do I go about brining it down? I presume I'm need to look into a RO unit? I thought my GH was fine from what I did on research and asked some ebay sellers. 

I was hoping I wouldn't need to go down the RO route but if I was to get a RO unit that would hopefully lower the TDS also?, so then I could get it to 200? but for my tank with 490 TDS :O would that still be ok as I don't keep shrimp in there, just oto's and corys and tetra's which I hope are fine. I've never really researched what my GH/KH & TDS should be for all my fish.


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## danielt (Dec 19, 2012)

Fish, for once are more complex organisms. They do have abilities that shrimp lack. That's why shrimp are so damn hard to be kept alive 

As I said previously, TDS is believed to be a water quality test. That is true for the water purification stations which use TDS meters to determine haw bad is the water instead of doing lots of tests to measure each substance. It's a bulk measurement, however, that measurement is also meant for human consumption.

In an aquarium I think it's wrong to rely on TDS to determine when to change water. Why? Because you can have a high TDS due to Ca and Mg ions but the water is still good.

For instance, I recently did a water change using RO only (TDS 005ppm), added Calcium and Magnesium sulfates. Nothing else, TDS went to 250ppm. This was needed to increase hardness (gH) to a 5 dgH (german degrees of hardness). On the other hand, should I relied on TDS to show me when a water change needs to be done I could have accumulated lethal doses of Nitrates. That's why it's dangerous to rely on TDS alone to determine when you need to change the water.

TDS in one of my tanks is 550ppm, it's like that for some time now. I don't have a decreasing number of shrimp although I don't have an increasing one as well, in spite of berried females.

RO allows you to adjust parameters as you please. Increase and lower any kind of hardness. It offers flexibility. You can raise shrimp using tap water alone, as long as it's not extreme.


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## Jafooli (Feb 9, 2013)

Thanks for the reply, 

I will just leave my main tank alone then, It is mostly increasing after each dose of Macro or Micro from my EI dosing. 

On the other hand we didn't really want to purchase an RO meter unless necessary "to raise & breed shrimp", and from what I've read the water parameters should be in the acceptable range. From the results above of the GH & KH and TDS in the shrimp tank, if it was you or anyone else for that matter who breeds shrimp, would you be worried?


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## Diana (Jan 14, 2010)

GH is a measure of calcium and magnesium. Many kits use drops of reagent, so that each drop of reagent means 1 German degree of hardness. So 12 drops is 12 degrees of GH. If you multiply that by 17.9 you convert 12 degrees to 215 ppm or 215 mg/l. Parts per million and milligrams per liter are the same thing. 

KH is measured the same way. This is a measure of the carbonates in the water. 

Fish (I do not know about shrimp) are more concerned with the GH of the water. Soft water fish may be able to handle harder water (higher GH) but not always. Some soft water fish take in too much calcium when they are in hard water and die. 

KH is a buffer that stabilizes the pH. Most soft water (low GH) fish are also accustomed to low pH, and to get this the KH should be low. 
Most hard water fish (high GH) are accustomed to high pH, and to get this the KH should be higher.


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## danielt (Dec 19, 2012)

In my not that expert opinion in keeping shrimp, I know a lot about water but not much as I would like about shrimp, you should choose between plants and shrimp.

Sometimes they headbutt. EI dosing causes fluctuations in water chemistry that affects shrimp. You need to do a 50% water change at the end of the dose cycle. Which can prove stressful for them. Stability of the water chemistry is more important to shrimp than the numbers. What gH, what TDS? Doesn't really matter as long as it's not a bad value. What matters is to keep that value across water changes.


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## lipadj46 (Apr 6, 2011)

danielt said:


> Everything that can be dissolved in water releases something called ions. In water, all the substances that dissolve will transform in positive or negative ions.


This is not true. Not every soluble substance is ionic.

sent from an undisclosed location using morse code


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## Jafooli (Feb 9, 2013)

Hey danielt

Thanks for the reply, and sorry if it sounded like I was dosing EI in the shrimp tank, in the Fluval Ebi we have, we do not add anything, no fertilizers, no co2, its just plain tap water dechlorinated and a 20% w/c each week, and all water parameters are always stable and from what I read are in acceptable conditions, and also to add everywhere I do read this is what I normally come across, my cherry shrimps breed like rabbits, my cherry shrimp can survive anything, reading people say that frustrates me as mine fall like flies and I try my hardest to keep everything in tip top condition for them with the water I do have. 

We never understood why we kept losing a shrimp every week, till gradually we were left with 0. We started with 10 baby yellow shrimp, about 7 of them reached adult size, then slowly began to disappear till there was 1 that lived for ages. We removed him and went out and purchased 10 Red cherry shrimp from my local fish shop this time around, as we thought they would be more used to the water in my area, which sounded better than buying from ebay again where the water they are from could be different. We added all 10.. once again.. all baby's... 3 months later about 7-8 adults again, then slowly started finding a dead shrimp once a week, I have 4 left now.. was 5 but it got trapped in its molt, which I think was unlucky as never had that problem with the other dead shrimps. 

The 4 shrimps we have now seem to be going strong, my girlfriend said she won't be buying shrimp again, but I persuaded her to spend the money on a TDS meter, and a GH&KH kit, to try and let me help her solve the problem. I have since changed the water changes from 30% to 20%, I am also adding the water much slower, and also letting the new bucket of water sit for about an hour. 

I also changed the tank layout, and tried to make it more clean/simple while also providing plants and cover for the shrimp. I also am trying to encourage her to try and buy some moss for her tank seeing as every shrimp tank I find on youtube, or here has some kind of moss. 

I've told her to not buy no more shrimp yet and told her to let me see how long I can keep these last 4 shrimp alive, who knows If I can get one berried and keep her alive for 30 days, hopefully she won't need to go out and buy any.

Maybe it would be best for me to open another topic in the shrimp section regarding all this?

As for my main tank I presume TDS going up and down does not effect the fish then? as I presume everyone who does dose EI in there tanks would have the TDS go up, and then down when the plant's use the nutrients. 

I believe all my water parameters are stable, the only one's I now know that go up and down is TDS.. which sounds like it should be going up and down.. if dosing EI.. and ph goes up at night I presume when I switch my CO2 off.. and then down in the day when injecting my co2. 

My 200 litre tank is only 3 weeks old, so I also presume my TDS might still get higher? as the longer I dose maybe more nutrients will build up, I also can not do a 50% w/c on my 200 litre tank, so I do a 30% instead. So this I would have to keep an eye on I presume. Then when I see TDS climb to high, I could do partial w/c's till it comes down again. 

Thanks for everyone's help, I wish I had all your knowledge lol, but I do try to take in as much as I can and am learning everyday


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## Jafooli (Feb 9, 2013)

I also just measured my main tank and it got 8KH and 16GH, which wasn't even on the charts... and I can't find anyone or any thread where someone has a similar GH, so I have no idea what to do from here, I think if I start messing around with my water parameters it could make thing's worse all though I would like my fish to breed.

My PH was 7 which if you go by the CO2 chart I'm on 25ppm of CO2 .. and my drop checker is also green. 

So my only problem is this really high GH, does EI dosing make GH higher? I don't get why its so high.


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