# confusion: adjusted KH, and Co2



## oregon aqua (Jan 30, 2008)

i was adding my usual 1 tablespoon of baking soda that normally brings me up to about 5 kh from 1deg kh.
well i knocked the tin in and it had about 3 to 4 tablespoons in it. i had to go to work so i hoped for the best and left.

for the next 5 days my plants were pearling way more then normal. even some new plants that where just added. testing with my kit i had 14deg KH. 

i run a ph controller set at 6.5 and i have noticed it runs longer to get to 6.5. 

what i think i know is, a high KH makes ph take longer to change because its more buffered.

now for my confusion. raising KH does not raise Co2. does raising my Kh totally void the KH PH chart. in my assuming i was using my adjusted KH from 4 or 5 deg for my co2 calculations but now i know that for sure was wrong because 133ppm ROFLMAO. i figured it wasnt acurate but had to be close LOL again.

does raising my Kh with baking soda allow...... more Co2 to stay in solution in water? 

in other words why did i get so much more pearling? i did my water change now and i dont plan on a replay of my accident but i am interested in what happened. all the fish and plants seam happy.

im going to start PPS-Pro so i need to know how to see my co2 for sure so i can adjust my Co2 down to 15ppm. with e.i. dosing i raised it up untell the fish respired at top and then backed it off a little. i hated doing it this way but it was the best way i could be sure i was near the 30 to 35ppm Co2. i guess i could get a drop checker set at a base kh but im in to the no equipment in my tank thing. 

and with adding magnesium and potassium sulfate will this increase my kh/gh? i have no idea what my gh is its either 0 or well above 20 ppm or im just to colorblind to do the test

thanks in advance to anyone who can decipher my rambling and answer me


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## ngb2322 (Apr 9, 2008)

Raising KH means that it takes more CO2 for your controller to maintain the given pH. Check the calculator on http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm
And yes, your CO2 in ppm with a pH of 6.5 and KH of 14 is 133ppm. Might want to get that down.....your biological filter as well as any fish in your tank will probably be adversely affected by such high CO2 levels. I'm not sure how to handle your situation though.... I would probably do 25-50% water changes 1xday WITHOUT adding baking soda over the next few days until your KH returns to normal. Hope that helps.


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## oregon aqua (Jan 30, 2008)

thats what i was thinking but 5 days of 14kh and 6.5 ph...133ppm co2 all my fish should be dead. but thier not even up at the top of the water. in fact my danios made fish food....i mean laid eggs. not what i would expect from such a high co2 level. 

i have now completed 3 water changes in 2 days and seem to be back at 6 kh without adding baking soda. ive noticed sometimes my Kh will climb a little so i will keep an eye on it. 

today marks the first day of my pps-pro still wondering about my other question if anybody has an answer?


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## hoppycalif (Apr 7, 2005)

This is one more of many examples of why you can't measure the ppm of CO2 in an aquarium by just measuring the pH and KH. You will almost always get a much too high reading when you try that. 100+ ppm of CO2 in an aquarium would be lethal to the fish. Much above 40 ppm is lethal to fish, based on my experience with "end of tank dump", otherwise known as rising output pressure as the input pressure to the regulator drops. Drop checkers are not perfect for measuring CO2, but they are far more accurate than using pH and KH of the tank water.


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## Squawkbert (Jan 3, 2007)

If you need a certain amount of bicarb to maintain a desired KH, you should figure out how much per gallon it takes, then use that as a guide to making your replacement water for changes. From there, you replace evaporated water w/ dechlorinated tap water and use a drop checker to bump your CO2 delivery until you're somewhere between 15 and 30ppm.

This leaves you 1) never having to add bicarb to your tank, thus altering its buffer capacity and (potentially) pH quickly 
2) not counting on a pH controller to meter your CO2 as they can OD your tank, killing your fish. IMHO, pH controllers are best used in Ca reactors, by reefers. 
3) not needing frequent KH tests (that are not so accurate anyway as they have a tough time differentiating general from carbonate hardness).


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## thefishmanlives (Feb 15, 2008)

This should show you that you rco2 neeeds to be raised. All those plants should have been pealring like that all along. I realized all this co2 info lately is true. kh/ph based co2 readings are waaay off.


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## nopain00 (Jun 12, 2006)

The whole KH/CO2/pH relationship assumes that the only components that are contributing to the pH are the bicarb (KH) and the acid (CO2). In most cases there are other buffers and chemicals that are also changing the CO2.

For a quick check to see how close the reading is going to be, take a sample of your aquarium water and put it in an open bowl for a couple of hours. You can stir it occasionally. This will "degas" it, reducing the CO2 dissolved within it down to an equilibrium with atmospheric air (approximately 3 ppm). Now, do your usual calculations on it by measuring KH and pH. If you get a CO2 reading of much greater than 3, then you know that there is something else (phosphate, etc.) that is contributing to the pH reading.


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## Edward (May 25, 2004)

Hi
You are incredibly lucky to have 1 degree KH on tap, enjoy it! Don't add any pH modifiers or baking soda. Disable your pH controller, you don't need it, it doesn't do good job. Set your CO2 needle valve to few bubbles per second depending on the aquarium size, 1 for small, 3 - 5 for large aquariums. Forget about pH, don't need to test for it, same for KH. 

What is your dGH? Most likely quite low so get a Ca test kit instead, and keep Ca levels at 20 - 30 ppm with CaSO4. Simply dose dry after water changes or monthly a teaspoon or two will do. Dose PPS-Pro daily and enjoy. You can grow anything you want in water like this. 

Thank you
Edward


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## oregon aqua (Jan 30, 2008)

> Hi
> You are incredibly lucky to have 1 degree KH on tap, enjoy it! Don't add any pH modifiers or baking soda. Disable your pH controller, you don't need it, it doesn't do good job. Set your CO2 needle valve to few bubbles per second depending on the aquarium size, 1 for small, 3 - 5 for large aquariums. Forget about pH, don't need to test for it, same for KH.
> 
> What is your dGH? Most likely quite low so get a Ca test kit instead, and keep Ca levels at 20 - 30 ppm with CaSO4. Simply dose dry after water changes or monthly a teaspoon or two will do. Dose PPS-Pro daily and enjoy. You can grow anything you want in water like this.
> ...


i have tried to test my dGH and my test kit shows no change up to 20 drops. i always assumed that it was way high. not sure why i thought that but i did.

when i used to do diy co2 i would have the most unbelievable ph swings so i would add baking soda to help out and save the fish. i have never tested Ca before so more fun with colors for me=0)......

that brings me to the ph controller. some like them, most dont but im color blind and red green blue start to look the same when im doing water test so the ph controller was a easy fast fix for me and has made my wife happy because i dont go "hey honey what color is this? and does this match here or here?"

i started pps-pro on my 46gal corner tank. it gets excel no co2 80 watts power compact and thats it. i have high hopes for this tank!!!!

my 55gal the tank that had the accident is going to mineralized substrate so no dosing.

and my 4gal nano is going to be NPT if i ever get the nerve to flood it from its emerse growth.

so far i have been very happy with your pps-pro the plants are mostly happy and the fish seem much more active. i have some cloudy water going on and some gda but thats it.

after many many years of trying to do planted tanks im trying to find the routine that works best for me=0)

thanks for reading my ramble 
jeremy


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## TortoiseBoy (Dec 30, 2004)

Hi Jeremy,
Your situation is very similar to mine. I also have very, very soft water and I am color blind with a wife that gets tired of reading the color charts ;-)

PPS-Pro has worked pretty well for me, as well. The only problems I have found is the Ca/Mg ratio which I am trying to get dialed in. I have ended up with severe Ca deficiencies (I think, anyway - severe curling and notches in some leaf margins) in the past, even after adding significant amounts of Ca in the form of CaSO4. I am going to be experimenting with ratios between Ca and Mg because I am thinking this may be where my problems lie. 

On the whole, I agree with Edward that we have perfect water and can grow anything in it. What I am trying to figure out is how to capitalize on the perfect water without having to add so much Ca/Mg to the point where it is just like everybody else's tap water ;-) I don't have it dialed in yet, but I can still grow Tonina belem really well, so I haven't erred on the too-hard side, either.

Let me know if you come across any breakthroughs, and I will try to let you know if I ever figure out the curling/incomplete leaf margins in my tank. 

Best of luck,

TB


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## Edward (May 25, 2004)

Hi TortoiseBoy
There is no need to add Mg, plants don't care about ratios. PPS-Pro adds the right Mg amount for you in small daily additions. If you like experimenting you can test for the basic three, NO3, PO4 and Ca. If these are in order (5 - 20 ppm NO3, 0.1 - 2 ppm PO4, 20 - 30 ppm Ca) then try extra daily dose of 0.4 ppm of Ca from CaCl2. For reference, 59 grams CaCl2.2H2O in 1 liter, dose 1 ml per 10 gallon => 0.4 ppm Ca. Start with ¼ the 1st week, ½ the 2nd week, ¾ 3rd week then the full dose. This may help, let us know. 

Thank you
Edward


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## TortoiseBoy (Dec 30, 2004)

I will give it a try, Edward. Thanks for the reply.


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