# K.H and P.H balance help



## thunderjack14 (Nov 28, 2014)

Hello everyone!


I having a hell of a time with the K.H and The P.H balance according to the co2 charts. When i try to bring my K.H down to 6 for the plants it lowers the P.H. Then i bring the P.H up with seachem buffers and the K.H goes up as well. now im using the two seachem acid buffers as well as alkaline buffers and still cant get it right . any help please.


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## Gilby (Feb 15, 2014)

As you have observed, KH and pH move together. You are essentially mixing baking soda and an acid (such as vinegar) and doing the volcano experiment in your tank. If you need a target KH and pH, you'll need to your alkaline buffer to get the KH where you want it, and then to reduce your pH you'll need to add CO2. What KH and pH are you trying to get and what purpose do you want those parameters?


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## thunderjack14 (Nov 28, 2014)

K.H 6 and P.H 7.5 the reason why i would like to reach this target is because i have a 150 gallon tank with java ferns and sword along with anubias plants in a african chiclid tank. Plants like a K.H of 4 to 6 and the cichlids like a P.H at 8.2. and at the same time i'm injecting pressurized co2. The chart say at 7.5 and K.H at 6 you would reach 30 ppm of co2. Now i know when the co2 is on for a few hours the P.H will drop and when the co2 go's off then the powerhead comes on and P.H go's back this is normal. I just cant get a steady P.H at 7.5 and K.H at 6 as a starting point. any help would be great thanks in advance.


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## thunderjack14 (Nov 28, 2014)

Do you think my plants will do well in high k.h ? and high p.h i know they are a hardy plant but everything has a limit.


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## Gilby (Feb 15, 2014)

Yes, your KH could be 14 dKH with those plants, maybe even higher. The bigger issue is whether your plants will get eaten by your fish. The anubias will probably be fine. I had anubias, valisineria, and a radican sword in a mbuna (lake malawi african cichlids) tank. The anubias and val did fine, while the sword didn't have much in the way of leaves. The sword still survived, as when I later tore down that tank and put the sword in another tank (with tetras, cories, etc), it grew normally, which for this sword was too big for that tank (and most tanks). My mbuna tank did not have co2, so I didn't have to worry about too low a pH for the fish, and my tap water is liquid rock, so the fish were happy. For african cichlids, the addition of co2 may drop the pH too much for them to be happy, but most references say it can be 7.5. Some people with planted tanks have gone lower than that. Your plants will be fine in a low tech setup (w/o co2), but if you want to get your co2 up there to increase plant growth, you can try to push below 7.5. Alternatively, you can use excel/glut as a carbon source in addition to using co2 to set the pH at 7.5.


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## thunderjack14 (Nov 28, 2014)

Hello gilby!

Well i did a test of the water this morning before the co2 came on my P.H was at 7.9 and the K.H was way out there at 18. so i used seachem acid to drop P.H at 7.6 and at the same time the acid will dissolve some of the K.Hand turn it into co2 this will lower my K.H a bit i will check again after the co2 is off and do another test but if it can just stay around 7.6 i could live with that now that you say that the K.H that high will not harm the plants. I know if you have a higher K.H the P.H swings will be more stable with the co2 running in the tank this fluctuation will not harm the fish. But until i get the P.H and K.H around where i need them i will adjust slowly a bit every day. thanks for all your help i will keep you posted if i run into more trouble lol lol ...thanks again


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## Gilby (Feb 15, 2014)

You are throwing too many chemicals into your tank which is going to be very hard to repeat when you do water changes, and it's probably stressing your fish with all the fluctuations. I'd recommend you throw out your acid buffer, and only adjust your tank by doing water changes. Start by testing the KH of your tap water and then when doing water changes only using a chemical, such as alkaline buffer, baking soda (sodium bicarbonate), or potassium bicarbonate to raise your KH if needed. If your KH target is higher than your tap, you add the alkaline buffer per the instructions on the label to get to that desired KH when you do your water change. It looks like that is 1 teaspoon for every 10 gallons to raise it 5.6 dKH. You then adjust your co2 to lower pH to 7.5, and try to keep your pH steady day and night by how much co2 you inject into your tank.


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## Tugg (Jul 28, 2013)

In short, Acid buffer simply converts KH into CO2, which then partially becomes carbonic acid; in effect reducing the kh buffering, and temporarily lowering the ph. As the elevated CO2 is outgassed the ph will go back up to whatever it's equilibrium levels are with the new reduced kh level.

Acid buffer is a product to use during water changes to reconstitute water so it's CO2, Kh, and ph match the tank, reducing stress. It's not something I would ever recommend adding to adjust the tanks kh, ph, or co2. The only intank method to adjust ph I would recommend is the use of CO2. Something that just doesn't make much sense on an African tank.

The plants hardy enough to hold up in that tank are tough and slow growing. They don't need elevated CO2. Some plants such as Vals actually consume kh as a carbon source, and do better in a higher kh tank.


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