# pH, KH, CO2, and water changes



## dogdoc (Feb 3, 2006)

I have some concerns with my setup. It is 75 gal planted with 120 lbs of Eco-complete substrate. I have just started pressurized CO2. I have very funky tap-water. It has 3 dKH, 4 dGH, and a pH of around 8.0. 

With those numbers, I have been setting my pH monitor at about 6.6 to maintain around 25-30 ppm CO2.

I have been advised that I should boost my KH up to 4-6, and my GH needs to come up as well. My concern is at water change time. I use a python so water goes directly back into the tank. If I am doing larger water changes (40-50%) as recommended with EI ferts, will adding baking soda or alkaline buffer at the same time and the big pH difference from tap to tank cause my fish any troubles?

How would you accomplish the KH increase without stressing the fish?


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## Ben Belton (Mar 14, 2004)

I'll offer you an answer you didn't expect. 

My 75 has a KH of around 1-3 and a pH of about 6.1. The soft water plants love it and the Rainbow Fish and Angels spawn and play all day. My plants pearl and grow like crazy. I doubt I can grow Val, but I haven't tried it.

I don't see any reason for you to change. 

Ben


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## Bert H (Mar 2, 2004)

There's nothing wrong with your kh or gh. *DON'T* add buffer to change pH!!! To test your tap pH, did you let it sit overnight before measuring it? I ask because I find it odd your pH should be so high, when your kh is at 3. To give you a comparison, my kh is 9 and my pH is 8. You might want to get a report from your water company.


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## dogdoc (Feb 3, 2006)

Yep, I have let it sit overnight before testing. I know, it is screwy water. In the summer, when I first set up a tank, the pH was lower. Around 7.6. When I first hooked up the CO2 the other day, my tank pH was actually 8.2. I have actually asked about my wierd water on other forums, and nobody really seems to understand it. I have called the water company for a report. They never call back.

I'm actually happier if I don't have to mess with the pH or KH. Less to worry about at water change time.

Actually, my Val is growing gangbusters, and is one of the plants that did fairly well with no CO2 or ferts.


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