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Discussion Starter · #1 ·
My water out of the tap is super soft. 3 degrees GH and 1 degree KH. Running CO2 this worries me because I do not have a lot of buffer for pH.

Have a couple questions on this.

1. Can I use baking soda to raise the KH and how over all will this affect other chemistry in my tank. I have used RO Right (into strait aged tap) and some other buffers and none seems to do anything for the KH value. How much to add per given amount of water?

2. Looking at my bubble counter and with a given KH thier seems to be a realsionship to ppm of CO2 in the tank by reading posts on here. Can someone explain this to me. Using the Red Sea test kit even without CO2 running my CO2 always measures 60ppm in the tank. This is with and with out CO2 hooked up. With a lot of agitation and with no agitation. Can't seem to get it to change so don't believe it at all.

So given 1 degree KH and 6.2 pH with a bubble count of 4 per minute to the diffuser what kind of CO2 value do I really have in my tank.
 

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You can use baking soda. It will also raise the pH as the kH and pH go hand in hand. Dosing directions can be found in my Guide.

Bubble rate is meaningless. You can't figure your CO2 levels based on kH and bubble rate.

There are alternate methods to determine your CO2 levels. If the pH in your tank is say 6.5 with no CO2 injected in the past 12-24 hours then taking the pH down one full point will give you 30 ppm.

If you are not injecting CO2 your CO2 levels will be about 2-3 ppm. You must have some other buffer present in the tank. Peat and/or driftwood are two common causes of this.

It doesn't surprise me that RO Right doesn't affect the kH as it's intended to raise the gH.
 

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Jason, I see this was your first post! Welcome to the forum. I suggest reading Rex's guide for a good primer on planted tanks to get you up to speed. The Red Seas CO2 checker will work fine for you if you don't use tank water in it. Instead, use distilled water, to which you have added just enough baking soda to get a KH of 4 dKH - that is a very, very small amount. The best way to get to 4 dKH is to first mix a tiny bit of soda in some distilled water, then dilute it with at least twice as much distilled water and check the KH. It will likely be very high, but by continuing to dilute it with more distilled water you can finally get down to 4 dKH. Now add some of that to the Red Seas unit and add a couple of drops of pH reagent to get the color a strong enough blue to easily see it. This solution will turn green when you have 30 ppm of CO2 in the tank water.
 

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Discussion Starter · #4 ·
How would drift wood affect this? Yes I have two huge pieces. My pH has been dead stable regardless of the bubble rate. But I don't know what the heck is going on with my test kit everything I check with it reads 60ppm.

How do you test for CO2 levels?
 

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Discussion Starter · #5 ·
Jason, I see this was your first post! Welcome to the forum. I suggest reading Rex's guide for a good primer on planted tanks to get you up to speed. The Red Seas CO2 checker will work fine for you if you don't use tank water in it. Instead, use distilled water, to which you have added just enough baking soda to get a KH of 4 dKH - that is a very, very small amount. The best way to get to 4 dKH is to first mix a tiny bit of soda in some distilled water, then dilute it with at least twice as much distilled water and check the KH. It will likely be very high, but by continuing to dilute it with more distilled water you can finally get down to 4 dKH. Now add some of that to the Red Seas unit and add a couple of drops of pH reagent to get the color a strong enough blue to easily see it. This solution will turn green when you have 30 ppm of CO2 in the tank water.
Red Sea is a liquid reagent titration kit to which you add 10ml of tank water. Then there is an A solution and titrate with a B solution. So I don't understand about using DI at 4KH in it. Have a bit of a chemical background and just want to get CO2 right in the tank.
 

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Hoppy was talkin about the Red Sea Co2 indicator, not a test kit....All you put in it is 1ml of distilled water with a kh of 4 degrees and add three drops of reagent to it, Then you put in your tank. It will show a green color when you have 30 ppm of Co2...You can find it at BigAlsonline.com....Oh and Welcome to the Planted Tank!
 

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Driftwood can leach tannic acid into the aquarium. This acid will lower the pH.

Have you tried more than one pH test kit?
 
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