Hi everyone,

I'm a newbie here. *waves* I've got some questions now that I've started a CO2 injection system for my 10 gal planted tank.

I basically have a packet of baking yeast going to town on some carbs in an ocean spray bottle behind the tank, with a second bottle functioning as a gas trap.

First of all, I'm concerned that I may put too much CO2 in the tank. I don't have a good way to measure the amount of CO2 because I don't have a good test for exactly how hard my water is. (It's very hard). What are the warning signs for too much CO2 in the tank?

Which brings me to, does anyone have a good water hardness test kit?

And what should an ideal bubble rate be for my little fermenter?

I have a 10 gal, cycled tank with two large bunches of anacharis, one large hornwort, a java lace fern, two moss balls, and a clump of mondo grass.

It is home to three platys, one corycat, and an apple snail.

It started at 8.4 pH and is down to 7.0 at last reading.

Any advice/tips?

Chessie

Welcome to the site!

I would be very surprised if a single bottle DIY ever came close to harming fish with too much CO2, even with a 10g. If you don't have a warm feeling about it, just add a bubbler that comes on when your light goes out. The plants will not use the CO2 when the light is out and the surface disturbance that comes from the bubbler, will cause the CO2 to vacate your water. Adding the CO2 will lower your ph.

I would look for a gh test kit. This is the hardnes of the water. API makes a gh/kh combined test.

Thanks, I do have a bubbler. I turned it down so there isn't too much surface disturbance. I'll turn it back up at night.

Chessie

If you leave it on at the same time, you are loosing a lot of the CO2 you're putting in. If you want maximum affect from the CO2, that is.

That brings me to my next question. Does the pH "bottom out" and stay steady? The biggest concern I have with the CO2 is that I'll go from having a tank that had a crazy high pH to a crazy low pH. My water is from a well so it isn't buffered.

So far, my tank has dropped down to 7.0-7.3 ish from 8.4-8.6. I know that CO2 must be getting into the water or I wouldn't have my pH down so much.

During the day, I have the bubbles turned way down so they don't disturb the surface very much at all. They are bubbling at pretty much the same intensity as the CO2 bubbles. But if I don't want the tank to swing too low, should I make a habit of turning the bubbles up while the plants are breathing O2 at night?

Chessie

The ph should continue to drop as long as the CO2 content continues to rise in your tank. This should not hurt your fish as it is a natural rise and fall. If you have well water and your ph is that high, you have plenty of buffers in your water. It wouldn't hurt to turn up the bubbles when your light goes out.