CO2, Aquasoil, and Low pH

[DGalt]

Hopefully I'm nearing the end of my battle with aquasoil. Tank is planted, water is clear, ammonia levels are almost 0. Last thing is CO2 and pH and then I can actually put some fish in the tank

I have a pressurized CO2 system whose CO2 line is fed into a Rio 180 (with modified impeller, as per Tom's needle wheel DIY thread). I had this system before I made the switch to aquasoil and my pH had been around 7 if I remember correctly. Before the switch I was using a different underwater filter as my CO2 diffuser (or whatever it's called) that was a bit less efficient, I think, than the modified Rio.

My pH has dropped rather significantly, though, since the changes mentioned above. Right now it's at a maximum of 6 (my pH kit doesn't go below 6, going to get some test strips from my lab tomorrow; unfortunately I don't think the grad students would appreciate me taking the pH probe). I don't really know what my CO2 levels are (I changed the solution in my drop checker but it hasn't really changed colors). My kH is 5 degrees (86ppm).

A pH of 6 and especially below 6 isn't going to work though. Could use some suggestions about what I could try.

Oh, this is on a 15 gallon. That's probably important.

thanks

 

[VaughnH]

Hopefully I'm nearing the end of my battle with aquasoil. Tank is planted, water is clear, ammonia levels are almost 0. Last thing is CO2 and pH and then I can actually put some fish in the tank

I have a pressurized CO2 system whose CO2 line is fed into a Rio 180 (with modified impeller, as per Tom's needle wheel DIY thread). I had this system before I made the switch to aquasoil and my pH had been around 7 if I remember correctly. Before the switch I was using a different underwater filter as my CO2 diffuser (or whatever it's called) that was a bit less efficient, I think, than the modified Rio.

My pH has dropped rather significantly, though, since the changes mentioned above. Right now it's at a maximum of 6 (my pH kit doesn't go below 6, going to get some test strips from my lab tomorrow; unfortunately I don't think the grad students would appreciate me taking the pH probe). I don't really know what my CO2 levels are (I changed the solution in my drop checker but it hasn't really changed colors). My kH is 5 degrees (86ppm).

A pH of 6 and especially below 6 isn't going to work though. Could use some suggestions about what I could try.

Oh, this is on a 15 gallon. That's probably important.

thanks

Why do you think the pH below 6 will be a problem? We have found that pH changes caused by CO2 are not a concern. In fact it isn't possible in our aquariums for the pH to drop too low from CO2 injection. Long before that could happen the fish would all be killed by the high CO2 concentration. Also, as I recall, CO2 can only lower the pH to around 5.5, before it stops dissolving into the water. Even that isn't too low for the fish or plants.

 

[DGalt]

Forgot I posted this.

The main reason I'm concerned is that I keep both shrimp and snails. From my understanding, an acidic pH (and especially one at or below 6) is going to be detrimental to their shells.

If that's not a valid concern then great, but if it is something that I should be worried about what are my options in terms of increasing the pH?

 

[VaughnH]

You can increase the pH by increasing the KH. And, that can be done with baking soda, or with carbonate rocks, such as crushed coral or dolomite or limestone. If you want some very decorative rocks in the tank, you can get Texas Holey Rock, or some equivalent, which is carbonate based rock, with water melted holes in it. Doing that raises the KH and pH, but you then also need to do regular water changes to keep the KH from rising too high.