The Puffer Forum

I'm in the process of setting up a 55 gallon DP community that will hopefully house 10-12 DPs and maybe 6-8 khuli loaches. The tank will be heavily planted with live plants and well lit, which will likely require CO2 injection. From what I've read, CO2 injection can have quite an effect on pH.

My question is: does anyone here do CO2 injection on their planted tank, and if so, what do you do to sufficiently buffer the water so that you don't have major pH fluctuations?

Thanks for any help.

Andy

The pH drop from CO2 gas supplement is how you measure the CO2 concentration in the tank, using the pH/KH/CO2 tables such as the one at:

http://www.sfbaaps.com/reference/table_01.shtml

The fish do not "read" pH, they read TDS (total dissolved solids) and particular ions in the water. Dissolved CO2 has no effect on the TDS, and so long as the CO2 is at or below 30 ppm, no significant effect on the fish. For more detail, see "What? The Water is Hard?" in the Library on this site:

http://www.thepufferforum.org/viewtopic.php?t=416

HTH

Ok, just to make sure I have this right:

These numbers are hypothetical, pulled from the chart, just to make sure I understand the concept.

Let's assume that my tap water straight from the tap has a pH of 7.6 and KH of 5. This would mean that the level of disolved CO2 is 3.7ppm. I then being CO2 injection, which drops my pH to 7.0. Would my KH remain at 5, meaning the level of disolved CO2 would be 14.7ppm, or would my KH drop as well?

If KH does remain stable, the fish in the tank should suffer no ill effects from the drop in pH as the TDS should remain the same?

Thanks for your help.
Andy

The KH should remain roughly constant.

Over time the KH will usually gradually decrease quite slowly -- but in this case it would probably be replenished with water changes before you noticed it.

Won't Kuhli's be eaten by the DPs? I know they're fast/reclusive, but they must look like tasty wriggly worms to a puffer!

Back when I participated in the DP forum, there were trials of that pairing. Some okay, others not. I have not kept up with that area, so don't know how the tally is going.

You have the idea. It is another great myth area, so congratulate yourself.

Jhong wrote:Won't Kuhli's be eaten by the DPs? I know they're fast/reclusive, but they must look like tasty wriggly worms to a puffer!

I've read that there have been people whom have had success with this pairing, so I wanted to give it a try. I figured that having a heavily planted tank with a sand substrate should help matters.

Something to consider for the sake of the kuhlies if you do try it, I siliconed/epoxied together a "pile" of river rocks loosely. There are lots of gaps for the kuhlis to go in and out of and not a whole heck of a lot can get in there other than them. And because its all one big attached piece, I can pick it up to vaccuum underneath, and don't have to worry about anythign shifting and falling in on the kuhlies while they are underneath. I don't have any puffers with mine, but its an idea to give them a safe place to hide in. Most of the time they are in there, and come out at feeding times, then go back into either a hunk of java moss or the rock pile.

I actually have a khuli loach in with my DPs. He spends most of his time hiding in the thick java ferns on a piece of driftwood, but comes out for food and at night. He's gotten fat and healthy and has never had a nipped fin, at least that I have noticed. I can go a week without seeing this bloke since the plants in this tank have gotten so thick... even though I usually prune out huge amounts of plant stuff every water change.

I also have otos, amano shrimp, a SAE, and 8 DPs (6 female, 2 male).

This DP tank is a 29gal with a 65W compact light and an AC 200, and I use the yeast and sugar stuff mix CO2 (I get the pre-packaged stuff because it saves me time). I have not had a problem with PH drops as long as I keep up on my water changes... if I slack then I can see it slowly drop. I add no buffers, but just use the hard tap water we have in SoCal. I do add a liquid fertilizer once every two weeks, but thats it.

Also, the good Dr. Ebert does not mention the ph range for DPs, so I'd aim for steady as opposed to a specific number... something between 6.8 and 8 is what I like for my freshwater tanks. RTR is the person to ask about this however.

Technically, the best info we have is pH 7.5-8.3, but that is native water, so by water KH with no consideration of CO2 supplement.