Good news, and a question about CO2!

[rorie87]

First off, i am pleased to say that when i showed a video of my discus to the breeder (i was worried!) he informed me that they were breeding!!!! 4 days into a new tank and breeding already!! So happy!

BUT, he then mentioned CO2 and told me its a big no no for a discus tank. He said it could kill discus over time.

He was not sure 100% if this was just down to accidents by people, or if CO2 has a bad effect on discus that it does not have on other fish.... can anybody shed some light on this?

In the mean time i have switched off my CO2

[ericatdallas]

Hmmm turning off your CO2 for a little while hurt your plants too much. Probably best to move the fry to a BB tank for growout ASAP.

No comment about the CO2 hurting Discus... a high concentration of CO2 will hurt any animal. If you're properly dosing though, there should be plenty of O2 in your water for the Discus to use.

[rorie87]

No fry yet. Only got the discus 4 days ago haha. I just got a breeding tank though, so maybe after a while if they pair off, i may give it a try.

CO2 in high doses will kill off all my fish anyway. I think the suggestion was that discus are more easily harmed by CO2, or dont appreciate it at all?!

[DerekFF]

im sure some expert will hop in here, but as far as im aware of discus arent any more susceptible to CO2 than any other fish, and ive yet to hear anything about CO2 in regulated amounts harming anything

[Harriett]

Discus don't have trouble with CO2 injected water [planted tank]. It lowers pH and they do well in somewhat lower pH levels [like in the mid or high 6s]. You need a steady state of CO2 injection, that's the take home msg. The danger part is that if you put a system together that can allow CO2 swings, you take a chance that at some point, you will poison fish--so best to have a controller on the CO2 system for protection that keeps it steady. When a tank of CO2 is nearing empty and there is no controller, you can have what is called a 'CO2 dump' where a whole lot of gas dumps into the tank suddenly then it poisons all the fish in there. Do some research on injected CO2 systems!
Best regards,
Harriett

[jcardona1]

so best to have a controller on the CO2 system for protection that keeps it steady. When a tank of CO2 is nearing empty and there is no controller, you can have what is called a 'CO2 dump' where a whole lot of gas dumps into the tank suddenly then it poisons all the fish in there

A controller won't prevent end of tank dump. The only way to prevent that is with a dual-stage regulator and/or a really really good needle valve, like Ideal or Swagelok brands. Besides, I've never experienced this co2 dump, even though I've let my gas pressure get very very low.

[jimg]

Discus don't have trouble with CO2 injected water [planted tank]. It lowers pH and they do well in somewhat lower pH levels [like in the mid or high 6s]. You need a steady state of CO2 injection, that's the take home msg. The danger part is that if you put a system together that can allow CO2 swings, you take a chance that at some point, you will poison fish--so best to have a controller on the CO2 system for protection that keeps it steady. When a tank of CO2 is nearing empty and there is no controller, you can have what is called a 'CO2 dump' where a whole lot of gas dumps into the tank suddenly then it poisons all the fish in there. Do some research on injected CO2 systems!
Best regards,
Harriett

+1
I have never had problems with co2 effecting discus either except when I did not have a controller and it did dump and almost killed everything. A controller completely shuts the co2 off when it reaches a set level. I used dual stage regulators with decent needle valve also and you would think the needle valve would hold steady, but mine didn't

[White Worm]

The needle valve doesnt allow any dump and I have not seen anything like this happen. I let it run empty each time. Wont hurt the discus at planted tank levels. Since it would not all disolve, shouldnt be a problem anyway.

[jimg]

mine dumped and ph was in the low 5's in a few hours when normally it was kept at 7.2
another time I saw fish dark checked ph found it low checked tank it was almost empty. So I know they can dump, it happened to me. but i also used to set bps pretty high due to trickle filter so may have been combo. bps are set according to outlet pressure you set, then you set the needle valve according to that pressure. When that pressure changes,low volume, it changes the pressure on the needle valve too.

[rorie87]

Good stuff, thanks for the replies! My PH has been at 6.3 from the very start - partly CO2 and partly the special substrate i have in.

So thanks very much for reassuring me