CO2 & pH Fluctuations

[TW]

Hi there

I'm a newby to Discus, but have a planted tank for around a year now with pressurised C02. The C02 keeps my usually high pH (7.5 or above) down at the target of 6.5.

I check my C02 bottle is running morning & night, but it usually runs out when I am at work. I have 2 spare bottles, which I keep filled so once I know one is empty, I can change to a full one quickly. But if it runs out while I am at work, the pH will steadily rise until I get home. I will make sure I am extra diligent checking the C02 - but what will this do to my discus if it spends nearly a whole working day at the higher pH.

The guage on my regulator doesn't really tell me when it's running out. It stays at full & only shows "empty" when it has run out.

Thanks in advance.

[Erk]

Hey TankWatcher I am a newbie as well, and I have actually only had my pressurized system setup for a lil over a week now, and I do lots of research about all this fish stuff in general, and I found this link from plantgeek.com. Sounds like the pH is supposed to fluctuate like that. My tank goes from 7.0 without co2 to about 6.4 with co2 during the day, and I run a bubble wand when the lights go off just for some added safety. Just try to make sure you have a fairly high kH value in your aquarium, and the fluctuations shouldnt be a problem

http://www.theplantedtankfaq.com/CO2_FAQ.html

Its an interesting read. May or may not be correct info, but give it a read if you want, and hopefully in the meantime some of the more experienced co2 enthusiasts will chime in

Good luck with it all :D
Eric

[TW]

Thanks Erk for the reply :D

Yeah, I know that's what C02 does (lowers pH). Just wondering what effect it has on discus when pH rises due to an empty C02 tank. All the other fish in the tank are ok with higher pH, but I'm worried about them. I don't think there is anything really I can do about the spike, but thought I'd like to be forewarned of any likely problems it may cause.

I'm sure you will love have the presurrised C02. It's a lot less work than DIY systems.

Thanks for the link :D

[Greggy]

Captive-bred Discus seem quite tolerant of a high pH.

Currently my 8 Disus are living in pH that sits anywhere between 7.6 and 7.8 (sometimes even 8.0) as I've given up on trying to keep the pH down with buffers, and the tap water in my area is shocking (hard & alkaline).

With all the water changes I do its just easier to leave the pH as it is out of the tap and see how things cope. So far the Discus are just fine, but I must say my Cardinals hate it... one by one they are dropping off. Funnily enough my Rummy Nose's don't seem to mind it at all, and I thought they were more delicate than Cardinals!

Leaving the pH the same as the tap water also makes emergency water changes easier/quicker, not that any of us want to do these!

Regards,

Greggy

[Greggy]

But yes I should mention that fast pH swings are not going to be tolerated by Discus compared to a slow pH swing, and I don't really know how fast it will rise with the CO2 injection not running.

Hopefully all would be AOK.

Regards,

Greggy

[TW]

Thanks Greggy

I don't think it rises fast - but it does rise. I guess I can't do anything about, so I hope it will be okay.

Thanks for the advice.