Co2 Injection

[srolfe]

36G Bowfront
Magnum 350 Filter
Automatic CO2 Injection
17 Tetras
5 Corys
KH=8
GH=8
PH=8.5

This week i installed the co2 injection, the salesman said that the bubble counter was not needed. I set the system to PH=6.8 and turned it on. I later noticed that large amounts of co2 were being added, causing fish distress, I turned the system off for the night. Next morning the PH had risen to 8.5. I installed the bubble counter and adjusted to 1 bubble/sec. Waited for day and co2 did not go down. Raised rate on bubble count and again streesed fish. Turned rate back to 1 bubble/sec. Will PH go down or what should I expect?

 

[houndour]

Which piece of CO2 kit do you have?

Sounds like you have a pH probe controller thingy. I don't have one of these so don't know how they work. Sounds like its reading your pH of 8.5 and then shooting out the CO2 at a fast rate to get to 6.8. Going from 8.5 to 6.8 in a short time would be a danger to your fish.

I would set the probe to say 8.3 the first day and then just lower it each day so that the pH drops gradually over a week or so.

 

[srolfe]

Yes, the system has a PH sensor. The adjustment on the needle valve is very senisitive.

 

[SkiFletch]

might want to ask this question in the planted tank section, get more responses there

 

[@ombomb]

I have just set my system up and am using the JBL pH controller.

Did you calibrate the probe correctly before setting it up?

As houndour has said, a rapid change in CO² = a rapid change in the pH = unhappy, unhealthy fish.

You need to work out your target pH, based on the KH of your water, ideally aiming for 30ppm of CO².

Once you have worked out what the pH level should be to achieved that correct level of CO² the process should be a gradually one. Personally I brought the target pH of mine down 0.1 - 0.2 every 12 hours. I would recommend that you keep an eye on the speed of the bubbles being released (are you using a defuser?) and aim for a steady flow and longer periods on rather than short bursts of lots of bubbles.

 

[littleimp]

I have just set my system up and am using the JBL pH controller.

Did you calibrate the probe correctly before setting it up?

As houndour has said, a rapid change in CO² = a rapid change in the pH = unhappy, unhealthy fish.

You need to work out your target pH, based on the KH of your water, ideally aiming for 30ppm of CO².

Once you have worked out what the pH level should be to achieved that correct level of CO² the process should be a gradually one. Personally I brought the target pH of mine down 0.1 - 0.2 every 12 hours. I would recommend that you keep an eye on the speed of the bubbles being released (are you using a defuser?) and aim for a steady flow and longer periods on rather than short bursts of lots of bubbles.

Did you calibrate the PH sensor?? It should have come with a chemical collection which you use to calibrate the probe?? Also this has to be done on a regular basis as it drifts from the correct setting as time passes.

Your sensor is probably reading too high?
Does it have a digital display showing the PH??
If so does this match your tank?

I would recommend you do a 50% water change to bring the levels cloe to noraml & start again, gradually.

If this had a been a marine tank you'd be scraping bits of calcim of your tank & fittings for weeks!! Not to mention bagging up dead fish & propbly live rock (£10/kg!!!!!!!, 25kg neede in a36g!!! £360!!!!!)

 

[srolfe]

Yes, I did calibrate the sensor. I am not using a diffuser. The PH is still not dropping but seems to have stabilized at 8.7. I am turning the co2 off at night.

 

[houndour]

You need something to allow efficient diffusion of CO2. In most peoples cases this is a ladder of somesort that simply keeps the bubbles in the water for longer.

With the DIY Hagen nutrafin kit you get a ladder: http/www.drsfostersmith.com/product/prod...3779+2146962593

With the JBL Profi sets you get a spiral ladder: http/cgi.ebay.co.uk/JBL-Proflora-Co2-Dif...1QQcmdZViewItem

If you do not have anything like this I would recommend getting something like that.