What can go wrong with CO2 injection

[purplecatfish]

I'm thinking about investing in a CO2 set up but I'm wondering what are the potential problems? e.g. I've heard that if you run out of CO2 then the pH can crash. (One of the well known LFS had that happen and they lost all the fish in their demo tank.)

Also what are the must dos and definitely don'ts?

And if you weren't limited by money how would you set up a CO2 injection system? (i.e. no budget driven shortcuts.)

[alanmin4304]

Redwood Aquatics had a demo system controlledby a little computer and pH meter I think. I can't remember how much it was worth but it was not cheap. I noticed it was no longer being used last time I was there. I have known Bob Ward for a number of years and he is a very successful plant grower and tends to use more natural methods like adding more fish.

[SpidersWeb]

Running out of CO2 wont normally be a problem.

What can be a problem is making sure the CO2 switches off at night when the lights are off, or if your lighting fails. The plants dont use the CO2 when the lights are out, so it builds up to high levels, and the pH crashes down, often in to the 5s. A solenoid on a timer with the lights is normally the solution for this.

If you are using a hard water to raise pH, and using CO2 to lower it again, then running out of CO2 would be a problem as the system is reliant on it - but that would happen at night anyway when it all switches off.

[candy]

Im intrested on the whole turning the co2 off at night thing. what if you were using a small yeast fementing ( cant spell) system? should it be unpluged at night? or only if you are using gass?

[Faran]

The Weipro Digital CO2/pH Controller on TradeMe will control a solenoid via a pH meter and ensure that no crash or spike will ever happen. I am one of the unlucky few that have killed an entire tank of fish with CO2. Strongly recommend this as a precaution.

[Pegasus]

You have mail B&K

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Bill

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[alanmin4304]

It is probably a bit like most other things with fish keeping and depends on how much money you want to throw at it. I must be Scottish---I add fish

[SpidersWeb]

Im intrested on the whole turning the co2 off at night thing. what if you were using a small yeast fementing ( cant spell) system? should it be unpluged at night? or only if you are using gass?

Its more the amount your injecting and how. Bubbling wont do it, but if you're using a filter or diffuser that crushes the bubbles in to the water then you should have some facility to remove the excess CO2 (air bubble pump on at night) or stop putting it in (solenoid). A standard ladder type diffuser or air stone wont be able to get enough CO2 in to the water to cause a pH drop in most conditions (unless your water is very soft).

[purplecatfish]

I've already added more than enough fish . I'm just wondering about replacing the need for flourish excel.

Maybe I can convince the wife to let me splash out on a really good system if it'll pay for itself by saving on the excel :lol:

Honest it's an investment :lol:

[alanmin4304]

CO2 is no use without adequate fertilizer and light. Co2 gives plants carbon which is the building block of organic matter but phoshates and nitrates are also required to build proteins. Like most things in a fish tank it is a whole living system and one part cannot take place without the other. Just adding CO2 will not do much. Flourish excel is another way of your plants obtaining utilizable carbon so you may not need both (or you may not need either).

[purplecatfish]

I'm adding potassium sulphate (which I get from Stokers) on a daily basis. And I've got aqua basis and those JBL balls in the substrate (it's less than a year old). Also I'm probably going to start adding trace elements and epsom salts soon. As for light I've got 8 x 54w t5s on my 700L tank.

p.s. I've been involved in horticulticure for 25 years and I've got a botany degree.