CO2 tank transition to non CO2

A non-CO2 tank needs less light than a CO2 tank. Actually, CO2 is effective in low light tanks too, but usually people who use pressurized CO2 also have high light intensity. Using high light intensity and no CO2 is an open door policy towards algae. So, if you stop dosing CO2, and have high light intensity, you should also reduce the light intensity at the same time.

 

I have a low light tank that I was doing diy co2 on. It was growing great but I had so many issues with the diy that I decided to go with non-co2. My hygrophila started losing leaves within a couple of days. I went for a whole 4 weeks and still I was scooping out a net of hygro leaves daily. Finally I went back to diy co2 because scooping out dead leaves was becoming more maintenance than the diy, and the plants are once again growing great. Perhaps eventually once new growth had come in the leaf shedding would have stopped, or maybe if I had reduced lighting it would have helped, but I was already at low light to start with so that wasn't really an option. I also had anubias and java ferns in the tank which didn't show many issues other than no growth. Algae was also a bit of a problem especially at first, I went from 0 algae to scraping the glass weekly.

 

On the other hand, I recently took some clippings of hygro from my co2 tank and put them into another non-co2 tank. So far they have not died or developed deficiencies, it's been a few days. On the other hand they are not really growing either. So I guess it's a bit hard to say exactly what will happen in any particular setup. Perhaps cutting back gradually would work better than cold turkey.

 

To answer your question about the transition period- from my quite limited experience, they do suffer a little. More so the higher-light loving plants like ambulia (at least it always melted for me).
I stopped adding DIY C02 to a tank that has cardamine lyrata, hornwort, java moss, ferns and water sprite.

• Initially the sprite died back a little, but then adjusted and started to put out differently shaped leaves. Older leaves with this new growth die back sooner but it always puts out shoots. Still looks good!
• Hornwort, after about a month, really looks LUSH and bright green, very thick stemmed. Looks much better than fine delicate growth from before.
• Ferns arent growing from what I can see.
• Moss grows very bright green and lushly but is infested with hair algae atm.
• Cardamine's still growing good but slower, with disintegrating bottom leaves.

Hope that helps