# Rainbow fish and co2



## Ajm200 (7 Jun 2010)

Hi,

Do rainbow fish have a lower tolerance to co2 than other species?

I have recently added a pair of bosemanni rainbows to my high tech tank and have had to move them back to the quarantine tank as they seem unable to cope with the co2 levels.

They were added when the co2 levels were very low after a 70% water change.  Within half an hour of the co2 coming on in the morning they were gasping at the surface even though the other fish were fine and the dc was barely green.  Turned the co2 off and they recovered after an hour but the dc was blue.

Turned the co2 rate right down and tried again today but shortly after the dc was green they started gasping again so I've moved them out to the other tank

The other fish show no signs of distress.

I'm wondering if this is normal with rainbowfish or if these have a problem such as gill damage.

Would appreciate advice, thanks


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## LondonDragon (7 Jun 2010)

That was one of the reasons I got rid of my Bosemani Rainbows, I now have Threadfin Rainbows that tolerate much higher levels.


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## Nick16 (7 Jun 2010)

my lake kutubus seem to struggle a bit. but they are fine at the moment seeing as my Tetratec filter decided to break and take my co2 with it. 

im liquid dosing at the mo and they seem fine with that....


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## Ajm200 (7 Jun 2010)

Thanks for that.  Might have to rehome them as I don't think a 90l tank will be big enough for them long term and I don't want to see them struggle in the big tank.


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## sanj (8 Jun 2010)

Hi, 

I keep several species of Rainbows including Boesmani and yes some are more susceptible than others. However in the day I have no problems. I did have a massive wipe in summer 2006 which killed my hobby for 2 years. This was down to hot weather and oxygen starvation principly overnight when the plants arent producing O2. Since then I have an air pump that comes on at 01:00 to 12:00 when lights and CO2 are off. I have not had a problem since.

I would agree a 90l is far to small for Boesmani or any of the larger rainbows. i would stick to Blue-eyes (Pseudomugils) and the Thread fins as mentioned.

Adult Boesmani and Kutubu or any rainbows that size need to be in a few hundred litres minimum for adults imo.


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## Ajm200 (9 Jun 2010)

Originally I intended to keep them in 500l+ but can't see them suffer with the co2.


Anyone know how dwarf neon rainbows cope with co2?  Might give these a try if someone has kept them successfully in a hugh tech tank.  Hubby is talking about getting 8 of them.


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## Garuf (9 Jun 2010)

If you reduce the light then you'll need less co2 and the rainbows will be happier. Rainbows, the bigger ones at least are from pretty hard water so keeping them in soft water further exacerbates the issue.


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## sanj (14 Jun 2010)

Ajm200 said:
			
		

> Originally I intended to keep them in 500l+ but can't see them suffer with the co2.
> 
> 
> Anyone know how dwarf neon rainbows cope with co2?  Might give these a try if someone has kept them successfully in a hugh tech tank.  Hubby is talking about getting 8 of them.




500l is not a problem, but i would for caution run a o2 pump over night. 

It think Boesmanii in a 90 litre were half the problem when you consider how much 02 could be dissolved in the water.

My 860 litre 70 odd fish, not all rainbows, but a dozen each Boesmani,Kutubu,aswell as smaller groups of other rainbows. Currenly they are all living together in 400 litre waiting for my new tank.

Neon Rainbows... they have more an issue with water quality and in my experiance are more susceptible to mycobacteriosis (the main killer of Aquarium fish). Look out for rainbows that have sores on their body whether they are fresh or healed over, dont buy from those sources. They may recover, but alot dont.


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