Adding fish to a tank with CO2. Advice pls

[Ajm200]

Just added 4 fish extra to my tank after spending an hour slowly acclimatising them, gradually replacing the water they were in before netting them and releasing them. Now they are gasping at the surface.

The drop checker is green rather than yellow and the other inhabitants of the tank seem ok. I've added an airstone and started a 50% water change to reduce CO2 levels.

The CO2 had been off for 3 hours before I attempted to add them and they were fine in the other low tech tank

Is this normal in a tank with CO2? The other fish were added after a 50% water change and did not behave like this

 

[Ajm200]

Is there anything extra I can do to avoid this next time?

Been keeping fish for years but using pressurised CO2 is new

 

[Dolly Sprint 16v]

Just added 4 fish extra to my tank after spending an hour slowly acclimatising them, gradually replacing the water they were in before netting them and releasing them. Now they are gasping at the surface.

The drop checker is green rather than yellow and the other inhabitants of the tank seem ok. I've added an airstone and started a 50% water change to reduce CO2 levels.

The CO2 had been off for 3 hours before I attempted to add them and they were fine in the other low tech tank

Is this normal in a tank with CO2? The other fish were added after a 50% water change and did not behave like this

Amanda

Quick question /answer - spent hours slowly adding existing tank water to acclimatise them before netting them - they could have become stressed out being caught once before in the shop and you have caught them again - I think is was your problem. When I have puchased new fish I turn off the lights, place the plastic bag into the tank and slowly add tank water to the water within the bag / fish, then after 30 mins the bag is usually 3/4 full so I turn the bag on its side opening the top and allow the fish to swim out under their own steam, some times they dont come out by themselves and one or two of my platties swim into the bag that usually flushes them out.

Cannot see that the Co2 has caused an issue as there is a limited amount of gas within the water column (green dc) - not as if it was maxed out (yellow dc).
Regards
paul.

 

[Ajm200]

Maybe it was just a stress reaction.

I tend to net the fish out of the bag as I'm reluctant to add fish shop water to my tank. Didn't need to worry this time ad I was moving them from one tank to another but did it out of habit.

 

[Dolly Sprint 16v]

Amanda

If you look at it this way - for the amount of water within the bag is a drop in the ocean compared with your tank.

I would imagine a very slight difference the LFS and your water and I would expect a bigger difference between regional water eg. North West Water v Anglian Water.

Regards
Paul.

 

[ceg4048]

Just added 4 fish extra to my tank after spending an hour slowly acclimatising them, gradually replacing the water they were in before netting them and releasing them. Now they are gasping at the surface.

The drop checker is green rather than yellow and the other inhabitants of the tank seem ok. I've added an airstone and started a 50% water change to reduce CO2 levels.

The CO2 had been off for 3 hours before I attempted to add them and they were fine in the other low tech tank

Is this normal in a tank with CO2? The other fish were added after a 50% water change and did not behave like this

Unfortunately, yes. The fish that are already in the tank are accustomed to the higher CO2 levels, whereas the new fish are not. Here's a trick I use all the time. When you get new fish, don't release them into the tank. Let the bag float overnight and turn the lighting down to lower the stress. Overnight, the CO2 that the fish are exhaling builds up slowly in the bag. Release them the following morning prior to the CO2 being turned on. The CO2 in the tank is at it's lowest at that point, while the CO2 in the bag is at its highest. This helps them to deal with the rise in CO2 as the gas turns on and the concentration level builds. As the CO2 in the bag rises the pH drops, mitigating any toxic effects of NH4 buildup in the bag water.

Cheers,

 

[Ajm200]

Amanda

If you look at it this way - for the amount of water within the bag is a drop in the ocean compared with your tank.

I would imagine a very slight difference the LFS and your water and I would expect a bigger difference between regional water eg. North West Water v Anglian Water.

Regards
Paul.

I'm not to worried about minor differences in water chemistry just want to reduce the amount of water in case of water bourne parasites like whitespot.

 

[Ajm200]

Thanks Clive. I'll try to stick to addind fish on water change day and try your method.