How many fish to add at once???

Hi everyone, so I currently have set up a 75 gallon tank with two fancy goldfish in them. I want to go to the LFS to get some more goldfish but I was wondering how many goldfish I could safely add to the tank at once without overwhelming my cycle. I was thinking to just add 2 juvenile fancy goldfish. Any opinions would be helpful.

 

I know we have worked together on getting this tank cycled but please refresh my memory. How long has the tank been fully cycled? If you have been seeing 0 ammonia and nitrites for 2 or 3 weeks it should be safe to go ahead and add 2 more fish. Just keep a close eye on the numbers and be prepared to do water changes as needed. Once fully cycled it shouldn't take long for the bacteria to catch up with the higher bio-load.

 

Ok so long story short coz I just was super dumb with this whole thing. I had a cycled Fluval 307 on the old tank which had been set up since Xmas but forgot I could just put that on the new tank. When I added the established filter and 3ppm ammonia, the ammonia and nitrite both processed within 24 hours. I put in my two fancy goldfish, it’s been three days and both ammonia and nitrite are still at zero. They are pretty heavily fed. By the time I plan on adding the next two fish, it will probs be in a week anyways but I may go sooner, think it will be ok? I’m ok with doing water changes, luckily the tank is planted so the plants end up eating the majority of the nitrates anyways.

 

I wouldn't add more fish until these fish have been in this tank for at least 2 weeks. If you can wait that long you should know for sure the cycle in this tank is stable. I would want to know that for sure before adding more fish.

 

Ok Imma defo take that advice and see where it is in 2 weeks. I don’t wanna risk any fish lives! Thanks for ur help with everything since the start mattgirl !

 

Ok so long story short coz I just was super dumb with this whole thing. I had a cycled Fluval 307 on the old tank which had been set up since Xmas but forgot I could just put that on the new tank. When I added the established filter and 3ppm ammonia, the ammonia and nitrite both processed within 24 hours. I put in my two fancy goldfish, it’s been three days and both ammonia and nitrite are still at zero. They are pretty heavily fed. By the time I plan on adding the next two fish, it will probs be in a week anyways but I may go sooner, think it will be ok? I’m ok with doing water changes, luckily the tank is planted so the plants end up eating the majority of the nitrates anyways.

I have a very different view on this. Since your tank can handle 3ppm ammonia a day, you are good to add in a full bioload as soon as you like, even with heavy feeding. There should be no need to do water changes either.

Unless something went wrong or will go wrong along the line, there is no reason why your tank handling 3ppm ammonia/day can't handle a full stock.

 

I have a very different view on this. Since your tank can handle 3ppm ammonia a day, you are good to add in a full bioload as soon as you like, even with heavy feeding. There should be no need to do water changes either.

Unless something went wrong or will go wrong along the line, there is no reason why your tank handling 3ppm ammonia/day can't handle a full stock.

You are probably right but I always err on the side of caution. I would hate to give advice and it caused the death of a fish.

 

You are probably right but I always err on the side of caution. I would hate to give advice and it caused the death of a fish.

I would rather just give advice based on the evidence provided. But fair, to each their own way of giving advice.