Adding A Lot Of Fish

[hwoarangtag]

Say my tank is cycled but currently has only <10 fishes. (in a 75 gal) Is it advisable to add a lot of fishes say 30 cardinals at one shot. What will be the consequence?

 

[benniebru]

if u add a bunch of fish at first u might notice a spike in ur amm and nit because ur bactieria needs to catch up thats y if u add 30 fish i would at least break it up into 2 sets 15 wait like 3 or 4 days then 15 more

 

[hwoarangtag]

aww, the problem is they wont sell cheap unless you buy say 30+ or 20+ fishes

 

[evilchild]

aww, the problem is they wont sell cheap unless you buy say 30+ or 20+ fishes

if you get a big spike you could lose the lot?

 

[hwoarangtag]

There must be a way to prepare your tank before hand. Can i add say some ammonia a week prior the entries of the new fishes?

 

[zukimoo]

Around here they will sell and hold the fish. They won't guarantee the fish left at the store but I've never had a problem. I'd had it happen that I'd see a nice fish only to come back and it was gone. Now I buy the fish, go home and set-up a hospital tank and then go back the next day. They might just do this for me because I'm always there but it does save alot of stress.

One local shop is holding a xmas present until the week before when my daughter is going to be gone.

 

[Squidman]

You'll probably have a huge increase on the ammonia. nitrate, nitrite levels if you add tons of fish at once. I say to add small groups every week or so until the tank is not too over stocked but stocked to how you like.

 

[PRW1988]

Generally what ends up happening when you try to add too many fish at once is that, as said, a nitrite, nitrate and ammonia spike(s) occur. This is because the bacterial cultrue is not yet matured enough to handle this many fish just like that *snap*, if you have any spare tanks (say a couple 10 gallons) you could do a 20gallon water change on the 75gallon tank (use the 20gallons to fill up the 2 10's -use some matured filter media aswell), then set up the 2 10gallon tanks and wait for about a week or so adding about 5 Cardinals ever 2-3 days. This should atleast allow the tank to catch up and you should be ok.

 

[hwoarangtag]

or better, can i just put all my fishes now in a 20 gal. Then force my 75 gal to go on a fishless cycle by putting ammonia to ~5 ppm and until it settles. Then 80 % water change and reput every fish in there. I suspect this mini fishless cycle will be shorter as my filter media already has some bacteria.

 

[benniebru]

or better, can i just put all my fishes now in a 20 gal. Then force my 75 gal to go on a fishless cycle by putting ammonia to ~5 ppm and until it settles. Then 80 % water change and reput every fish in there. I suspect this mini fishless cycle will be shorter as my filter media already has some bacteria.

even with a fully cycled tank u still cannot but that big of a bio load into a tank that fast the bacteria will need time to multiply and catch up
there is no ways around it u have to do small amounts at a time over a period of time u can go ahead and add all those fish at once but u will be just burning ur money cuz u will have some fish loss with the increase in ammonia and nitrites