How Many Cories Should I Add To The Tank At Once?

[ey2006]

I've done some research on Corys and think I am going to go with either the Bronze/Albino or the Peppered Corys...I am planning to get a group (3 to 5) for my 29g tank.

The question is, how many Corys should I add in one go? I don't want to be adding too many as to cause a mini-cycle or stress out the fish. Would it be optimal to add 3 corys this weekend and another 3 in 7 days?

Also, is this the correct method of adding new fish to a tank:

Float the bag in the tank for 20 minutes, then add tank water to the bag and continue floating for 20 minutes, before introducing the new fish into the tank.

Many thanks.

 

[neon_platy]

i shouldn't reply as im so bad...i'd do all at once, but actually the way i did it was in intervals of 3 so i think you've got hte right idea same with the bag, im really bad about that, my cories have survived it and haven't been sick, but i think you're about right maybe not 20 minutes, that seems excessive to me but maybe about that then adding the tank water in the bag then releasing them they're so much fun to watch when they get out in the tank have fun!

 

[Fishkeeper2004]

You can add corys 6 at a time, but then leave 7-14 days gap before you add anymore fish.

 

[Tempestuousfury]

I take it that it is a cycled tank, but are there any other fish in it? If not, I think 6 at once should not be too bad, provided that they are the only fish you add.

As for adding water to the bag while letting the temp acclimate, I am told that acclimating the fish to the new water quality takes days, so it is an ineffective practise. If this is true, then all you really do is stress out the fish by opening up the bags, adding water, and closing them.

 

[love_fish]

A good acclimation method is to flost the bag, and every 5 minutes, add a cup of tank water. Do that for 4 or 5 times and you'll be good.

 

[jollysue]

When acclimating fish, it is good to take into account several items. Have they been acclimated to your local water, such as at your lfs? If they have been shipped or bought at a locale with different water, a longer period should be taken to acclimate.

The optimal acclimation: Turn the tank lights off and dim the room lights. Open the bag to get fresh air to them, (I then pour them into a hanging hospital tank, as I am very clumsy with the bags), float them in the container in their original water for 20 minutes to get the temperatures equal. When the temps are equal add a little tank water every 4 minutes or so. Just add small amounts of water frequently. Pour out half the water when the container gets full. Repeat the proceedure 3 or 4 times until the water in the container is the same as your tank water. Never add the bag water to the tank. When the water in the bag is the same as the tank, pour them into the net over a bucket and add them to the tank. Sometimes I add the water until the water in the holding tank is completely changed, then I can just let them swim out into the tank. I don't like to net cories because their spines and barbells sometimes get caught. Keep the lights off for many hours or the day.

Shock is caused by sudden changes in water parameters like temperature, ph, etc., and rough handling. These water parameters can be different even than your lfs because of the additives either of you may use.

When I am acclimating shipped fish in medicated water, it takes several hours even an afternoon. They have been in the same water for days and been in stressful conditions, banged and bounced around. They need to get extra consideration. The more stress the fish get the more chance that they will get sick or fail to thrive.

When buying fish at my lfs, I often ask how long they have had them. If they have had them a couple of weeks without a problem, I am more reassured that they are acclimated to the local water and not deseased.