How many Grow out tanks per pair?

[smallfin]

Hello

I'm planning on making a bit of a rack af tanks but wondering what breakup of sizes I should use. For example If I have 1 pair in a 18x18x18 how many different tanks and sizes would I need to grow out the babies through out a year. 3ft every couple of batches? Roughly how many batches would you get in a year?

At the moment thinking of a 6ft rack 3 tier made up of 4 18x18's at the top
then 2 x 3fts second teir and 2x3fts bottom teir but will that not be enough 3fts? or can I get away with 2 3fts and 1 6ft?

Any ideas from other breeders how many tanks they would end up using for 1 pair, that would be great.

Thanks
Smallfin

[jeff@zina.com]

There are a lot of variables to this, like are you parent raising and for how long? If you pull the eggs for artificial hatching, you could have 30 or more broods in a year. Parent raising you're looking at more like 6.

More mature pairs will usually have larger spawns, up to a point. You might have 30 survive to growout stage, you might have 300. How long are you raising them for? You can reach 2" size quickly and recycle the tank, or you could raise them to 4-6" and have them a year.

How frequently are you changing water? A 30 gallon tank could hold 15 juvies if you change the water weekly, 100 if the water is changed 3 times a day. A general rule of thumb is 2 gallons of tank space to raise them to 2" size. Shape of the tank can vary this a bit, and you can easily change this through water change frequency. But that might give you a start.

Of course, my general results are that, no matter how much tanks space you have, it's only about half what you need. :)

Jeff

[smallfin]

Thanks Jeff

Removing babies after about 4 weeks. approx 80-100 each time maybe.
changing water 50% a day at this stage.
planning to raise for about 12 months.

True about never having enough tanks. I think I'll make the rack and start from there and if I need to add more, make another one I guess.

how important is changing water 3 times a day v's once a day for fry?.

thanks

smallfin

[jeff@zina.com]

how important is changing water 3 times a day v's once a day for fry?

Water changes are not important at all. Water quality is. If it takes 3 changes a day to keep the water quality up, then it's very important. If it only takes one change a week, then changing the water three times a day is silly.

Good bio filtration and an active cycle will convert ammonia to nitrites to nitrates. Nothing removes the nitrates, except for them being used by live plants, so you have to do water changes to get them out. If your bio filter is off, your tank not cycled or you have too heavy a bio load, you also will have to manually remove ammonia and nitrites, thus more water changes. Only you can tell if these are problems, and only by regular testing of your water.

Jeff

[nc0gnet0]

Nothing removes the nitrates, except for them being used by live plants, so you have to do water changes to get them out

Actually this statement isn't completely true. Purigen for one will help keep nitrates down as will several other products. And for the real DIY's, you can make a turf algea scrubber.

[jeff@zina.com]

Purigen doesn't remove nitrates, it traps them. Eventually Purigen has to be regenerated, manually removing nitrates from the tank similar to water changes. As for algae/turf scrubbers, algae is plant life. :)

Jeff

[nc0gnet0]

As for algae/turf scrubbers, algae is plant life.

LOL, ok, but the algea scrubbers I am refering to exist outside the tank much like a canister filter, there is a huge thread on it over at monsterfishkeepers for those that are interested.