Help to set up a small secondary tank

Hi all

I need some expert help.
I have a 9x4x2 tank that i set up myself (with much trial and error!)
I breed stingrays and want to set up a small second tank to house pups. This will run off the main tank and be fed by water pumped by a pump sitting in the sump on the main tank.
The small tank will only be 23" long by 14" wide and 12" tall due to space restrictions. This equates to 63 liters of water.
I have a spare 3000 LPH pump that i want to use.

My question is this.
If i pump 3000 LPH into a tank that can only hold 63 liters, what size bulkheads would i need to fit for waste water to leave the small tank? Obviously some power will be lost due to head on the pump but not sure how much, it will only have to pump about 3.5 feet up to the small tank.
Or is this just too much flow rate coming into the small tank?
I was thinking of putting 3 bulkheads with 22mm flex tubing on the tank to take waste water away and one return bulkhead.

Is this okay in your opinion?
I don't want to do this and then find i am pumping more water into the small tank than can be drained away. This is a mistake i made when setting up the big tank and don't want to repeat this! I had 2 pumps running and the tank filled up quicker than the drain lines could handle taking it away. so i ended up only running one pump.

Hi Joao

Yes i was thinking of using a 'T' to control the flow. I think i may have to rethink the size pipe and bulkheads for drainage as well though, thanks for the input.

Joao M said:

Jim,

I had a 540 lts tank connected to the main sump fed by a 3.000 lts return pump. I used a 40mm drain (outflow) and it was big enough.
However, with a 63lts tank, 3000lts/h is excessive.

I say this because I also had a 112lts tank connected to that sump and it had a 20mm drain. The 3rd tank was fed by a 2100 lts/h return pump and it was excessive. I sorted the problem using a "T" and diverting some of the water from that pump back to the sump.

So, my advise would be to do 2 things:
a) make the drain as big as you can;
b) use a "T" with a valve in the output of the 3000lts return pump to allow you to adjust the flow so that only part of the water woudl go the the secondary tank, the rest going back to the sump.

Hope this helps

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