How many drilled holes can a tank handle?


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Just how many holes can you put in a tank?

I'm currently designing a new system (6 X 2 X 2) and i'm planning on running two closed loops. The total number of drilled holes i'd need would be as follows:

2 closed loops each requiring 2 inlets and 4 outlets - so 12 in total
overflow weir - 2 holes
sump return pumps - 2 holes

That's 16 in total. 6 on the bottom and 10 on the back of the tank.

Is this bordering on the ridiculous? Should I start thinking of new ideas??

If your bottom is tempered glass, you wont be able to drill it without the chance of it shattering. I have a CLM and have 3 inlet, 3 outlet and 1 return to sump, all 45mm. I don't think it would go with that many. What I might do, in your situation is drill the back for 1 overflow, the inlets and maybe 2 outlets. I would then use a halo, google Calfo CLM for the rest of the returns.

Now, you need to be careful on the CLM design, if you have more returning to the tank than you are taking in, you stand a chance of cavitation in your CLM pumps.

What size are you planning your inlets? Your outlets? your intake to your sump/fuge?

Here is a link to my build, including the drilling;
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Thanks for the response - i've also had a good read of your other informative thread.

I'm planning on using sequence 10k pumps each with 2 x 1 inch inlets. The returns would be 1 inch each. I'm presuming that would reduce the flow through them enough for it to work. maybe i could limited the closed loop on the base to 2 larger inlets then have pipewrok under the DSB where I could reduce and give myself 4 outlets.

For the CL on the back i could again limit it to 2 inlets using the nozzles you have on yours to direct the flow in two different direction from each.

I could also have the sump return pumps coming over the top of the tank.

This would give me 4 holes in the base ( 2 CL outlet and 2 overflow weir) and 6 in the back (4 CL inlet and 2 outlet)

Do you think this would work if I tried to keep the holes apart from each other?