What size holes to Drill?

[porkosta]

Hi All,

After being without a tank for a few years I am looking to get back into it and am in planning stage.

I am looking at doing a 5x2x2 tank with a 3ft sump tank with the BeanAnimal overflow method. I am looking at having the overflow box inside the tank and not on the back like some people have due to where the tank will be going.

My question is, What size holes does anyone with Beananimal overflow have drilled? I am looking at having 3 x 40mm holes for overflow on one side of the back of the tank and another 40mm hole on the other side for the return. What are you thought on this size holes?

Also how far down from the top do you drill the holes?

Thanks,

Andy

[benno84]

all depends on how much your pumping back up. 4x40mm is a fair bit of drainage.

[porkosta]

Will be aiming at getting the highest flow possible.

The flow will be adjusted by ball valves as needed but I am thinking the bigger the pipes then there should be less of a chance of blockage.

What want to hear how everyone else has their setups done.

[ozbloke74]

My 4*2*2 has one 40mm hole to feed sump and 1 25mm hole return to tank, fed with a 5500lph pump which gives me roughly 10 times turnover. Its quite, doesn't surge and doesn't spill over chambers in sump. Two wavemakers aimed at surface blast any floaters in to sump and with the addition of filter floss and carbo pad in sump, keeps water crystal clear. Do I think 3 holes to drain is overkill In a tank that's 5 * 2, yep

[rosco]

A 40mm hole will fit a 32mm bulkhead do in reality it is a 32mm outlet. The important think to avoid is backflow. So what I do is drainthe tank one size higher than inlet. So if the water is coming in via 25mm it goes out at 32mm this will break any vacuum. That is my rule of thumb

Cheers

Rosco

[porkosta]

My 4*2*2 has one 40mm hole to feed sump and 1 25mm hole return to tank, fed with a 5500lph pump which gives me roughly 10 times turnover. Its quite, doesn't surge and doesn't spill over chambers in sump. Two wavemakers aimed at surface blast any floaters in to sump and with the addition of filter floss and carbo pad in sump, keeps water crystal clear. Do I think 3 holes to drain is overkill In a tank that's 5 * 2, yep

Thanks for you input. What you have is what I running on my old tanks 8 years ago.

The only thing is that I have allowed for extra flow and a fail safe should the pipes block to prevent a flood.

[ozbloke74]

I had a screen on overflow box which stopped the little bristlenoses , unfortunately 2 big Bristle noses which I had bought that very day muscled under it and in to sump feed, effectively blocking pipe. lots of water all over floor, an angry wife , 2 deceased bristlenoses and a heater in about million bits when it went bang in the drained sump. Rectified this by making a screen out of Perspex with holes drilled in it , other bristle noses have given up trying to get past my barrier now, expensive mistake but a good learning curve , haven't had a problem since.