Overflow to sump

[spider]

Hi

I am busy building a 2m tank which will hold 500l. Tank Size: 2mx450x600mm high.
My problem is that I only have a 32mm dia. bit to drill the base for the overflow. The tank will have a overflow box with the hole on the base.
Can someone advise me about the amount of water this oveflow can take down to the sump in an hour or wll I need 2 overflow boxes.

Regards.

[neilh]

On my 1.8X60X60, I have a twin durso going from 50mm to 32mm. I can run the tank comfortably with only 1 overflow line, restricted to about 50% with a ball valve. Return pump is ~ 3000lph

[Fonkie]

Hi

32 mm will be fine - but everything boils down to the size pump you want to use - ussually you want to cycle your tank 3-4 times per hour. So you gonna need a 2000 liter pump.

[Reafer]

the Max flow you can get out of a 32mm pipe is 6300 L/hour. But with a gravity feed and a bit of tank pressure u looking at around 4000L/hour

[spider]

Thanks Guys

I have a 3500l/h pump but will fit a valve on the supply back to the tank.

Thanks again.

[sarf]

Hi yagya..y dont you drill two holes to hav two outlets to the tank

[Sean]

Hey bud I agree with Sarf drill two holes. If you do drill let me know I need holes drilled in my 12mm 2m tank. Sean

[spider]

Morning

Normally I only drill the outlet to the sump and then bring the return with a 90deg. bend over the back of the tank onto a spraybar that will run the full length of the tank.
Sean, I do drill my own holes but only have the 32mm dia. bit. I can drill yours but the risk is yours. I drilled quite a few tanks with success but one never knows. Also I will not drill glass that is very old.

Thanks for your input guys.

[Sean]

Hey bud give me a call so we can organise as I have lost your number once again. Thanks Sean

[neilh]

If you going to drill 2 holes, make very sure that pipe lengths are exactly the same. Balancing 2 different length overflows is incredibly difficult, I speak from experience

[mydummyname]

post pics as you do it boet ;)

[spider]

ok will take some pics tonight

[Donovan]

i have 2 hold drilled in my overflow one is a 50 and the other a 32, the 32 is my return from my sump, the nice thing is you dont see any pipes over the back of my tank.

i have light trays in my tank so the return runs thru the bottom of the light tray then along it and back down into the tank thru another hole in the tray, if i remember ill take a pic tonight and show you what i mean.

why do u need to put a valve on the pipe that goes to the sump, it cant flow out faster than what ur return pump is supplying the biggest problem would be that it cant get out of the tank fast enuf and putting in a valve in my opinion is just a waste of time and money

[spider]

The valve will be connected on the supply from the sump pump to the display.
this way i can regulate the flow from and to the tank and wont end up running the pump dry.
As mentioned by 'Vonkie and Reefer' the 32mm in the overflow should be ok.

[Singularity]

why do u need to put a valve on the pipe that goes to the sump, it cant flow out faster than what ur return pump is supplying the biggest problem would be that it cant get out of the tank fast enuf and putting in a valve in my opinion is just a waste of time and money

valve on the overflow line is there so that you can throttle the flow and get rid of gurgling noises etc.

---------- Post added at 21:09 ---------- Previous post was at 21:09 ----------


The valve will be connected on the supply from the sump pump to the display.
this way i can regulate the flow from and to the tank and wont end up running the pump dry.

Only way of running the pump dry is when you dont top up, and if something goes wrong, like a clogged pipe. No need for the valve on the return line, rather put it on the overflow line.

---------- Post added at 21:09 ---------- Previous post was at 21:09 ----------

here is a pic of my tank, overflow in the center and the return split into 2 on the left and right.

http://i278.photobucket.com/albums/kk85/singularity96/SAM_0145.jpg

[Linga]

The valve will be connected on the supply from the sump pump to the display.
this way i can regulate the flow from and to the tank and wont end up running the pump dry.
As mentioned by 'Vonkie and Reefer' the 32mm in the overflow should be ok.

dont put a valve on your pump you will only be reducing the head and putting undue strain on the pump. i have a 4000 liter/ hour pump on my tank and only use 1 32mm drain and i have a valve on that so the drain is about half closed and still drains no problem. i suggest you drill 2 holes make one higher than the other, should the first one clog the second will be you emergency drain. Put a "durso" on the first so no sound, leave the second as a vertical pipe so that it makes a loud as possible sound so you know when you have a problem and you emergency drain is running. hope this helps.

[mydummyname]

curving the outflow pipe/pipes should make the water flow along the insides of the pipes inside of just dropping straight down, this should eliminate air pockets, which is what causes the gurgling sounds..

[DanH]

Use a durso(stand pipe with a T-piece, elbow and end cap with a tiny hole drilled in the end cap)

If you want to put in a throttling valve then you need T-piece straight after the return pump, the extra pipe goes back into your sump and the valve is on this extra pipe. So fully closed is maximum flow to the DT and slightly open will give less flow to the DT.

You don't want to make a potential blockage point or strain the pump.