Preventing Sump overflowing and flood
 

Say if the water intake inside the tank has an overflow and underflow intake to bring the water in tank to the sump tank.

If the pump in sump tank stopped, the overflow intake will take in water from the tank until the lower mark entry on it. As long as the sump tank can hold the extra water, I think there won't be flooding.

What about the underflow intake?? :confused: Will it continue to take in water from the tank until the tank empty? Which means confirm whole room flooded liao! :eek:

Any bros/sis can advise on this?

Nope it wouldnt. The over and underflow both leads to a pipe in the main tank which controls the water level in it. Unless this pipe doesnt function properly, your floor shouldnt get flooded.

you can raise the outlet of the return pipe above water level, drill holes near to the outlet of the return en. or install an anti backflow valve at the pump outlet.

i hope i read your question right.

You are referring to the water returning into the tank. If pump off then water can siphon through the pipe back to sump tank. That's not what I meant. But, thanks for the tip!! :D

Oh, so you mean there's a pipe behind the over/under flow conpartment in the main tank that regulates the water flowing out of main tank and into main tank? So, in this case if the water stop overflowing into the compartment, the water from the under flow will not be strong enough to reach the opening of this pipe to flow into sump tank?

Hahaha yes if both of our understandings are mutual then yes thats exactly what I mean.

As long as your overflow stop at the lower entry mark, your underflow will also stop. Unless is your sump last compartment the water level is quite high already, by then your tank water go into your sump then will overflow


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OK! I didn't know that when the overflow stops, the underflow also stops. Now I know. Thank you! Now I no need worry so much! :D

But why underflow also stop? I don't quite understand:confused:

When theres no additional water added to your tank from your pump, the water level is still at the lower mark. Thats why overflow and underflow dont work when your pump is off. So when you switch on your pump, water is constantly adding in to your tank, thats why excess water above the lower mark will flow out to your ious chamber then to your sump. Just that it has 2 ways to flow out, one is top the other one is bottom. Hope you understand what i mean. Or maybe other bros can explain in a better way. Sorry :)) cheers

Bro, I think i know what you mean. The top tank underflow should work this way.

Like my 5ft tank. The overflow compartment has a opening at the bottom and this opening gap does not goes to the overflow compartment. It has another layer of glass that will draw the water up to the top and overflow down into the overflow space.

You might see in the overflow space have a pipe hole and it is very low. You worry is, is this the guide if pump stop will the top tank water level drops till this pipe opening right ? No... it will not as the over or so call under flow, flow down from the top of the overflow compartment.

Therefore the overflow will stop, once the pump stop working.

Design of overflow system to bottom sump should work this way.

That is to say the divider has two glass panels for overflow and underflow system.

Please note that some have only one glass panel as a divider for the overflow compartment and usually the bottom part do not have any opening for underflow.

I do not have grave and underflow helps to suck unwanted debris at the bottom of the tank. By adjusting a slower flow on the top will force the bottom underflow to work harder.

This type usually have multiple holes at the top for overflow. For me i cover some of the holes and the gravity will draw most of the water from the underflow.

If you have grave or planted soil with this system. The underflow will not work anymore.

:)