Weir flow....

[Awsam]

Having read numerous threads on here advising that a 25mm bulkhead

will allow 2500-3000 litres of water into the sump, is there any reason why

my 25mm hole is pumping over 4500 litres?

I'm using all 25mm tubing from the weir into the sump and have a 4500 litre pump.

I have had to close the valve slighty as too much water is coming into the sump??

[Josh]

Depending on the head height and brand of pumps the flow coming into the sump way well be as low as 2500lph.

If you are closing a valve to restrict water flow then i would have to say your tank will be overflowing one day. I would say the valve is restricting airflow through the pipe and not water flow

[CThompson]

Having read numerous threads on here advising that a 25mm bulkhead

will allow 2500-3000 litres of water into the sump, is there any reason why

my 25mm hole is pumping over 4500 litres?

I'm using all 25mm tubing from the weir into the sump and have a 4500 litre pump.

I have had to close the valve slighty as too much water is coming into the sump??

What you are saying doesn't make sense, you need to provide much more information.

For example, you say;

Allow 2500-3000 litres of water into the sump

Water into sump is usually under gravity feed

Is there any reason why my 25mm hole is pumping over 4500 litres

This is a bit of an oxymoron from the previous quote as it is describing something pumping water under power, where as the first is a gravity feed, and they are in the same sentance.

My guess, from what you have written, it sounds as though you don't have enough water in the system. To have to reduce water flow to the sump, may mean there is not enough water.

[fongyfong]

My 4500l pump is working fine and is flowing at full speed. The issue I'm having is trying to undrstand why a 25mm bulkhead would allow more than 4500 litres of water being gravity fed into the sump from the weir. I have only reduced the flow to the valve leading into sump from the weir.

so from the weir to the sump the water fluctates? up and down and not a consistent flow when at full speed?

[Josh]

I think you probably dont fully understand what we are saying. What brand of pump is it you are using? Do you understand that pumps will loose pressure the higher they pump?

You can not reduce the flow of water to the sump without the tank over flowing. Its a simple concept, only the water you pump into the tank can flow back to the sump. If you restrict the flow of water to the sump the tank will over flow.

[CThompson]

My 4500l pump is working fine and is flowing at full speed. The issue I'm having is trying to undrstand why a 25mm bulkhead would allow more than 4500 litres of water being gravity fed into the sump from the weir. I have only reduced the flow to the valve leading into sump from the weir.

so from the weir to the sump the water fluctates? up and down and not a consistent flow when at full speed?

relax guys it working fine

I was just wondering why a 25mm bulkhead turns over more than 4500litres

per hour in my tank.

I read here that a 25mm turns over only about 2500-3000litres.

water is tricky stuff

I personally have not read the info you mention, but I understand that you have no problem that you want help with, it was just a "query" type posting.

The only thing I would add is that better this way around than the other