Help Our Sump Doesn't Work!

[sarahw20000]

Hi everybody

We have a problem with the large glass object in our lounge that has so far cost us about £1500!!!

It's 83" long, 20" wide and 28" high with an approx capacity of 750 litres.

It's sump is 36" long,12" wide by 17" high and has 5 sections, in order from intake to return there is foam, k1 bio media, filter wool, heaters and pump.

It has a weir in the left corner with a durso standpipe and the return pipe comes up in the right corner with a non return valve on it. We also have a ball valve on the pipework going into the sump. Pipework is 40mm and pump is oceanrunner 6500.

Now we filled the tank up a few weeks ago with no decor or gravel and nothing in the sump and managed to get the balance between the pump and the water flow into the sump just right so you could leave the whole lot running and nothing ran dry or overflowed.
-I should point out that at this point there was no standpipe, the water just ran into the weir and down the hole at the bottom and there was also no valve on the return pipe.

We put the decor, gravel and all filter media in this weekend and tried getting the balance right and it just wouldn't work.-
-The pump drains it's section of the sump too quickly, the weir drains too quickly so the water level goes below the standpipe constantly, and the water in the first sections of sump rise too quickly because it's backed up behind the media.

We've tried removing all of the filter media but the pump still runs dry and we've tried putting more water in the whole thing so the weir doesn't drain but nothing seems to work.

If anyone has any ideas of what could be wrong please help, also if anyone knows of a person or company that knows all about sumps that i could pay to come round and make it work i would be hugely gratefull.

Thanks

 

[andywg]

Sounds to me like the pump is too powerful and is putting too much water into pipes and the display tank. It would appear that the final chamber is too small and does not hold enough water to cope with the pump filling the pipes and raising the water level of the display tank.

The quickest solution I can think of is to use a less powerful pump.

 

[mr.dark-saint]

Sounds to me like the pump is too powerful and is putting too much water into pipes and the display tank. It would appear that the final chamber is too small and does not hold enough water to cope with the pump filling the pipes and raising the water level of the display tank.

The quickest solution I can think of is to use a less powerful pump.

That or you don't have enough water in the sump. Or the media you're using is too fine and the water takes a little longer to go through the "hoops". Or simply all three.

 

[sarahw20000]

Ahh so basically it's all wrong!
The first time we balanced it all out so the pump wasn't too powerful then, if anything there's less water going back into the tank because the non return valve restricts the flow a bit.

We've tried it with more water in the sump, and the main tank and we've tried it with no media at all so i don't think it's any of them.

by my reckoning it must have something to do with the non return valve and the standpipe because they're the main differences between when it worked and now.

How do other normal people do this?

 

[andywg]

I don't use non return valves or any restrictions on the standpipe.

You want a fairly large amount of water in the final chamber to prevent the water level dropping too far. I have learned this the hard way.

I never have to balance the tank. I always make sure the drain can more than cope with the return and then there is no problem. For a tank that size I would have considered two 40mm standpipes. Probably more than necessary, but prevents too much back up.

However, I think the problem is one of two things:

1) The pump is too powerful for the final chamber size and is just putting too much up into the tank

2) Somehow the standpipe is running too close to max capacity and is restricting the flow back a little causing too much water to be held in the display tank.

If it was because of media you would have seen the other chambers overfilling and I assume that hasn't happened.

 

[dylema]

I just had a thought. What if you shortened the standpipe so there is a bigger difference in water hight from tank water level to standpipe and therfore you would increase the pressure and more water should flow through the stand pipe. Andywg do I have the right idea here?

Dylan

 

[sarahw20000]

We've tried it with the standpipe lower and it still drained the weir whilst not filling the sump enough.

When there was filter media in there, the sections with it in were overfilling with the last pump section still draining.

I made the final chamber double the size of the rest of the chambers.

Would it be possible to put a ball valve on the pipework under the tank, after the pump to adjust the flow of the return so the final chamber doesn't drain as quickly and then we could turn the flow from the weir down so that doesn't drain too quick aswell?

 

[andywg]

We've tried it with the standpipe lower and it still drained the weir whilst not filling the sump enough.

When there was filter media in there, the sections with it in were overfilling with the last pump section still draining.

I made the final chamber double the size of the rest of the chambers.

Would it be possible to put a ball valve on the pipework under the tank, after the pump to adjust the flow of the return so the final chamber doesn't drain as quickly and then we could turn the flow from the weir down so that doesn't drain too quick aswell?

You can put a valve on to restrict the flow, but be careful as it will create more pressure and strain for the return pump. A better way is to have a T section and then a avalve after each branch. Have one go to the tank, the other back to the sump, so that it doesn't strain the pump.

 

[sarahw20000]

[/quote]
You can put a valve on to restrict the flow, but be careful as it will create more pressure and strain for the return pump. A better way is to have a T section and then a avalve after each branch. Have one go to the tank, the other back to the sump, so that it doesn't strain the pump.
[/quote]

Yeah we were worried it might be detrimental to the pump, i don't understand what you mean with the T sections though?
There is a ball valve already going back to the sump but we have to have it fully open at the mo because of the overpowerful pump.

 

[andywg]

Yeah we were worried it might be detrimental to the pump, i don't understand what you mean with the T sections though?
There is a ball valve already going back to the sump but we have to have it fully open at the mo because of the overpowerful pump.

Sounds like you have already done it then.

My ponit was, rather than just having a single straight piece of pipe from the sump to the display tank with a ball valve to restrict flow (which it does by increasing the back pressure on the pump) you have it so that you can take some of the water from the pump and divert it back into the sump.

As I mentioned above, it seems you have already done this.

 

[sarahw20000]

Ahh no we havn't done what you meant, our ball valve is on the pipework coming from the weir to the sump.

I've had another look at it and I'm pretty sure we can put a ball valve after the pump because the attachment the pump comes with is for around 25mm pipework and we bought a hexagon adaptor and put 40mm pipework so it's actually got more freedom than it needs, also because it's pumping up 1.5m high it loses power and apparently they like to work against something if they're working at less than max power.

However i think i'm going to order two ball valves, one to fit the 40mm pipes to go after pump, up to tank and the other smaller one with a T piece and some smaller pipe to go straight from pump back into pump chamber in sump. If you're still following, this way if the main ball valve has to be closed too much to make an effect on the other problems i can open the little one, therefore still keeping the pump chamber full enough and taking the pressure off the main valve and the pump.

Ahh deep breath, i was kind of still trying to work out what i meant whilst typing.

So do you get what i mean and would that be a good idea?

 

[andywg]

That sounds about right, but why have a ball valve on the drain from weir to sump? the speed of drain is governed by either the diameter of the pipe (bad - means the pump is too strong) or the power of the pump and the amount of water it is pumping up.

 

[Fatty]

I think you need to get back to basic principles and work from that..

Pump water up to the tank and let if flow down the overflow to the sump again...

make sure the output of sump pump is near the top of the main tank (stop back siphoning in a power cut)

make sure the drain/overflow in the main tank can take the volume of water (there should always be an amount of air being sucked down the stand pipe).

If the sump pump chamber runs dry this is either because the drain in the main tank cannot take the volume (in which case the stand pipe will be submerged with a head of water above it/ too much water in main tank)

or

there is not enough water in the whole system

or

the media in the sump is causing too much restriction (if this is the case I would allow the excess water to overflow over the top of the media to the sump pump chamber or you could just throttle the pump back using any of the previous methods)


nb: most water pumps have a longer life with some restriction on them, for the most part the restriction of 1 metre head of water is enough.

I would get rid of all valves etc.., and if you need to throttle the sump pump back then put a T piece from the pump in the sump to the sump (if you see what I mean), by putting a gate valve or such on the T piece exiting in the sump it will allow you to controll roughly how much water is pumped up to the main tank.
(this way you will only have the one valve in the sump to potentially get blocked or siezed etc..)

i.e, some is recirculated thru the gate valve into the sump and the rest is up to the main tank.

Hope this helps

 

[mr.dark-saint]

What Fatty said rings true. Try it out without any restrictors. But to me it still sounds like the bulk head can't handle the overflow volume. I wonder the bulkhead to sump hose is smaller diameter. On mine I just slipped a clear vinyl tube over the bulkhead (this way there is less restriction for the return. I also don't have any straining thing over the bulk head. Best thing is to turn off the tank and see how much water collects in the sump. I have mine fill about an inch below the top (if less add more water) so I know it will not go beyond that level. I also mark the water level while it's running so I know the working level this helps me know if I need to add water to that line so I don't dry run the pump. For anti-syphon I just have a 1/8" hole on the PVC inside the tank about the water level (when the pump is running).

If you can add the pic of the octopus you have under the tank and the pipe size we could narrow down the issues more accurately .

 

[andywg]

If the sump pump chamber runs dry this is either because the drain in the main tank cannot take the volume (in which case the stand pipe will be submerged with a head of water above it/ too much water in main tank)

or

there is not enough water in the whole system

or

the media in the sump is causing too much restriction (if this is the case I would allow the excess water to overflow over the top of the media to the sump pump chamber or you could just throttle the pump back using any of the previous methods)

Or the final chamber that the pump sits in is too small Believe me, I've done that mistake myself.