Still having a nightmare with sump, please help!

Abi Jones

Member
Joined
4 Jul 2019
Messages
42
Location
Southampton
Every time I start up the pump again after doing maintenance the flow into the sump starts surging, by this I mean that instead of a constant flow into the sump it’s alternating between niagara falls and a trickle. Does anyone have any ideas why it would be doing that? It usually evens out after a day or two but I’m sure this shouldn’t be happening and it’s extremely annoying! I have a durso up top and a reverse durso at the sump, with just coarse sponge in the first chamber.



Sent from my iPhone using Tapatalk
 

ScareCrow

Member
Joined
28 Jan 2019
Messages
61
Location
South west
Hi Abi, could you post a pic of the reverse durso? It's hard to see the top of the upstand on the left, which helps remove air. From the video, it looks to me like it's creating a vacuum in the system.
In your other thread about the noise coming from the sump. It might be worth adding a small adjustable valve to the top of the cap. It might not make much/any difference if the hole is already the optimal size but it would allow you to tune the amount of air entering the system.
 

Abi Jones

Member
Joined
4 Jul 2019
Messages
42
Location
Southampton
Hi Abi, could you post a pic of the reverse durso? It's hard to see the top of the upstand on the left, which helps remove air. From the video, it looks to me like it's creating a vacuum in the system.
In your other thread about the noise coming from the sump. It might be worth adding a small adjustable valve to the top of the cap. It might not make much/any difference if the hole is already the optimal size but it would allow you to tune the amount of air entering the system.


Thanks so much for replying, I feel like I’m never going to get this right! Where exactly would I put the valve? The dursos are both a bit thrown together and prob not ideal- it is noisier without them but it’s by no means quiet with! I think you’re right about the vacuum, I was worried there was pressure building up somewhere and then releasing causing the fluctuating flow.


Sent from my iPhone using Tapatalk
 

ScareCrow

Member
Joined
28 Jan 2019
Messages
61
Location
South west
I'd put the valve in the hole in the overflow cap (see pic). Can you explain what the arrangement is with the reverse durso, in regards to the plack hoses? Is the top capped off and are those connected through the cap?
If you pull the black sponge out from under outflow pipe, so the flow isn't restricted, does it still pulse?
IMG_20201120_184517.jpg
 

Abi Jones

Member
Joined
4 Jul 2019
Messages
42
Location
Southampton
I'd put the valve in the hole in the overflow cap (see pic). Can you explain what the arrangement is with the reverse durso, in regards to the plack hoses? Is the top capped off and are those connected through the cap?
If you pull the black sponge out from under outflow pipe, so the flow isn't restricted, does it still pulse?
View attachment 156639

They are to let air out. I read that was what you were supposed to do, is that wrong? Without the cap with air hoses it gurgles really badly. I haven’t tried without the sponge at all but it’s quite open cell and doesn’t go all the way to the bottom of the chamber. I’ll take it out tomorrow and see if that helps. The top durso doesn’t look like that anymore, I’ll take a pic.


Sent from my iPhone using Tapatalk
 

Ed Wiser

Member
Joined
22 Apr 2018
Messages
355
Location
Louisville,Kentucky
Who suggested a dorso at the outlet into the sump. I have been using sumos for 35 years in Saltwater and have visited thousands on people’s homes across the USA. This is going to cause flow balance issues. No wonder you are having an issue. The dorso method was developed by a friend of my years ago. It was developed to remove the suction of air down the overflow from the tank into the sump. When you block the outflow of water into the sump water will back up into Down tube pipe. This cause a flow imbalance.
 

Abi Jones

Member
Joined
4 Jul 2019
Messages
42
Location
Southampton
Who suggested a dorso at the outlet into the sump. I have been using sumos for 35 years in Saltwater and have visited thousands on people’s homes across the USA. This is going to cause flow balance issues. No wonder you are having an issue. The dorso method was developed by a friend of my years ago. It was developed to remove the suction of air down the overflow from the tank into the sump. When you block the outflow of water into the sump water will back up into Down tube pipe. This cause a flow imbalance.

I can’t remember where I read it, but was having noise issues so gave it a go and it did help with the noise a little. I’ve just tried taking the reverse durso at the sump off and having water flow unrestricted into the sump, it still does the surging thing So I presume it must be an issue with the top durso? If I take photos of the whole set up tomorrow and post here would you mind advising?


Sent from my iPhone using Tapatalk
 

ScareCrow

Member
Joined
28 Jan 2019
Messages
61
Location
South west
Yeah it would be good to see how the whole system is working. I'd leave the bottom durso off and try to get the top working efficiently before adding complications lower down. The bottom durso shouldn't be restricting the flow though, as it's still a straight path for the water. All the bottom durso is trying to do is remove some of the air before it gets into the sump, reducing turbulence and noise. The black sponge might have been restricting the flow if the down pipe was pressed up against it but if you've removed the bottom durso and still have the pulsing issue it's not the cause.
 

Abi Jones

Member
Joined
4 Jul 2019
Messages
42
Location
Southampton
Yeah it would be good to see how the whole system is working. I'd leave the bottom durso off and try to get the top working efficiently before adding complications lower down. The bottom durso shouldn't be restricting the flow though, as it's still a straight path for the water. All the bottom durso is trying to do is remove some of the air before it gets into the sump, reducing turbulence and noise. The black sponge might have been restricting the flow if the down pipe was pressed up against it but if you've removed the bottom durso and still have the pulsing issue it's not the cause.

Thanks so much for helping, I’ll be back tomorrow. At this point I’ve just had enough of the whole sump thing, it shouldn’t be this difficult to get right!


Sent from my iPhone using Tapatalk
 

Abi Jones

Member
Joined
4 Jul 2019
Messages
42
Location
Southampton
Yeah it would be good to see how the whole system is working. I'd leave the bottom durso off and try to get the top working efficiently before adding complications lower down. The bottom durso shouldn't be restricting the flow though, as it's still a straight path for the water. All the bottom durso is trying to do is remove some of the air before it gets into the sump, reducing turbulence and noise. The black sponge might have been restricting the flow if the down pipe was pressed up against it but if you've removed the bottom durso and still have the pulsing issue it's not the cause.

This is the top durso, it did have 2 air lines but added a third and its now stopped surging, is still pretty bubbly where it enters the sump tho.





Sent from my iPhone using Tapatalk
 

ScareCrow

Member
Joined
28 Jan 2019
Messages
61
Location
South west
It certainly looks better than what was there before. It's hard to see from the picture but are the airlines drilled through a cap? The video that Ed posted shows exactly what I was talking about in regards to adding a valve to tune the air flow into the standpipe. That should be all that's needed to get the top of the durso working properly.
 

Abi Jones

Member
Joined
4 Jul 2019
Messages
42
Location
Southampton
It certainly looks better than what was there before. It's hard to see from the picture but are the airlines drilled through a cap? The video that Ed posted shows exactly what I was talking about in regards to adding a valve to tune the air flow into the standpipe. That should be all that's needed to get the top of the durso working properly.

Yes they are. I will try and find a valve for the top then, do you think I should ditch the reverse durso at the sump?


Sent from my iPhone using Tapatalk
 

ScareCrow

Member
Joined
28 Jan 2019
Messages
61
Location
South west
It's a bit of an odd situation. It shouldn't take three lines to vent the stand pipe. I'd stick a valve on each and slowly open one at a time to try and tune the airflow/water level, as the guy in Ed's video demonstrates. When the upper durso is working as good as you can get it, then I'd move to the lower one, if you still feel you need to reduce the noise. I think your reverse durso design was fine, it might be worth adding a bit more length so the bottom of the pipe is below the waterline. There are a few designs discussed here:
 

Abi Jones

Member
Joined
4 Jul 2019
Messages
42
Location
Southampton
It's a bit of an odd situation. It shouldn't take three lines to vent the stand pipe.

Yes that’s why I’m getting so frustrated! I’ll get another cap for the durso and try one larger airline with a valve. Is the point of the airline to vent air out of the system to avoid bubbling? So the more air I can release at the top the less turbulence in the sump is that right? And then the reverse durso gets rid of any air that’s still present.


Sent from my iPhone using Tapatalk
 

ScareCrow

Member
Joined
28 Jan 2019
Messages
61
Location
South west
So the vent at the top, is to restrict the amount of air entering the system. You need to have some for water to be able to enter the stand pipe but excess air results in more noise. You want to reach a compromise between noise and flow. Be mindful that you can't totally cut off the air entering the stand pipe and you'll need to make sure that the valve doesn't get blocked. Otherwise you could have the tank overflow or your return pump run dry. (depending on your pump/sump arrangement, I don't know the layout of your sump, pump position if you have a secondary overflow or volume, so this might not be a concern).
As you say the reverse durso is trying to separate the air, that you had to let in at the top, from the water before it gets into the sump and in doing so reducing bubbling, turbulence and noise.
 
Joined
30 Aug 2020
Messages
122
Location
Bristol
This is the top durso, it did have 2 air lines but added a third and its now stopped surging, is still pretty bubbly where it enters the sump tho.





Sent from my iPhone using Tapatalk
Is yours a single down pipe? Not seen so much water held there

Mines a nuts hight above the glass base and an emergency pipe half way up with its own hole in base
 

Abi Jones

Member
Joined
4 Jul 2019
Messages
42
Location
Southampton
Is yours a single down pipe? Not seen so much water held there

Mines a nuts hight above the glass base and an emergency pipe half way up with its own hole in base

Yes it’s a single pipe down. I couldn’t make it any shorter as didn’t start messing about with it until it was filled so can’t cut the down pipe


Sent from my iPhone using Tapatalk
 
Joined
30 Aug 2020
Messages
122
Location
Bristol
oh right, I have three pipes, two for water going down
one with a ball valve for balancing and a second for emergency use if first blocks, just a straight run
third is the pipe returning water back up again

sometimes if some airs trapped I turn the ball valve to closed, let a head build up and then open back to the mark on the pipe and the extra water rushing down pushes out all the trapped air and silences the setup,
 
Top