Return pump making too much noise?

Konigstiger · Jul 11, 2023

I have just finished setting up my tank and sump, but I have one major issue: the return pump is making a lot of noise. From what I can see, I think it is because the pump is too powerful and is sending water back up to the display tank way too quickly and therefore is sucking in air and making the noise. But if so, that would be strange because the pump was sold together with the tank and sump (it is a Reef Octopus OctoLux system) and therefore shouldn't be too powerful for it. I have also turned the knob on the pump all the way to the left which I assume is its lowest setting, but even then, it is still sending up water very quickly and sucking in air.

Is there any way I can fix this? I think the pump might break if it is sucking in air instead of water, and the noise is pretty loud even with the cabinet closed on the sump. I have never set up a tank or a sump before, so please let me know if I even have the correct diagnosis here or if there is another problem that is causing the pump noise or if there is something obvious I may have missed.

I'm not home at the moment, but for reference, I have attached a picture of a similar sump and return pump to this post so that you can see what equipment I am working with in case that helps.

shakacuz · Jul 11, 2023

in your configuration, where is the ball/gate valve located? drain or return?

csturgis1989 · Jul 11, 2023

If it is sucking air then either your overflow is not returning water to the sump fast enough in which case you need to tune the return valve or there is not enough water in your system. Auto top off sensors should be placed in the return section of your sump once you have everything set up properly.

Konigstiger · Jul 11, 2023

So I think I figured out the problem (of course moments after posting this thread) - I think I just put the return pump in the wrong section of the sump. I believe I have put it in the freshwater reservoir section instead of the return pump section, which is why it isn't getting enough water. I haven't had the chance to test if this is the issue yet, but I'm pretty sure that should be it. I'm not sure if users can delete threads here, but yeah sorry to everyone who replied and thanks for trying to help at least. Sadly the tank and sump came with virtually no instructions so I am learning as I go.

But as you can see, I'm not very familiar with how sumps work or plumbing in general. As long as this thread is still up, does anyone know how the freshwater reservoir is supposed to work? I assume I fill it with non-saltwater and then the float valve in the return pump section of the sump tells it when to top off with freshwater or something? There is also a small hole connecting the return pump section and the freshwater reservoir section at the bottom of the sump, so wouldn't water auto flow anyway?

1112-425XL · Jul 11, 2023

System may need more water. Sounds like return pump chamber is low on water. Then fine tuning, and it usually takes a few minutes to react to small adjustments.

1112-425XL · Jul 11, 2023

Mine has a tube connecting the ato to the float valve

Konigstiger · Jul 11, 2023

1112-425XL said:
Mine has a tube connecting the ato to the float valve

I'm sure this is a dumb question, but is the ATO located at the top of the display tank? What is the relationship between the ATO, freshwater reservoir in the sump, and the float valve?

My float valve also has a tube that goes up into the display tank. I assume that the tube is connecting to the ATO you mentioned?

1112-425XL · Jul 11, 2023

ATO is automatic top off, or fresh water reservoir. It supplies the sump with water as it evaporates.

Konigstiger · Jul 12, 2023

Konigstiger said:
So I think I figured out the problem (of course moments after posting this thread) - I think I just put the return pump in the wrong section of the sump. I believe I have put it in the freshwater reservoir section instead of the return pump section, which is why it isn't getting enough water. I haven't had the chance to test if this is the issue yet, but I'm pretty sure that should be it. I'm not sure if users can delete threads here, but yeah sorry to everyone who replied and thanks for trying to help at least. Sadly the tank and sump came with virtually no instructions so I am learning as I go.

All right, maybe this thread doesn't need to be closed... I tried this solution of moving the return pump to a different chamber with more water, and it doesn't seem like it worked. When I did this, the flow in the display tank suddenly became quite tumultuous and started making a lot of noise like a waterfall and made the display tank cloudy, as if the return flow was too strong or something. Also, it seems like I did have the return pump in the right chamber in the first place and that I was mistaken to move it.

Here is the diagram of my actual sump for reference:

The issue I've been having is that the water comes down from the display tank into the tubes on the right, flows into the main sump compartment where the large protein skimmer is, then goes into the small compartment with the float switch and enters into the return pump chamber through a small hole in the bottom, which occurs way too slowly so the return pump is just sucking in air most of the time.

Anyone know what the issue is here? Would adding more water fix this as a couple people have suggested above?