UNS R90 Sump

[MaPePo]

I’ll caveat this is my first aquarium with a sump and this is likely a stupid and obvious question.

I just setup a UNS R90 and love it but for the life of me I can’t figure out why they would put a solid “window” in the refugium chamber of the sump that leads to the return pump chamber.

I want to leave plenty of space for water if my return pump/power went out but also plenty of water feeding to my return pump chamber so the pump doesn’t run dry. I’m fine tuning the overflow, skimmer chamber, etc and find I need to keep a close eye on the return pump water level.

Why wouldn’t there be two slotted windows to safeguard the water level of the return pump? It’s removable but before I do I want to try to understand the original reason.

 

[Red_Beard]

I may be wrong, and please feel free to correct me if i am, but I would expect that the solid window reduces the amount of water it takes to change the water level in the return chamber, which is usually where the ato sensor goes. That would keep the salinity swings to a minimum. If you use a slotted one down lower, the whole volume of the sump would react as one vs just the volume of the return chamber.

 

[Cdub925]

I may be wrong, and please feel free to correct me if i am, but I would expect that the solid window reduces the amount of water it takes to change the water level in the return chamber, which is usually where the ato sensor goes. That would keep the salinity swings to a minimum. If you use a slotted one down lower, the whole volume of the sump would react as one vs just the volume of the return chamber.

Also usually before return it has a bubble trap sponge to of course stop bubble from getting to display but also any from fuge if you have one or just detritus

 

[MaPePo]

I may be wrong, and please feel free to correct me if i am, but I would expect that the solid window reduces the amount of water it takes to change the water level in the return chamber, which is usually where the ato sensor goes. That would keep the salinity swings to a minimum. If you use a slotted one down lower, the whole volume of the sump would react as one vs just the volume of the return chamber.

That seems right and I don’t have my ATO setup yet so that will fix that.

 

[MaPePo]

I may be wrong, and please feel free to correct me if i am, but I would expect that the solid window reduces the amount of water it takes to change the water level in the return chamber, which is usually where the ato sensor goes. That would keep the salinity swings to a minimum. If you use a slotted one down lower, the whole volume of the sump would react as one vs just the volume of the return chamber.

Also usually before return it has a bubble trap sponge to of course stop bubble from getting to display but also any from fuge if you have one or just detritus

I’m guessing the thought is the slotted top screen acts as a bubble trap? I haven’t seen any R90 tank build threads with something added there to act like a bubble trap but I’ll keep looking.

 

[Red_Beard]

You should be ok without a dedicated bubble trap. Some of the older skimmers pumped bubbles into the skimmer chamber and the bubble trap really helped a bunch there. That or if you have a ton of flow through your sump it can make bubbles that could find their way to the pump. But, you dont want a ton of flow through your sump and are probably going to be using a more modern skimmer, so you are more than likely goi g to be just fine without a bubble trap

 

[UNS_Brandon]

You can swap the position of the slotted and solid windows if you want. Having the lower solid will help contain microbubbles and better keep macroalgaes from getting pulled into the pump chamber.

If you are using your own ATO, make sure the sensor goes in the pump chamber and should keep your pump from running dry. You'll notice it in your display immediatley if your pump is pulling in air though.

 

[MaPePo]

You can swap the position of the slotted and solid windows if you want. Having the lower solid will help contain microbubbles and better keep macroalgaes from getting pulled into the pump chamber.

If you are using your own ATO, make sure the sensor goes in the pump chamber and should keep your pump from running dry. You'll notice it in your display immediatley if your pump is pulling in air though.

That makes sense, and water level has been less of an issue lately so I decided to leave it. Everything has been working very well and I love the tank, except I’m struggling with the built in gravity ATO. It seems like the float valve gets hung up and dumps water, too much water, to the point my salinity will drop a little. It’s happened repeatedly and I’m considering switching to the Hydros optical sensor ATO. Does UNS have any instructions for setting up the float valve in the return chamber?

 

[UNS_Brandon]

Its tough to see in your photo, but it looks like your float valve may be at an angle. If it's still like this, straightenout the bracket.

You need the float valve to be properly orientated or else increased friction at the pivot point can cause it to get "hung up" like you described. The float needs to be able to very freely move up and down.

If you need additional help, do not hesitate to message us at the dedicated email address, [email protected]

Side notes:
1. While you're back there, you will want to shorten your dosing lines so that they're above the water level.
2. That hole at the top is to allow you to pass through wires. I think I see a temperature probe in your refugium chamber. You can run that wire through the hole at the top and and out the pump chamber if you want to tidy up the lines.

 

[UNS_Brandon]

Hi! Following up on this.

 

[vinsk]

I’m really curious how your ATO worked out, if it did. I have the R75 and everything is immaculate except for this ATO float valve mechanism. Nothing but headaches.
I took mine out and tested it at the sink and it release water and closed appropriately. After three and half hours of arthritis inducing hand manipulations and Himalayan yoga positions, I was able to reinstall it only too see it dump water and not shut off when all the up.

 

[UNS_Brandon]

@vinsk while water was still emitting from the valve (after the point in which you wanted it to stop), does manually lifting the float, stop the flow? If so, you need to change the pitch of the float downward so that more pressure is applied as the water rises.

Also ensure that the mounting bracket is vertical and not slanted as in my drawing above AND nothing is preventing free movement of the float.

 

[vinsk]

@vinsk while water was still emitting from the valve (after the point in which you wanted it to stop), does manually lifting the float, stop the flow? If so, you need to change the pitch of the float downward so that more pressure is applied as the water rises.

Also ensure that the mounting bracket is vertical and not slanted as in my drawing above AND nothing is preventing free movement of the float.

Yes! I got an email from UNS and they even included a video showing the adjustment. I’m going to do that Saturday morning. I really hope I can access the screw and avoid removing the whole mechanism.
They also said they think my emergency pipe appears a little too high and asked if I can push it down 1-2cm. I’m gonna shut my pump off and also make sure I have the proper water levels.
Last time I shut my pump off…panic set in as the sump began to overflow. Luckily I was able to stop it before it got bad.

 

[UNS_Brandon]

If your pump is overflowing when your return shuts off, your baseline water volume in the sump is too high.

1. Do you have the adjustable baffle between your protein skimmer chamber and refugium chamber set to very high?
2. In the pump chamber, you really only need enough water to keep your pump from pulling in surface air.

 

[vinsk]

Ok. I siphoned out some water and now have it when I shut the pump off the sump can handle the volume to about 1.5” from the rim. Please excuse my ignorance in the sump workings..lol.
I’m not running my protein skimmer as I’m just in the cycling phase, but yes the baffle is high between the skimmer and refugium.
Will this help with the return compartment level?
The return compartment is too high as you said, I only need enough to not draw air…but mine is well above the pump which makes the float valve improper.
I’m about to adjust the float arm to a more downward angle as you recommended but need to get the pump compartment at the proper level as well…that’s what I’m struggling with.

 

[vinsk]

Going well today. Was able to tap down the emergency pipe, adjusted water to be much better in the return compartment and set the baffle between the skimmer and refugium to the bottom which makes my water level there about 8”. May have to adjust for skimmer in the future.
Going to test the ATO system and see how it’s doing.