Overflow/Return Pump Equilibrium Issues

[RobberyinCSharp1824]

I am complete novice when it comes to sumps and plumbing. I have a 120g tank that's got a Trigger Emerald 34 Sump installed underneath it and a Reef Octopus Varios6 return pump. Since the tank is tempered glass, I have no choice but to go with the overflow method as a means of moving water to my sump. I planned to plumb the system in such a way that given head pressure, the Varios6 would be the best return pump option. This was also recommended by some members on R2R. The CS90 was designed to meet my tank volume (rated up to 125g). I hired my local LFS shops to do all the plumbing work since I've been going to his store for years as a happy customer. Plumbing is NOT in my wheelhouse and I don't feel like flooding my entryway or nuking my tank. I didn't realize my guy would be doing a soft plumb (and insisted that it was better to reduce vibration and noise).

Now, I have a major differential between the return pump rate and the overflow box. This has been going on for two months and none of our fine-tuning methods are sustaining.
I've got the return pump on Eco Mode and it still outpaces the overflow. It's causing my ATO to trigger 10-20 times a day and my salinity is dropping as a result (the tank is fallow; waiting for quarantined fish to be ready to add).

Any thoughts on how to fix this? Here were a few options I am considering:
1. Power off the return pump, let the sump fill to it's "flood" zone, and then top off the DT with water so more water is flowing into the sump. I have more than enough volume in the Emerald 34.
2. Bite the bullet, eat the cost of my CS90 and replace it with a CS100 (rated for tanks up to 175g) or CS102 (rated for tanks up to 250). I suspect I will have to do a hard plumb with a gate or ball valve to regulate flow.
3. Add a second overflow box, probably either a CS50 (rated for tanks up to 60g) or another CS90, install a valve to control flow, and install it on the second input on my sump. Fine tune accordingly.

Help!

 

[ca1ore]

What do you mean by your pump ‘outpacing’ the overflow? If your pump is pushing more water IN than the overflow can drain water OUT then water is going to spill out of your display. Those HOB overflows are notorious for over claiming capacity.

 

[Snoopy 67]

Where are you located?

 

[RobberyinCSharp1824]

What do you mean by your pump ‘outpacing’ the overflow? If your pump is pushing more water IN than the overflow can drain water OUT then water is going to spill out of your display. Those HOB overflows are notorious for over claiming capacity.

I'm saying that the third chamber of the sump, where my return pump is located, is consistently running out of water / the water level is dropping rapidly through the day. If I turned off my ATO and ran my return pump at the lowest level right now, that chamber would probably be empty by tomorrow morning or afternoon. The water levels in the other two chambers seem fine - I moved my ATO sensor to the second chamber at one point, just to see if this was actually just evaporation. The ATO probably turned on....once over the course of two days, so it's not that.

What would you recommend?

 

[Poof No Eyebrows]

Have you tried adding more water to the main display, a little at a time and then waiting 30 min or so to see what the result is? Also, on your sump, are there volume gates between the sections that can be raised or lowered? If there are then lower the last one (between the return chamber and the skim chamber) by gently tapping down on it a little then waiting for several minutes before adjusting again. If none of this works then you have two choices. Increase flow out of the tank or reduce ow into the tank. Me personally, I would i crease flow out of the tank and add a ball valve so you can actually control the drain volume.

 

[sarcophytonIndy]

If you have the return pump as low as it will go, sounds like your only reasonable option is to increase the overflow box capacity. I don't think adding a second overflow is a good idea.

 

[ca1ore]

I'm saying that the third chamber of the sump, where my return pump is located, is consistently running out of water / the water level is dropping rapidly through the day. If I turned off my ATO and ran my return pump at the lowest level right now, that chamber would probably be empty by tomorrow morning or afternoon. The water levels in the other two chambers seem fine - I moved my ATO sensor to the second chamber at one point, just to see if this was actually just evaporation. The ATO probably turned on....once over the course of two days, so it's not that.

What would you recommend?

You’d have to show some pictures. It depends a bit on how your sump is configured, but if it uses traditional baffles then only the final chamber will fluctuate levels based on evaporation. Also, depending on how big the return chamber is relative to the whole system and the sensitivity of the ATO sensor, triggering ten times a day as a result of evaporation isn’t that unusual. As I said before, if the capacity of your pump actually exceeded the HOB overflow then either water would be spilling out of the display or the return chamber level would drop in about a minute.

 

[RobberyinCSharp1824]

Have you tried adding more water to the main display, a little at a time and then waiting 30 min or so to see what the result is? Also, on your sump, are there volume gates between the sections that can be raised or lowered? If there are then lower the last one (between the return chamber and the skim chamber) by gently tapping down on it a little then waiting for several minutes before adjusting again. If none of this works then you have two choices. Increase flow out of the tank or reduce ow into the tank. Me personally, I would i crease flow out of the tank and add a ball valve so you can actually control the drain volume.

The Emerald allows me to adjust the volume gate between chambers 2 and 3. I adjusted it as low as it would go to increase water volume in the return chamber. I've tried topping off water in the DT, but I'm wondering if I just didn't add enough. I considered going as high as the overflow gate would allow and then monitoring the water level over the course of a an hour or two.

If you have the return pump as low as it will go, sounds like your only reasonable option is to increase the overflow box capacity. I don't think adding a second overflow is a good idea.

Thanks; that's good to know!

 

[RobberyinCSharp1824]

You’d have to show some pictures. As I said before, if the capacity of your pump actually exceeded the HOB overflow then either water would be spilling out of the display or the return chamber level would drop in about a minute.

So one of the things I will say is that I don't believe I'm maximizing the overflow box to it's fullest extent. It's been a pain trying to adjust the water levels so the output is at max and also doesn't sound like the hoover dam in my kitchen LOL

 

[Andy69]

Hello!
May sound like a stupid question, are you running the aqualifter when the pump is on? If so, ensure that there is no air leak from the nipple on top of overflow box.
Best of luck.

 

[sarcophytonIndy]

What sized tubing is coming from the overflow to the sump?

 

[RobberyinCSharp1824]

Hello!
May sound like a stupid question, are you running the aqualifter when the pump is on? If so, ensure that there is no air leak from the nipple on top of overflow box.
Best of luck.

Hi Andy! Not a stupid question. I run the aqualifter at all times. Is this doing more harm than good? Should it just be used to maintain the siphon?

What sized tubing is coming from the overflow to the sump?

I believe it's 1.25" diameter flex tubing.

 

[Andy69]

Aqualifter at all times helps prevent air bubbles thereby maximizing flow. I would check for salt creep in the nipple. Mine gets clogged at times and have noticed reduced flow.
Btw, 600gph is pretty plenty for a 120. I’m running barely 400 gph in my 120.

 

[Snoopy 67]

Without a picture it's hard to say, BUT, I think you have to RAISE the baffle so there is MORE water in the return chamber. The lower the water level the less there is for the pump to use before running out.
I also think you are going to have to add more water to the system to allow for the increased volume.

 

[RobberyinCSharp1824]

Btw, 600gph is pretty plenty for a 120. I’m running barely 400 gph in my 120.

Even with the Varios6, which has a max flow return of 1720gph?