Tank /sump issue

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Aquarium Advice Newbie
May 5, 2019
Hello, I’m a newbie to the site and saltwater tanks.
I currently have an 85 gallon coffee table fish tank. It is viewed from 5 of the 6 sides. I’ve had it running for almost 2 years with power heads and live rock as my filtration and doing water changes weekly. After losing a bunch of fish, I decided to clean house and start fresh but with a huge twist/project. I spent weeks research on what I needed and drawings of how to do this and move forward. I took the plunge and purchased a bunch of equipment. So I’ll explain what I did. And then explain the issue at hand. But from what I’ve been researching. I can’t seem to find out where I’m going wrong. So hopefully someone here has experienced this.

So what I did for this project was. Starting with the R/O system was empty a coat closet about 8 feet away from my display tank. In that closet is where everything is going. My r/o system is installed in there with a water line running under the floor as well as a drain line for the r/o system. The r/o produces and the discharge water gets dumped into a condensate pump and that gets shot back to the kitchen sink where it’s tied into the drain below. The food r/o then gets pumped up and across the attic in an insulated covering to my office closet into a 20gallon pail. That Pail has a high and low sensor as well as a float switch and a leak detector on the floor. Once that Pail is filled I shut the r/o off and turn the ATO pump side on and then that pump pumps it back up and across back to the coat closet (where all the equipment is) and puts it into a 2.5 gallon eshoppes tank where that is gravity fed into my sump to maintain water level.

There also is a 10 gallon hospital tank stand alone. That’s where I stored the live sand for the project. And the 20 gallon Pail is where the live rock got stored until I was ready to put back into the display tank.

So now I emptied the display tank cleaned it all out. The tank has 4 corner towers already installed. 3 wet towers and 1 dry tower for electric. I then flipped the tank and drilled out 2 of the wet tower from the bottom (after contacting the manufacturer to make sure it wasn’t tempered glass) and installed a bulkhead in each using the gaskets and aquarium silicone. I then moved the carpet cut the floor open . I ran 1 1/2 flex pvc under the floor to the coat closet. Capes everything off. Waited 3 days for everything to dry and then pressure tested it for 48 hours. No leaks. I was good to close everything up. I also installed leak doctores under the tank at each bulkhead. The pipes come into the closet and reduce to 1”. From there it goes to a ball valve then a gate valve and into the sump. The return pipe leaves at 1” to a gate valve to a check valve to a ball valve back reduces back to 1 1/2 under the floor to the tank where it comes into a 1” bulk and then reduces down to two (2) half inch duckbill outlets.
So that’s the plumbing end.

There are 2 pumps. A pump to send the water to the sump. And a pump to return back to the display tank. This is where the problem arises. Because the coffee table tank is ground level and the sump is ground level with the plumbing running down then back up. There needs to be a pump to pump back to sump. Where almost all water going to dumps are gravity fed. Mine isn’t. The problem is trying to balance the water coming to the sump along with the water retuning to the display tank. I have matching pumps. They are uniclife dep-4000 with controllable speeds. I just installed the gate valves bc I heard they are finer tuning. But still at the same spot. I’m really at a loss right now.

I also set up a skimmer with a heater in the sump and purchased the Neptune apex which is wall mounted / control center in the same closet. So I went a little nuts. Lol

I know this was a long tread I’m apologize. But really want to make this work but really stuck now. Any advice would be greatly appreciated.

Thanks in advance!


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Welp... this is certainly a first... I'm no expert, I'd say you definitely want gravity doing the work on one end.. ideally the draining. Can you lift the table/tank to facilitate this? I run a sump backwards, pump draws water out and gravity returns. I get no added flow but it keeps water moving through the sump. If you have 2 pumps working in tandem and one fails... it's going to be a big problem somewhere in the house. I wouldnt be able to sleep at night.
Yea I kinda figured not many people have heard of something like this. I’m hoping that if this ever works out, I’ll be in the process of making a water overflow pan underneath the sump with a drain so Incase one pump does fail and overflows the sump it will overflow into the pan and drain outside the house. The return pump will never be able to overflow the tank bc the amount of water that’s in the “return” tower part of the sump is manybe 2 gallons and that won’t be enough to overflow the display tank.
I appreciate the reply, thank you.
I'm no plumber, but can't you just adjust the valves until flow is even? You said you have both ball valves and gate valves on both of them.
That’s what I thought I could do. And the pumps are adjustable speeds also. But some some reason this is where the problem lies. I have both pumps set to 100% and then adjust the gate valves leaving the ball valves in the full open position and only use them for on/off only where as the gate valves are supposedly for fine tuning, which is what I’m using. I’ve got it down to approximately a 1/16 - 1/32 of an inch turn and still won’t balance. I’ve spent a few hours trying to get it. But no luck. I don’t know if it’s air that’s being pulled in from the overflow and running in the line and causing the fluctuation or maybe a pump having internal issues. Just really confused.
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