Need help with my sump

[Vinylmation]

Hello MFK's. I've had my tank running for 3 months. I've had freshwater fish most of my life but first time with a sump. The issue I'm having is I'll have my sump perfectly balanced (drain/pumps) then randomly my display tank starts to overflow. I'm not sure why this is happening. I end up rebalancing it, it's good for a few days to a week then happens again. At first I thought maybe the bio balls were clogging the drain but I added some egg crate to keep the bio balls off the drain and it still happens. Now I'm thinking it has to be the pumps? They're maybe randomly powering up to 100% and causing the overflow? I need help fixing this issue please. My wife is not happy with the random overflows.

Pumps 2 are Jebao DCQ-6000 even though controller says DCQ-6500.

 

[Midwater]

Is the overflow on your main tank getting blocked up? Is the overflow big/wide enough to take the flow of two 6500 pumps?

Post some pictures of your main tank and overflow.

 

[Vinylmation]

Is the overflow on your main tank getting blocked up? Is the overflow big/wide enough to take the flow of two 6500 pumps?

Post some pictures of your main tank and overflow.

No blockage on the drain weir. I have a full syphon. If I have drain fully open the pumps aren't strong enough to overcome water draining to sump

 

[duanes]

What size piping are the overflow lines to the sump.
For two 6000 gph pump flow rates the plumbing should be at least 2" pipe diameter per overflow line, and appropriately sized bulkheads.
If the tank is drilled, the overflow pipe size to the sump should normally double the size of influent line, or the influent will overwhelm the overflow, and flood the tank to the floor.
On my 1500 gph flow to the sump, I use two 1" lines and they just have enough bore diameter to keep up with 1500 gph pump output flow.

 

[Sassafras]

Wait a minute, when you said that your drain was in full siphon, I assumed you have a Herbie or Beananimal setup. when you say, " If I have drain fully open the pumps aren't strong enough to overcome water draining to sump", that sounds like there may be only one drain line that you are controlling with a valve. If that is the case, you will continue to be at risk for periodic overflows. The amount of water draining to the sump should be controlled by the volume that the pumps are pushing. You balance that flow with the valve on your full siphon drain and the secondary drain(s) pick up any slack. Any increase in flow will then drain through your secondary drain (Herbie) or secondary, and if needed, emergency drains (Beananimal). Tell us more about your drain lines. Something ain't right!

 

[duanes]

Ahh siphon,
does that mean your tank isn't drilled? and you are using over the rim U-Tube siphons or overflows?
If the tank is not drilled , all it takes is a bubble or two, a snail or even a leaf or two, to get stuck, and siphon can be interrupted, ending up with water on the floor, especially with 2 strong pumps.

 

[puffers4puffers]

What size piping are the overflow lines to the sump.
For two 6000 gph pump flow rates the plumbing should be at least 2" pipe diameter per overflow line, and appropriately sized bulkheads.
If the tank is drilled, the overflow pipe size to the sump should normally double the size of influent line, or the influent will overwhelm the overflow, and flood the tank to the floor.
On my 1500 gph flow to the sump, I use two 1" lines and they just have enough bore diameter to keep up with 1500 gph pump output flow.

View attachment 1542216

View attachment 1542217

View attachment 1542218

In stead of 90 degree elbows in the first pic, I would have used a “T” to allow for air escape
bubbles will reduce flow and possibly result in overflow

 

[Vinylmation]

My tank has 1 2" drain and 2 3/4" return lines. The pumps are running 1" PVC from the pumps to the bottom of aquarium then reduced to 3/4". The aquarium is drilled on the bottom. Full syphon on the bottom of the aquarium, all I have is a strainer, I have no durso, herbie, bean animal etc. I purchased this used so I had no say in the sizing and number of holes on the bottom of the aquarium. I had the aquarium balanced at 70% power so now I'm experimenting and having the tank balanced at 100% power. To balance the drainage, I have a gate valve.

 

[Sassafras]

Very risky living controlling flow by throttling flow on the drain line. General rule of thumb is to always control flow by adjusting the pump output. The only way to safely have a valve on a drain line is to have a backup drain line. That is how the Herbie and Beananimal designs function. You refer to a "full siphon", but I don't see how there can be a siphon unless you force the drain pipe to run full by closing the valve on the drain and raising the water level inside the overflow tower above the drain. That would be a certain recipe for disaster. Does your 2" drain pipe come up through the bottom back center of the tank and form a standpipe inside the overflow tower or does the strainer you mention sit right on the bottom of the tank?

If I understand your setup correctly, you will continue to battle flow variations and random overflows unless you open the drain 100% and control flow by adjusting your pump output. The water level in the sump, voltage changes, biofilm buildup on the inside of your pipes will all cause changes in flow over time and it is impossible to always be there at the right time to adjust the valve on your drain. Of course, opening your drain will result in noise. I would replace the strainer with a standpipe, possibly look into a Durso standpipe to quiet things down. I'm no expert on Dursos, I run Beananimal overflows myself, but if you are limited to a single drain pipe a Durso may be your best option.

If I am misunderstanding your setup, the above advice may be moot. Trying to understand and be helpful. I would hate to be on pins and needles waiting for the next overflow.

 

[Backfromthedead]

It sounds to me like youre having trouble maintaining the full siphon.

With a 2" drain, those 2x 6500 LPH(not GPH) pumps will not be close to pumping enough water to match a wide open 2" full siphon drain (several thousand GPH depending on head pressure). I would first turn the pumps down to minimum power, then set the gate valve on the drain to around 1/4 or maybe 1/3 open. Then dial both pumps up incrementally, waiting for a couple minutes every time to see if youre making any progress. You should eventually get to a point where the drain is completely submerged and is holding the siphon without belching air. If its not, check a couple things:

-The drains outlets in the sump should always be submerged a bit. If theyre not the drain will slurp air there and disrupt the siphon.

-The drain inlet, in the overflow, may be too high, which may allow it to slurp air and break siphon. I would position the inlet about 2-3" below the teeth on the weir, and cap with a strainer if you dont have one already.

All of this is kinda shady because you need an emergency drain. If you want to run full siphon drains an emergency drain is non negotiable imo, even with an oversized drain i guarantee it will clog at some point which means house flood. I would personally never run any sump without at least one emergency drain, preferably one for each drain.