Sump design advice

[Stblindtiger]

Hello everyone. I currently have a 75 Gallon tank that I am switching over from a canister filter to a sump.

I just added a 15 gallon sump to the tank (30 gallon total capacity). The tank isn’t drilled, so I added an overflow (CS50 siphon up to 300 GPH). The overflow is plumbed with 3/4” PVC that drains into the first section of the sump with the PVC ending 1 inch below the water line. I cemented the PVC into the bottom of the overflow, and added a Union below the overflow in case I need to take it apart. I also didn’t seal the lower 45° angle piece and piece that goes into the sump because I plan on adding a plexiglass top to the sump to try and minimize evaporation, but I cemented everything else in place. I also bought an aqua lifter pump (Koller 3 GPH) to attach to the overflow box to prevent losing a siphon in case of a power outage. I also added a shut off valve to this pipe prior to it draining into the sump, and assessable under the tank.

The sump has three chambers, with baffles leading to each chamber. The first chamber has the drain from the overflow (plumbing discussed above), as well as a protein skimmer. The second chamber will eventually hold some Chaeto (anyone know of a good online source of clean Chaeto? Algaebarn and a few other sites I looked at did not have any in stock???), as well as two heaters, and some live rock. The third chamber has a return pump (Hygger 24 V Saltwater pump with controller).

The return line from the pump is plumbed with 3/4 ID flexible hose. I added a shutoff valve, and plan to add an inline check valve but I’m waiting for the check valve to arrive on Friday.

The pumps will be plugged into a battery backup so that in case of a power failure the pumps will still run and I shouldn’t lose the siphon.

Anyone see anything wrong with this setup? Anything I should be worried about? I currently do not have any aqua sock filters. The only filters I have are the skimmer, the live rock and filter media in the second chamber, eventually some Chaeto in the second chamber too, and then some black foam filter pads stuck in the baffles between the second chamber and the third chamber that holds the return pump. Do I need anything else? In all I have about 75 lbs of live rock in the tank and sump, and two 5 gallon Home Depot buckets of sand in the display tank(no sand in sump).

 

[Stblindtiger]

Sorry…. The total capacity of the sump is 20 gallons. Not 30.

I got everything running but I’m terrified to let it run without having the check valve installed on the return line. I turned everything back off and closed the valves. Going to play around with it again tomorrow after work. Don’t feel comfortable leaving it on unsupervised overnight and when I’m at work.

Anyone have any tips on timing the return pump with the rate the water flows in from the overflow? I was playing around with the valves restricting the flow into the sump from the display tank, and also trying to adjust the speed on the return pump as well as the valve returning back to the display tank. I need to read up on this pump too….

 

[PotatoPig]

.

The return line from the pump is plumbed with 3/4 ID flexible hose. I added a shutoff valve, and plan to add an inline check valve but I’m waiting for the check valve to arrive on Friday.

Strongly recommend setting up your water so that the maximum that can siphon back into your tank (and don’t trust the drilled hole method) is less than the spare capacity in the tank when the pump is running.

At the other end - try to make sure the maximum capacity of the section the return pump is in is less than the remainder capacity in the tank, in case your drain fails your will be limited to buying a new pump.

If the check valve fails - blockage, algae, slime, snail, whatever and you don’t have a failsafe backup you’re looking at thousands of dollars, potentially tens of thousands of dollars, of damage to your floors.

Maybe you’ve done this already and the check valve is a convenience thing, in which case disregard the above.

Also suggest placing the sump in a waterproof lined basin if at all possible. Even if it’s just 6mil plastic sheeting attached to the bottom of the frame. Gives some spare capacity in case of emergency and mitigates risks associated with splashing.

 

[Stblindtiger]

.


Strongly recommend setting up your water so that the maximum that can siphon back into your tank (and don’t trust the drilled hole method) is less than the spare capacity in the tank when the pump is running.

At the other end - try to make sure the maximum capacity of the section the return pump is in is less than the remainder capacity in the tank, in case your drain fails your will be limited to buying a new pump.

If the check valve fails - blockage, algae, slime, snail, whatever and you don’t have a failsafe backup you’re looking at thousands of dollars, potentially tens of thousands of dollars, of damage to your floors.

Maybe you’ve done this already and the check valve is a convenience thing, in which case disregard the above.

Also suggest placing the sump in a waterproof lined basin if at all possible. Even if it’s just 6mil plastic sheeting attached to the bottom of the frame. Gives some spare capacity in case of emergency and mitigates risks associated with splashing.

Thank you for replying! I definitely had my return line too deep into the tank. I raised the return line so the bottom is only 1/2 inch deep into the Display tank water. That should minimize the amount of water that can back flow back into the sump!

Thanks again!!!!

 

[PotatoPig]

Thank you for replying! I definitely had my return line too deep into the tank. I raised the return line so the bottom is only 1/2 inch deep into the Display tank water. That should minimize the amount of water that can back flow back into the sump!

Thanks again!!!!

No worries - I set my first tank up a couple months ago and had a very very narrow escape from a siphon and too deep return, was only *just* saved by having a basin that filled to the brim. My end result was to raise the return up same as yours is now - just below the water line.

 

[fishmonkey]

Yea always make sure your return pump is high enough so if there’s a back siphon you have enough space so it doesn’t overflow your sump.

I’m not the biggest fan of chaeto. It’s better than an algae scrubber but it’s just another thing you have to balance. If an algae scrubber stops growing algae due to low nitrates and phosphates then it’s not a big deal. Also it has significantly less light spill. The light spill can start growing algae all over your sump especially near the skimmer.

I had an issue with my tank and basically all my chaeto died out. Now I have some knitting screens in my sump and hoping algae takes hold there over places I don’t want it. The algae mess isn’t too bad I’m considering taking out the refugium light and going with a drop scrubber from Santa Monica filtration. Do some research before you fully commit to one thing.

 

[Stblindtiger]

I’m not the biggest fan of chaeto. It’s better than an algae scrubber but it’s just another thing you have to balance. If an algae scrubber stops growing algae due to low nitrates and phosphates then it’s not a big deal. Also it has significantly less light spill. The light spill can start growing algae all over your sump especially near the skimmer.

I had an issue with my tank and basically all my chaeto died out. Now I have some knitting screens in my sump and hoping algae takes hold there over places I don’t want it. The algae mess isn’t too bad I’m considering taking out the refugium light and going with a drop scrubber from Santa Monica filtration. Do some research before you fully commit to one thing.

Ha…. I thought I was done spending money for equipment on this tank, and now you just introduced me to an algae scrubber.l! My wife is going to kill me!

That will have to be on my wish list for now though.

 

[fishmonkey]

Ha…. I thought I was done spending money for equipment on this tank, and now you just introduced me to an algae scrubber.l! My wife is going to kill me!

That will have to be on my wish list for now though.

Yea just look into it first. Patience is so key in this hobby it’s unbelievable. Some people don’t even run a refugium or scrubber and do just fine. It might not be what you want and you don’t want to waste money on stuff.

There’s a wealth of information out there. You can also make a diy scrubber if you want and there are ways to prevent light spill with chaeto.

 

[Stblindtiger]

I’ve had the sump running steady for about 5 hours now without any issues. I made sure that the overflow inlet and the return line duckbill were only about a half inch to 3/4 inches below the water line, then I turned off all the pumps and left the shut off valves open to make sure the sump could hold all the extra water in the tank that would drain out if there was a power outage.

I also played around with how open the valves were so that the water level in the sump and overflow remained pretty stable. The level of water in the overflow box seems to rise and fall a little bit every once in a while, but it always seems to regulate itself without any issues. Little bubbles are appearing in the baffles of the overflow box, but the aqua lifter seems to be taking care of it and there is never any bubbles bigger than a millimeter(maybe smaller even), so I’m not worried about losing the siphon on the box.

Water is flowing fine through the baffles and three sections. The skimmer isn’t producing bubbles up into the collection cup no matter how I adjust the water intake/air intake/pump speed though. It is sitting in enough water according to the manufacturer specs, so I’m hoping it’s just because I did about a 50% water change and there isn’t much protein to skim out right now? I’m hoping as it sits in there longer, it will start collecting something into the collection cup.

The level in the last chamber is below the last baffle(I.e. not back flowing into the middle chamber), but might be a little high right now?? It has stayed at a pretty stable level for a while now though, so I’m hoping it’s okay.

It’s getting late, but everything has remained pretty stable for a few hours now. I feel pretty confident it should be okay, especially since I made sure the sump could hold any extra water that might siphon back in there. Going to bed will still be pretty interesting tonight though!

Attaching pictures of what it looks like right now. Please excuse the cloudy water (I had to drain the tank, and remove all the rocks and sand in order to add the sump under the tank and in the cabinet.), and a little bit of sloppy wiring. I need to straighten all those out tomorrow.

What do you think? Am I missing anything?

 

[wil-yuhm]

Anyone have any tips on timing the return pump with the rate the water flows in from the overflow? I was playing around with the valves restricting the flow into the sump from the display tank, and also trying to adjust the speed on the return pump as well as the valve returning back to the display tank. I need to read up on this pump too….

I suppose an active design might incorporate a sump/float/switch or if not a switch some sort of varying resistor to a pump capable of operating at varying voltages.
Float out to pump voltage maximum @ high water level
Float out to pump voltage low or kill @ low water level.

 

[fishmonkey]

I’ve had the sump running steady for about 5 hours now without any issues. I made sure that the overflow inlet and the return line duckbill were only about a half inch to 3/4 inches below the water line, then I turned off all the pumps and left the shut off valves open to make sure the sump could hold all the extra water in the tank that would drain out if there was a power outage.

I also played around with how open the valves were so that the water level in the sump and overflow remained pretty stable. The level of water in the overflow box seems to rise and fall a little bit every once in a while, but it always seems to regulate itself without any issues. Little bubbles are appearing in the baffles of the overflow box, but the aqua lifter seems to be taking care of it and there is never any bubbles bigger than a millimeter(maybe smaller even), so I’m not worried about losing the siphon on the box.

Water is flowing fine through the baffles and three sections. The skimmer isn’t producing bubbles up into the collection cup no matter how I adjust the water intake/air intake/pump speed though. It is sitting in enough water according to the manufacturer specs, so I’m hoping it’s just because I did about a 50% water change and there isn’t much protein to skim out right now? I’m hoping as it sits in there longer, it will start collecting something into the collection cup.

The level in the last chamber is below the last baffle(I.e. not back flowing into the middle chamber), but might be a little high right now?? It has stayed at a pretty stable level for a while now though, so I’m hoping it’s okay.

It’s getting late, but everything has remained pretty stable for a few hours now. I feel pretty confident it should be okay, especially since I made sure the sump could hold any extra water that might siphon back in there. Going to bed will still be pretty interesting tonight though!

Attaching pictures of what it looks like right now. Please excuse the cloudy water (I had to drain the tank, and remove all the rocks and sand in order to add the sump under the tank and in the cabinet.), and a little bit of sloppy wiring. I need to straighten all those out tomorrow.

What do you think? Am I missing anything?

Skimmers need some time to break in. I think it’s about a week or so. I assume you read the instructions and there is enough water in the skimmer for it to work properly.

The last chamber is where the return pump sits so that’s where the water will fluctuate first. If your return pumps are pushing more water than can be sent down the overflow, the level in that last chamber will go down and water in your tank will go up.

Set the auto top off level to what ever level you want it to be. In that last chamber. I’f you don’t have an auto top off you’re gonna have to mark the level and refill it to that mark every day with fresh water or your salinity will go up. Salt doesn’t evaporate but water does. There are diy auto top offs if you don’t have one. I like this one https://www.bulkreefsupply.com/aqua...XcAffBZDVoF0iM91QHZb5paM5-9cXPYUaAtxyEALw_wcB but there are other options. From a soda bottle and to a 230 dollar tunze.