# Umm...HELP? Trying to build a refugium sump. I'm stuck on stupid...



## crazyfishlady

Warning: This is the most stupid post you will probably read today! hahah! Hope you learn from our mistakes...

To begin this story...I have purchased a 72 bowfront that I've been trying to set up for the past two months. I have done much research on the saltwater filters and in my opinion, the refugium sump seems the most natural and best filter out there. Instead of purchasing a unit, I decided to get "crafty" and make one myself. I bought a 20 gallon long glass tank from Petsmart, 5- 12"x12" acrylic pieces, a 600gph quiet-flo CPR overflow box, an 850gph return pump, a one-way valve for the return tubing, clamps, more tubing, and so on...

We began cutting the pieces of acrylic so the water flows through a filter media, through the bio-balls, underneath the first baffle and over the top of the next into the refugium then, into the return pump area. (I will post pictures soon) Everything looked great so far. I decided to use foam weather stripping around the pieces of acrylic and fit the baffles in using pressure. Seemed like a good idea at the time, at least I could move the baffles if I didin't like where they were. As it turns out the pressure seals don't work all that well...the water is evenly distributed through the whole sump...Lots of trial and error here but, this is only the beginning...hope you learn from our dumb errors...

We live in a mobile home, (it is actually a lot nicer than any apartment I have ever been in, heheh) anywho, the floor isn't as stable as you would think and I believe I set the tank up directly over a support beam... Let's see 72 gallons, 8lbs a gallon and live rock and sand? Yeah, that's pretty heavy. The tank seems to lean forward a bit. Right now it's filled to the top with water and about another 100lbs of live rock and sand, oh, and two eels. When we step anywhere directly infront of the tank it seems to sway a little bit...making me VERY nervous...we're gonna have to put some more support underneath the mobile home and perhaps a board to distribute the weight underneath the tank.

Getting back to the Refugium Sump...I filled it with water, started the siphon in the overflow box and turned on the pump. Other than the faulty seals between the baffles, everything seemed to be working alright. We then cut the power to the pump. Little did we realize the siphon from the overflow box didn't break for a while because I didn't figure out where the water line needed to end so we didn't wind up overflowing on the floor. hahahha!!! So I hear running water and realize the sump is overflowing with water from the overflow box! ::Crap, this tank is gonna fall through the floor or tip over on me!:: So I try to absorb as much water as I can, break the siphon to the overflow box, and turn on the pump. Well...we left that on too long and then the actual aquarium started overflowing! OMG! We're idiots! hahhaha! So we drain some water back into the sump, kill the pump, and break the siphon. We think everything is suffice and leave the room.

AGAIN, we hear water rushing out! We run back into the room and for whatever reason the one way valve hooked up in the return tubing to the aquarium isn't working! AGAIN, the sump is overflowing! We clean everything up and just give up for the night...Everything that can go wrong was going wrong...

We set up the weight bench so it's propped up against the tank so we could get a goodnight's rest without the worry the tank was going to tip. Now I need to make some sealed baffles, figure out how to break the seal on the siphon in a power outage or figure out where the water level needs to be, make sure the seal doesn't break in a non-power outage, and figure out what to do about the one way valve that was suppose to stop the back flow of water...UUUGH! This is soooo frustrating!:chair:

Any advice would be MUCH appreciated. As long as it's not mocking my intelligence, hahahah!:withstup: Thank you.


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## SBDTHUR

Pretty sure they have things that will break the siphon if the water gets past a certain point. Someone else will probably help you with that. But that's what I'd be most worried about. If there was a power outage and the tank would drain onto the floor. Second option would be get a backup generator..  But that would be too much work.


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## Guest

Well, you should make sure your sump is big enough to hold all of the water that the overflow will drain before the water level in the aquarium is low enough to break the siphon. I'm sure there is some way to fix it without getting a larger sump, but I think that'd be your best option...

Also, the aquarium overflowed because your pump is pumping at a higher GPH rating than your overflow is draining. To prevent an overflow in the aquarium, your pump should pump at exactly the same GPH as the overflow, or less. Unless your pump has an adjustable flow, you might have to get a new one.


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## crazyfishlady

Well, the pump has to pump straight up about 5' to the fish tank which subtracts the gph from the pump. In all my research it says to buy a pump that has a higher gph than the overflow box. The tank overflowed the second time because I purposely broke the siphon on the overflow box. I just need to figure out where my water levels need to be and most likely purchase a ball valve.


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## Guest

Sorry, I was thinking you meant 850 GPH after head loss for some reason. I meant that your pump should pump less than the overflow box after head loss.


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## s13

If the pump is still pumping too much, throw some elbows in the mix and that should cut down on the GPH as well.


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## karazy

and for the baffles, use aquarium silicone. thats what tanks are sealed with.
dont use regular silicone, because it will leech bad things into th water
use one that says it can be used for aquariums.

and also, you need to figure out some way to make sure that if the power goes out, and the siphon keeps going(which it will until the water level is below the box in the tank) that the water siphoned out can be held in your sump.
all i can think off is building a new sump with a bigger tank


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## s13

Aquarium Silicone will not adhere to acrylic. Some people still use it though... Don't be surprised if the baffle gives.


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## Guest

I've used it with decent results, but not all are successful with it. Its worth a try though, I think.

And you don't need aquarium silicone, just make sure its 100% silicone with no mildewcides added.


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## crazyfishlady

Thank you very much for all your great advice!


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## jones57742

crazyfishlady said:


> Thank you very much for all your great advice!


cfl:

I was on the road today and your 1st post was subsequent to my leaving Austin: I am also not sure what most of the other posts are saying.


*Head Loss*
You should be able to locate on the Internet a head/discharge curve for your pump similar to this one which is applicable to my pump.


*Sump Overflow*
_Part One - Return to the Sump_
From your monologue I do not believe that your tank is drilled and the return from the tank to the sump functions via a siphon.
Drill a small hole in the siphon tube an inch or so below the lowest typical operating water surface in the tank. When the pump is not operative the water surface in the tank will subside below the hole, the suction air will break the siphon and the sump will cease filling.
The volume of water in the tank above the hole should be less than the volume of air in the sump above the typical operating water surface.
_Part Two - Back-flow Through the Pump Discharge Line_
Placing a back-flow preventer in the pump discharge will theoretically solve this problem but these back-flow preventers (or at least all that I have tried) are just a disaster waiting to happen.
When the pump is not operative they will hang in the open position and the sump will flood or, for whatever reason, will close when the pump is operative and the pump will burn up.
A better solution is to place the discharge orifices in the tank such that when the pump is not operative the volume of of water in the tank above the discharge orifices is less than the volume of air in the sump above the typical sump operating water surface.


*Typical Operation*
As best as I can tell something is really wrong here. The height of water in the sump should only be controlled by the total volume of water in the tank and the sump.
The overflow weir in the tank and the return line to the sump should be sized such that only a minor increase in head (like 1/2" to 3/4") in the tank's water surface is necessary for the capacity of these features to equal the discharge from the pump.


TR


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## k-dawg-

Ok pictures of your overflow box/ sump would be a great help first of all.

1st As you found out you have to make sure there is enough extra volume in the sump to handle the excess water in the overflow box. Easiest solution to me? cut down the sump baffle to maybe 8x12". Is this a 20G high or a 20G (the dimensions are different for each. 

2nd 850gph is a lot through such a small sump even with a bit of head loss factored in. Even if your overflow can handle that much microbubbles will be a nightmare...trust me, originally I tried to run 800gph through my 20G sump and it didnt work out as planned. A good rule of thumb is 2-4x tank volume per hour through the sump, so between ~150-300gph.

3rd The check valve ("Back flow preventers" "one way valve" etc..) should probably be removed, as you've learned they can and will fail. A simple way to prevent the return line from start to siphon is to drill a small hole in it somewhere near the surface allowing air to get in and breaking the siphon. or as Jones suggest keep the outlet of the return close enough to the surface to allow air in when the pump is turned off.

4th 100% silicone will hold sump baffles in fine, its not ideal but baffles have very little pressure on them so its really not that big an issue. GE 100% Silicone Type I (not type II) without mold inhibitor will work fine and can be found at most home depot's.

5th Pictures! =P Hope this helps, best of luck to you, I know what your going through during the construction of my sump I probably spilled a combine 30G of water on the floor but in the end it will be worth it I promise.


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