Sump/refugium issues

lmforbis

Well-Known Member
I recently upgraded my 55 gal to a 125 gallon. The tank is up and running. I moved the sump/refugium from my 55 to the 125. Initially, I only had one of the 2 overflows active because my return pump wasn't powerful enough to equal the outflow. I bought a bigger pump which has plenty of power to equal the outflow from the tank but I have run into a couple issues.

1. If I turn both overflows on and the return pump up enough to match it the water flows through the sump like a raging river.

2. There is no room for a bigger skimmer in the existing sump.

3. The sump is too small to deal with a power failure.

I have a lot of space under my tank. Is it possible to plumb a second container, a plastic tote or similar option, to the original fuge that I can have the overflows go into and can contain a bigger skimmer also increassing the total volume by maybe 15 to 20 gallons?
 

bang guy

Moderator
my return pump wasn't powerful enough to equal the outflow.
I don't understand this statement.


#1 - I don't get it.

#2 - Have you considered a skimmer that doesn't have to be in the sump?

#3 - Please describe why it can't deal with a power outage.
 

lmforbis

Well-Known Member
I don't understand this statement.


#1 - I don't get it.

#2 - Have you considered a skimmer that doesn't have to be in the sump?

#3 - Please describe why it can't deal with a power outage.
#1 The flow out of the two built in overflows into the sump was greater than the capacity of my return pump. I purchased a pump that has 1600 gph at 4 foot head height. This does have enough power to equal the flow from the two returns (according to marineland, the flow out of each overflow is 700 gph) but it is moving too fast through the fuge and creating a huge amount of micro bubbles. Right now, I have both the rate of flow out of the tank and the rate of flow back into the tank turned way down to prevent this.

#2 I have looked at external or HOB skimmers which would work fine except for the fact that #3 would still be an issue.

#3 If the power went out, the empty volume of the sump is too small to handle the amount of water that would flow out of the tank which is the volume of both of the overflows, close to 8 gallons, and the water in the tank until it gets below the overflow level. I tested it and there would be a flood.

The potential flood issue is the part that I am most concerned about.
 

bang guy

Moderator
#1 - that really doesn't make sense. The flow rate through the overflows is determined by the return pump. If the pump is sending 100gph to the tank the overflows will send 100gph to the sump, if the pump sends 500gph to the tank then the overflows will send 500gph to the sump.

#2 - HOB would probably be too small for your system. Look at some of the stand-alone skimmers. Hopefully someone here can send some suggestions your way.

#3 - OK, yep, there is a serious issue with that but it's usually not the overflows that cause the problem. It's the siphon from the return. Do you have anti-siphon holes drilled into the return?
 

geridoc

Well-Known Member
Regarding #3: You could put a check valve on the return line so that in the event of a power failure you won't get back-siphoning through this route. If you decide to go this way keep in mind that it seems to be a rule of nature that check valves invariably fail during a blackout. The best solution is bang guy's - anti-siphon holes on the return.
 

lmforbis

Well-Known Member
There are anti syphon holes in the return but the sump is only 15 gallons with maybe 5 gallons of space available for drainage. For peace of mind I want at least twice but preferably three times that amount of empty space in case there is a power outage that causes the pump to go out.
 

pegasus

Well-Known Member
I recently upgraded my 55 gal to a 125 gallon. The tank is up and running. I moved the sump/refugium from my 55 to the 125. Initially, I only had one of the 2 overflows active because my return pump wasn't powerful enough to equal the outflow. I bought a bigger pump which has plenty of power to equal the outflow from the tank but I have run into a couple issues.

1. If I turn both overflows on and the return pump up enough to match it the water flows through the sump like a raging river.

2. There is no room for a bigger skimmer in the existing sump.

3. The sump is too small to deal with a power failure.

I have a lot of space under my tank. Is it possible to plumb a second container, a plastic tote or similar option, to the original fuge that I can have the overflows go into and can contain a bigger skimmer also increassing the total volume by maybe 15 to 20 gallons?
1. The valves on the overflows are not used to set the flow going into the sump. Those valve are only to be used to stop the slurping noise created by siphoning in the overflow tubes. You only close them enough to stop the slurping, and that's where they should stay. The flow through the sump is controlled by the return pump. Open the overflows as much as you can without them slurping, then use the valve on the pump to set the desired flow.

2. Get a bigger sump, or an external skimmer.

3. Get a bigger sump that will hold the extra volume. Adding a check valve or anti-siphon hole on the return line will help only if the end(s) of the return line (inside tank) is below the level of the overflows. If the return line end(s) is higher, no action is necessary since it will stop siphoning once it breaks the surface of the water... as the overflows continue to drain. I'd check on the position of the return line in relation to the overflows before making any modifications. Just my 2c...
 

pegasus

Well-Known Member
There are anti syphon holes in the return but the sump is only 15 gallons with maybe 5 gallons of space available for drainage. For peace of mind I want at least twice but preferably three times that amount of empty space in case there is a power outage that causes the pump to go out.
I think you need a bigger sump... lol! I have a 30 gallon refugium, and it handles the water for my 125, my 40B, and a remote deep sand bed when the power's cut. Heck, it might even hold a couple or three more gallons!
 

silverado61

Well-Known Member
How far below the tanks water line is the anti siphon hole drilled? It only needs to be about 1/2in below the over flow vent. You may have it drilled too low.
 
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lmforbis

Well-Known Member
The anti siphon hole was already in the plumbing kit I got with the tank from Marineland. The pipe comes up from the bottom of the tank and makes a 90 degree turn before it gets attached to the tube that goes to the tank. The hole is in the inside of the 90 degree turn.
 

lmforbis

Well-Known Member
I'm starting to think I'll buy a 29 gal and build a new sump. That way I don't have to worry about floods. I can size the chambers to fit a skimmer and still have a good 10 gallons of just in case space.
 
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