how big?

[steve_karen]

How big of a refugium do I need for a 55Gal? I was planning on using a 10gal. Half would be the fuge and the other half would be for the return? I have a separate sump for my protein skimmer. It's not enough room in that sump for a fuge. Am I on the right track?

[AZDesertRat]

10 g won't give you much room. You have to account for evaporation and for power outages so you need some capacity in the sump for both. I have a 30 G on my 100 and wish it was twice that size. I would see if a 20 or even 30 will fit your application if it were me. Remember your sump will probably only be 1/2 to 2/3 full max so you still have room for backsiphonage when the power goes off for any reason. Otherwise you will have a flood on your hands.

[COONREEF]

I am getting ready to build a 20g fuge for my 55. I already have a 10g for my UV and skimmer. Thinking about putting them all in the same space. Will post plans tonight.

[jpfelix]

i have a 55 and a 20l on my 29. to answer your question---i'd go as big as you can fit.

[danielcherian]

Not to jack your thread or anything, but in the event of a power outage, how would you prevent back siphoning from your sump return? How do you guys deal with this situation? Afterall, your sump can only hold so much water. I understand that if you're at home, you can always close a valve and be fine, but when not at home what do/would you do? Are there ball valves that prevent this? If so, any links? Are there one way valves?

EDIT: Upon doing some research, I found that using a "check valve" will help maintain flow in only one direction (thereby preventing back siphoning). I found this link to a PVC Check Valve (http://www.watertanks.com/category/138/). Again, sorry for jacking your thread! :)

[AZDesertRat]

You can install a check valve, but thats not really advisable because gunk collects on the valve seat and it will invariably fail or at least seep back when you need them. The best way is to drill small holes just below the waterline on your returns so they create a siphon break when the holes are exposed when the water level drops in the tank. Once you have a sump installed you need to fill your tank to its operating level and then shut the power off. Once the water quits flowing back mark the difference between the normal level and that level on your sump with something permanent. Then always leave yourself that much room when you fill your sump so you will never have an overflow. In my case I always leave 4 inches of freeboard in my 30 G sump.

[Charlie Davidson]

Steve-Karen, you are at the right place to find the answer!! I believe your answer-- is-- buy the bigest you can! if you can-- pipe in a 200g to your tank!! (over kill- but gets message across)
Keep reading, there are few easy answers in this hobby!

BTW, watch out- (IMHO) do not buy spring operated check valves- most rust in salt water, and they reduce flow ALOT!!!