plumbing assistance ...

[rwdandald]

I am changing refugium some. I want the refugium to gravity feed back into display instead of sump which has brought up two minor engineering issues which I am unsure of. (FYI 150 gallon display , 35 gallon refugium)

1. How much flow would be reasonable for refugium? My understanding is a moderately low flow is best for nutrient export. I am thinkiig of using a smallish powerhead (MJ 1200) to move water from display into refugium ( it is only moving it 12 inches over and up 3 inches ) with 1/2 id flexible tubing. The drain back is with a 1 1/2" id pvc pipe drilled in top 2 inches of refugium. Would this be an adequate water exchange?

2. My concern is if something really bad happened to refugium (broke, drain clogged - etc) how would I set in a safety to prevent PH from draining display onto floor?

-Reuben

[puter]

Hi Reuben -

Briefly: 1. Low flow is good. 2. Have the intake up high in the display tank.

[Guy]

1 - I've quite a bit of experimenting with this and an 8X+ turnover rate in the refugium seems to grow the most sand bed infauna but the water leaving the refugium needs to be taken from the top to allow the detritus to be trapped in the refugium.

6X turnover appears to be good for Caulerpa (Racemosa and Serulata were tested) and Chaetomorpha. 8X turnover gave identical results.

2 - Strongly consider a second overflow on the refugium. Refugium overflows are prone to clogging by snails, algae, etc. Set the second overflow higher so it starts only if the first is clogged.

I like the idea of setting the powerhead high in the display. Good tip.

3 - Why are you going to all this effort?

Guy

[S Helinski]

I have experiance with this, using a powerhead. I have a 15 high under one of my tanks, and above and to the left of it, there is a "3/4 gallon" "critter cage" made of plastic. there is a maxijet 1200 in the sump, hard plumbed to pump water up about 26 inches and over about 10 inches. It then goes down about 3 inches, inside of the refugium made from the critter cage. The critter cage fuge has a makeshift bulkhead with a strainer fit into it. It overflows via a jammed piece of 1.5" ID flexible hose into the 15 high sump. This is not a Great way to do this, but it works well in the tight space under a 54 corner tank.

The Maxijet 1200 works fine for this fuge, and can be plumbed a good distance w/o restricting the flow entirely.

About the overflowing, you could build your fuge on a slant, like with a dishwashing mat, that would drain water right back into your display. It might look ugly though. But you could hide it, if you wanted.

Good luck.

Steve

[rwdandald]

Thanks for the ideas/tips all.

Have the intake up high in the display tank

simple and makes sense - I am considering a float switch in fuge as well- I actually have a dual float switch left from a failed auto top off I was playing with which could shut off PH if water got too high or low (though I am less than impressed with performance of float switches in general as being somewhat unreliable).

The Maxijet 1200 works fine for this fuge, and can be plumbed a good distance w/o restricting the flow entirely

Thanks - glad it is at least feasible.

Strongly consider a second overflow on the refugium. Refugium overflows are prone to clogging by snails, algae, etc. Set the second overflow higher so it starts only if the first is clogged.

yes - I had originally thought of two overflows but am less than thrilled about doing the drilling - If the first drill attempt goes easily I will do that.

Why are you going to all this effort?

very good question. I had a 55 I was using as a refugium with overflows going into sump. I used a mag 350 canister to move water from sump to refugium and returned back to sump with overflow box. I am going to use the 55 as a sump for my wifes tank though that I will be setting up in the next month or two so I needed a new refugium and I got a custom 35 galllon acrylic on ebay for $35 to use for this. I have read in some places that the other benefits of the fuge ( pods for natural live fish food) are lost by sending them through impellar of pumps to get into display. I tested this theory by examination of sump (plenty of pods visible by looking ) and then put a nylon sock over each of my returns from sump to see what was coming out. After six hours no live visible pods in sock but the same process on the overflows from main or refugium left lots of live wiggling pods in sock ...so it seems to me there is some veracity to idea that pumps tend to mangle the pods. Based on this very unscientific reasoning I decided since I had to do a new fuge anyway I would go with a gravity flow into display. As to whethher it is worth it or not I have no idea but my thinking is "why not?"

[Guy]

Every pump is different and I've seen that powerheads definately chew pods. I've done a bit of experimenting with pumps though and they really don't do much damage. a few percent of the pods get damaged but those are the ones that get eaten right away I recently had a 1" Clownfish go through an Iwaki 55 without damage.

Just food for thought.

[rwdandald]

Originally posted by Guy
Every pump is different and I've seen that powerheads definately chew pods. I've done a bit of experimenting with pumps though and they really don't do much damage. a few percent of the pods get damaged but those are the ones that get eaten right away I recently had a 1" Clownfish go through an Iwaki 55 without damage.

Just food for thought.

My hermits would love it if I sent a clown though my mag return - a new feeding method.........clowns must be like cats - 9 lives....

[Kent E]

Whoa! a fish through a pump-unbelievable!

[josepha]

Guy,
Do you have other pumps comming from that mongo refugium? and if so what are they? Do you find pod getting into your tank from down there? Also, have you found any Crashing or soaking of the DSB and if not why do you think it's not happening? Sorry for all the questions, a lot on my mind as I restructure the new 300Gal.
joe

[Guy]

I have two pressure rated Iwaki pumps going to the display in parallel. Series would give more water flow but not as good of a redundant system.

Plenty of pods get through. I've put filter bags over the returns and the only animals I've noticed damage on are the larger Amphipods and only a few of those. The Chromis hang out in the current eating them though so I'd imagine the only ones that survive come through at night.

I have not yet experiences the DSB wasting. I believe it's because of the amount of macro algae I harvest. I'm no scientist though so I just guessing.

I'm slowly switching from Caulerpa to a combination of Chaetomorpha and Red Sea Xenia for exporting nutrients. Time will tell I guess.