How to calculate flow in a Refugium?

[Grav]

I'm setting up a refuge above my display (back room) the idea is to pump watter up from the sump, into the fuge and gravity feed back to the display sending pods and other critters in LIVE. The goal is to have a Mandarin so as many live pods as possible. Lighting is a 10k 96w quad PC. I think I've got it plummed pretty well, and shoudn't have bubbles in the tank, but this remains to be seen when a pump is added.

 

Sorry, nuff bragging, here are my questions:

 

How to calculate flow? Based on tank size, fuge size, lighting, more is better... what? Main display is 150g, total fuge water volume will be 18 to 20g. Does something in the range of 150 to 200g / hour sound right?

 

How about a small wet-dry section. YES I know NO2 factory... but then it would hit the fuge getting consumed... Right? Prolly a silly idea, but it was my idea.

 

I was THINKING about using a timer, one of those 15 min on 15 min off timmers to add a bit of wave making action in the display. Also thinking the "off time" would let the pods get lazy and get closer to the over flow. Is this a bad idea? Would O2 levels drop killing macro and pods without flow into the fuge? Would the pump (I'm thinking Mag 5 or 7 right now) burn out?

 

I currently have a 5g bucket built quickly as a temporary fuge that I think will stay. This draws water by grav(ity) from the main tank and drains into the sump... then getting pumped back to the main tank (IE no unchopped pods) I want the larger "above main display" fuge to produce the most pods possible, and nutrent export is good too (I'm thinking Cheato) on top of a LS bed. I'm thinking the lower fuge (smaller but more acccessable) will house my new mangrove (cuz it's fun) grow a food sorce for the future Tang(s) as well as complement whatever is in the larger fuge (I'm thinking Calerpa) LR rubble no sand.

 

Anything I'm not thinking about?

 

Anything I'm over thinking?

 

Thanks in advance all.

 

Phil

[Lee Stearns]

Grav -- sounds most cool- I do not think the Mag pumps like being turned on and off- I would consider some type of surge/flushing device that dumps the water into the main tank when it builds to a certain level- that way you can keep your flow constant to the upper pod fuge- figure the size of the fuge and the flow of a small pump with the head pressure calculated and you could figure how often it would flush- I have seen some of these designs on RC and thier DIY page- might do a search- Man what an awesome tank that 150G island is.

On Pod fuges I do not know the nutrient sump effectiveness. My experience has been that you will want to feed them a bit- If you are a heavy main tank feeder then I think they will reproduce well- I have two pepermint shrimp in my fuge and while I know they do a great job on any aptasia. I think they predate on the pods- I also see them hang out by the flow when the tank is fed so I am assuming they are waiting to catch a meal and that there is little to feed upon in the fuge- The best pod production in my experience is when feeding phyto plankton, which is why I would love to add some form of phyto growth drip system but am worried about dumping the nutirents that feed the phyto into the tank before they are consumed. If you grow batch Phyto you do not have that worry. Grow or feed phyto and you will have pods!

Good luck with getting this all together and if you need a hand playing with it at some point let me know-

Regards, Lee

[Grav]

Thanks Lee, for the feedback and kind words.

 

Bruce Carlson spoke at my 1st WAMAS meeting and made a point of giving credit for the surge device that bears his name to someone else... can't remember who. I guess it wasn't really his idea, he just had better marketing. I seriously considered the "flush" surge devices but with the goal of sending live pods into the rock structure (not across the surface of the tank) bubbles will be troubles.

 

The little fuge is running for what, a month now, and already I see loads and loads of life in there. I may soon pull some of the 4 snails out to leave more film alge for the tiny snails (that are getting bigger) and other critters. I wont be putting any preditors in fuge unless someone gives me a really good reason.

 

I think yer right, timmer idea on the pump is out.

 

I like your phyto drip idea. I'm thinking a mini phyto reactor with a nutreient drip into the phyto, which then drips into the fuge. Any extra nutrents get taken up by the chaeto, some phyto feeds pods, pods and some phyto goes to main tank feeding everyone else.

 

What about flow rate, anyone? I know we say 15-25+ turns / hr in the main tank but what is the right flow rate in a fuge?

[Guest D33rex]

It may not matter to you, but using a yellower light, like a 6500 makes the algae grow much faster in the refuge in my opinion.

[GaryL]

i use the par 38 bulb from home depot..... its about a 5200k seems to work great for me. about $20 bucks and had a light setup for the fuge. it runs very cool too. i added it to strip light grow lights.

[craby]

In my experience, you want good flow rate in your fuge because if the water moves too slow, you could get Cyano bacteria (sp). One way around this is to stay w/ the 150-200 gph & add a power head.

[Grav]

The PC bulbs / ballasts I have are used, old and free. Each with 8+ months on them, I figure the older they get the better for alge growth. Eddie has 3 yr old PC bulbs on his 125 fuge and if it's good nuff for him, it's good nuff for me.

 

Actually I'd rather have more flow into (and out of) the fuge, as this will directly result in increased flow in the tank. Durring testing my overflows were able to handle about 2200 gal / hr and they are only doing about 1200-1300 now so I know that won't restrict me.

 

Remember this fuge while made from a 24g tub will only hold about 18 gal so 200 gph is already 10 turns an hour. So is the suggestion more like 400-500 gph in the bigger fuge? Or even more?

 

Thanks again all.

 

phil