What Type of Refugium?!?

[hemicross]

ok everyone, really confused now, i'm going to have my 29g a fish only so all I neec for that is a small skimmer to buy now, but..... I am goign to start making my 75 gallon a coral and fish but my question is right now what type of refugium do I get? Now the guy at the LFS told me everything about the hang on CPR Aquafuge2 the medium one with the built in skimmer, but I am seeing these ones online that go in the storage space under the tank in your stand, can someone explain to me how the water gets down to the fuge and how it gets back up without overflowing the fuge and btw my tank is not drilled or has any sump covers, its just a normal oceanic 75 gallon, Should I get the hang on with skimmer or should I get the bigger refugium for under the tank. I'm so confused

 

[sk8shorty01]

I would definitely go with the under tank one before I went with a HOB. The underneath area will also allow you to use a bigger tank for the fuge. You could go with something like a 20 long. Just get a cheapy used tank from somewhere and you can make your own, they are pretty easy. Just use the pictures on here as guides and you will be fine. There are also some "step by step helps" on this site somewhere.

 

[maxalmon]

The undertank fuges use a HOB (hang on back) overflow or surface skimmer. Because of the way they are designed, once the display tank water level falls below a certain height, they will stop siphoning water and will not overflow your sump. You just have to make sure that the sump is tall enough to handle the extra water volume if the power is turned off or the pumps fail.
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I would go with the undertank fuge, you can make one pretty easy, just google "fuge designs" then purchase a 20-30g tank at LFS, measure for all the walls of the fuge, take a trip to HomeDepot and they will cut either glass or acrylic to the specific size you need, then use some aquarium grade silicone to glue everything in place, you'll save yourself some serious $$$$
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FYI, make sure you measure the return pump and skimmer footprints so that you leave enough room for each. The first one I made, I forgot to do this, spent half a day putting the blasted thing together, then went to install it and neither the skimmer or the return pump would fit because I had made the spaces to narrow.....ARGH...Had to tear it apart and reglue...

 

[am00re34]

i've seen many fuge's/sumps that have input and output lines drilled into the tank. Is this needed or just nice? I am looking to make one out of probably a 30gallon long, but dont have the tools to drill a tank.
how does that work? just place a tube into the sump that runs to your pump?

 

[snakeblitz33]

Well, I shouldn't be the one saying this, but welcome to reefing! Your new 75gal. aquarium is going to be reef as well as fish. You need to decide what kind of reef compatable fish you are going to want, as well as what corals you want to keep. This all has to do with what kind of lights and food you have to buy. The second part of your question or confusion is that for your aquarium, You will have to purchase a "siphon overflow box" or "CPR Backpack". This device will hang on the back of your aquarium. You have to start the siphon manually. It will only siphon water out of your aquarium when the pump is turned on. Due to the design, if your pump turns off, the siphon stops, but does not break. This means that when the pump is turned back on, the water is pushed back into the aquarium and resiphoned. If the siphon breaks, your pump will push water into the aquarium, overflowing it as well as running your sump dry and ultimately burning out your pump.
When choosing a pump, you need to make sure that the pump can push 10x the volume of your tank per hour at 5 foot of head pressure. for a 75gal. aquarium, I would recommend getting a pump called a "mag 9.5" This pump pushes 950gallons at 0 head. I think that for a 75gal. aquarium, a mag 12 would be overkill. (I have a mag 12 on my 90gal.)
As for the plumbing, many people have said that vinyl tubing is the best. I say that it is the best for starters as well. Just cut your tubing, stick it on the return of the pump, and buy a directional U-tube and stick the other end to that. If you know a little about plumbing, I say get a 3/4" PVC pipe, some PVC primer and cement, compatable ball valve and check valve and some elbows. Make sure you also have a union if you want to get your pump out and clean it occasionally.
As for what type of refugium/sump: I say that you would need at a minimum of a 20gal. or you could just buy a rubbermaid that will fit underneath your tank. A refugium is for growing macroalgae, so make sure you have enough money to buy a light for it as well. Happy reefing!

 

[hemicross]

so are the HOB style refugium/skimmer a bad thing, because right now I really am not to sure about the undertank refugium. sounds great and all but i still dont understand how if the pump stops returning the siphon will stop, I understand about how the overflow box part works once it gets low enough it doesnt overflow anymore which means no water for the siphon, but wouldnt the water keep siphoning in the reserve of the overflow until it catches air? how is it you could just turn the return pump back on and everything would run fine again?

 

[maxalmon]

Took me a while to figure that one out as well....
Here is a diagram that may help, kinda along the lines of "what goes up, must comes down - Nothing goes up, nothing comes down" Because the design includes a box on the inside and outside of the tank, each box has a water level that will never fall below a set level, because of gravity, water will only siphon if one area is lower than the other. If the pump goes out, the levels inside the skimmer boxs will be equal and no siphon will occur, but if the pump comes on, the water level in the tank (and the internal skimmer) will rise above the level of the external skimmer and siphoning will start.

 

[maxalmon]

I should have mentioned that the diagram was designed with the pump "Off", once the pump is turned on the water level in the tank would rise and siphoning would start.

 

[maxalmon]

Argh....On the bottom lefthand description, I made a mistake, the riser tubes have to stay below the water level or siphon is broken, (not boxes) thats why the tubes are long and sit well below the slits on the boxs

 

[hemicross]

ok so there are two boxes, one inside and one outside, the one inside has slits for a certain water level, i under stand how that works but how does the tube that connects the two boxes work, is it just sitting inside of the inside and outside box or does it connect to the outside box to the inlet tube for the sump or does it fill the outside sump then the inlet to sump pickup have a different level? i dont know does anyone have a diagram of just the overflow box in detail?

 

[snakeblitz33]

Hmm, I believe that you need to visit www.melevsreef.com and look at the entire website. He has some really good articles and DIY stuff that you could really learn from. www.ozreef.org also has some very helpful information and diagrams.
Technically the two boxes are connected to each other and hang on the back of the aquarium. The U tube is the siphon that siphons water out of the aquarium. To start the siphon, you have to manually start it. Your LFS should be able to tell you how to do this. Make sure however that you get the proper sized pump, or else there might be a build up of bubbles that stops the siphon. (not likely that it will happen, just keep an eye on it)
(The sites listed are not competitors and do not sell anything.)

 

[hemicross]

awesome, great I completely understand it now, meleysreef.com is a great site, Seems fairly simple to build myself except for the overflow box, but wow, thank you so much for the information, now I just need to get a real aquarium stand so I can have space under my tank for a refugium, i know i know, why the hell do I have a 75 gallon tank on a dresser, really risking it, I can't find a decent 75 gallon stand out here with lots of storage space for a reasonable price

 

[hemicross]

ok, well I have decided to build my own aquarium stand, found a DIY page and I can do it, but my question is should I make my own acrylic refugium or should I just buy one, are acrylic sheets cheap?

 

[maxalmon]

I would buy a cheap, 20-30g glass tank and drill it...You can pick them up at LFS for $25 or atleast in Vegas you can.

 

[am00re34]

i have a question on the syphin concept. I understand that once your water level dips below the box level no more water will be moved to the sump. but the return pump will still return so wouldn't it overflow the DT then? or does it fill up the tank and it drains the sump again?
how does this work with tanks that have built-in overflows where water flows in from all levels?

 

[maxalmon]

If the pump stops, the DT water level will drop below the skimmer openings and no more water will drain into the sump, granted there will be a good amount of water that drains into the sump, this is where you have to have a sump large enough to handle the water that drains from the tank. Once the pump comes back on, the level in the DT will rise and start draining back into the sump.

 

[snakeblitz33]

The main point that you might not be understanding is that when the pump is off, the siphon never breaks. It just stops. There's no water passing through the siphon, it's stagnant.
If you make your own acrylic, make sure that you have studied on it. Also, before you begin to make anything that needs to hold water, experiment with a sheet of lexan (acrylic) first before you make your fuge.

 

[am00re34]

so the assumption is the power goes off any everything stops working. what are the chances the siphon stops, but the return pump continues? i know my buddy was messing with his overflow once and broke siphon and his DT started to overflow.
also is it nieve to think making a DIY Sump is as simple as cutting (or have someone else cut) acrylic to your dimensions and glueing the pieces together with silicone?

 

[maxalmon]

Originally Posted by Am00re34
so the assumption is the power goes off any everything stops working. what are the chances the siphon stops, but the return pump continues? i know my buddy was messing with his overflow once and broke siphon and his DT started to overflow.
also is it nieve to think making a DIY Sump is as simple as cutting (or have someone else cut) acrylic to your dimensions and glueing the pieces together with silicone?
I would not try and silcone acrylic, just not strong enough of a bond and it will blow the seams. I tell everyone to use a cheap 20-30g tank.
I hate to say this, but overflowing the DT because he broke the siphon is kinda common sense thing, of course the pump is going to keep pumping the water from the sump into the tank until the sump is empty if the siphon is broke. Nothing is foolproof.

 

[snakeblitz33]

Nothing is fool proof unless it's an internal overflow box
Like anything in this hobby, everything that you do, everything that might happen, will happen. Just try to take preventative measures to keep bad things from happening.
BTW, do NOT use silicone with acrylic. It will not bond on the level that you want it to. Use a FDA recommended Acrylic Solvent. (or appropriate Lexan cement). I do not recommend beginners to this hobby to even think about doing something like this until you have been in the hobby for at least 2 years. (preferably more).
Use a 20gal. Long or a 29gal. They seem to do the best. The sump for one of my 90gal. show tanks is only 12gal. max! Don't worry about not having enough water in a 20gal. sump, it's more then enough!