Rookie, New Build, Rubble or Sand?

[CastAway]

I'm a newbie, new build, and trying to decide, sand bed or rubble? have a 150g display tank, 60g sump with 25g refugium area. Refugium has a <em>flow through </em>design, and I'm worried high flow will blow sand out. My goal with the fuge, in my ignorance, is pods and fauna for a SPS centric tank. I've been reading, but have not found anything really definitive, so, I thought I'd ask for input. Be gentle.

 

[nivram]

That's a great looking sump. Not to confuse you even further, but if your goal is to run chaeto in the refugium, you do not necessarily need to run either. The benefit to not running either sand or rubble, it will be easier for you to spot and clean detritus.

 

[revhtree Verified Admin]

Welcome to R2R! To be clear you are talking about for your refugium right?

 

[CastAway]

Yes, I'm talking about live rock rubble and/or sand for the refugium, pictured in this thread. The middle area of the sump is the refugium area. There's room for 5" of sand in the bottom (if I can keep from blowing it out) and/or live rock rubble. If I use rubble I intend to use removable baskets for easier cleaning. I was really hoping for as large of a variety of macro algae that will grow, most hoping for reds as I read their more beneficial. I've consider using both sand and rubble but am concerned I might affect the advection by placing rubble on the sand and end up with some potentially bad areas.

 

[Palting]

I have a 150 gallon SPS dominated reef tank with a 50 gallon sump/refugium running for 3 years. Just to establish my credentials somewhat . You'll need about 1000-1500gph flow running through the sump, and I would use medium grain sand or rubble for the refugium. Definitely NOT sugar fine sand.

 

[CastAway]

Thanks Palting! I'll be running two Iwaki 70's, one of which is plumbed with a bypass around the refugium, and the other of which does not have to be run at all - more-or-less a back-up or supplemental pump. So, Flow could be 0 to 3000gph through the center area. My design basis and expectation is 1500gph through the refugium area. Can one expect the same kind of fauna to live in the medium grain sand bed as opposed to what might live in the finer grain? My goal (in my ignorance) with the sand bed is the fauna that would be continuously provided to the display.

 

[Palting]

Not sure about the fauna in fine sand vs coarse sand. What I can say, however, is that I have medium grain substrate in both the DT and the refugium, maybe slightly larger in the refugium, and I have 2 dragonettes and a 6 line as well as a dotty back all fat and happy eating off whatever fauna grows from there. The SPS are also growing like gangbusters, but not sure if that's just because of the light and water and less because of the fauna. Rotifers and pods will also thrive within the macroalgae bush, eating off any phyto that grow there. You can also build what some call a "pod condo". Essentially it's small to medium rocks piled up into a tower in one corner of the refugium where there is good flow. Talking about flow, I am a little concerned about your sump/refugium design. Both inlet and outlet from the refugium are in the lower third, potentially leaving the upper 2/3rd with low flow. I would built a rock wall across the middle to anchor some of the macroalage variety you're considering, like red gracilaria. This will dissipate that flow upwards and around it, as well as act as a habitat for fauna and as part of your liverock system.

BTW, where are you putting your skimmer, or are you going skimmerless?

 

[CastAway]

If I had it to do all over again, I'd do it differently. Learn as you go, you know. I am concerned about laminar flow through the refugium also. I thought I might divert the flow upwards on the side where the water enters, either by rock or a piece of acrylic. It should be pretty easy. I wonder if I could not layer some different sand, fine on bottom, medium and small rubble on top? I have an Aqua-C EV240 skimmer with an Iwaki 55 to drive it. I've read mixed reviews on it, and again, if I had it to do all over again, I might choose another. Until it fails to do the job, it'll have to do. It'll go into the sump, on the larger side in the picture. I just got my stand home tonight, and will be posting some more pics in my gallery.

 

[CastAway]

If I had it to do all over again, I'd do it differently. Learn as you go, you know. I <em>am</em> concerned about laminar flow through the refugium also. I thought I might divert the flow upwards on the side where the water enters, either by rock or a piece of acrylic. It should be pretty easy. I wonder if I could not <em>layer</em> some different sand, fine on bottom, medium and small rubble on top?&nbsp;I have an Aqua-C EV240 skimmer with an Iwaki 55 to drive it. I've read mixed reviews on it, and again, if I had it to do all over again, I might choose another. Until it fails to do the job, it'll have to do. It'll go into the sump, on the larger side in the picture. I just got my stand home tonight, and will be posting some more pics in my gallery. Love love love your tank btw Palting. Awesome! What I aspire to. :bigsmile:

 

[CastAway]

I did mis-calculate on the flow. I feel like such a dumb a55. Long story short, I'm selling one of two Iwaki MD70's I bought, and, have plugged one of the two bulkheads in my sump. Total flow will be no greater than 1500gph, and, I do have a valved fuge bypass line that ought to cut the flow by not quite half. Anyway, I've committed to include the sand bed at this point. Any recommendation on a particular brand and size? Any advantage in mixing in some quantity of mud in the very bottom?

 

[mcarroll]

Flow for a sump with the goal of filtration only needs to be 2-4x the display volume, or 300-600 gph. 400-800 if you wanna include the refugium volume too. You'd have no issues with sand moving in this range, not to mention a much smaller pump and electric bill. I hate to say it, but I think I'd sell both md70's and get something smaller.

The place you want the mega flow is in the display with the corals, and the best way to get that is with a good set of powerheads. Something powerful and directional like the Tunze 6105 (with or without a wavebox) would be a good place to start for a long, narrow tank like a 150 as it's flow pattern is longer. (Most other powerheads have a very wide, stubby flow pattern...better for stubby tanks like cubes.)

If you choose to put some kind of media down there - no matter if it's rubble or sand - it should be a in a removable tray or bucket. Sand can be worse than rubble for catching detritus. Personally I would use neither as you simply don't need it when you have live rock in the display. You will not lack in Nitrate processing power....PO4 is what you will be worrying about and macro algae will do more to help you there.

I hope this helps!

-Matt

 

[CastAway]

Thanks mcarroll! It does help. I will indeed find and use some trays or baskets for the sand and/or rubble. I've heard of that, and frankly, had forgotten. Great idea.