Jestersix

Frag Tank Setup Questions

MolaMola

Supporting Member
I've done quite a bit of searching in preparation for setting up a lowboy frag tank and now have a bunch of questions but don't want to hijack members' tank journals.
People with bare bottom frag tanks mention maintaining flow to keep the bottom clean. Do you mean so detritus stays suspended and goes out an overflow?
If there is no sand and little rock, where can fish sleep? I've only read about containers of sand for wrasses. And you can't really have/provide a pleasant home for inverts such as shrimp or interesting crabs?
If you have fish, should the whole tank be covered?
I'm stuck between just placing tiles on the bottom and using raised egg crate so fish can swim all around. Would fish just swim around over the forest of frags on tiles?
I wonder if I could make half near a powerhead be bare bottom, then a couple feet of the far end have sand and rock. I do not want sand blowing everywhere, of course.
 
People with bare bottom frag tanks mention maintaining flow to keep the bottom clean. Do you mean so detritus stays suspended and goes out an overflow?
That definitely is one aspect, this however goes hand in hand with lots of flow to do that, you may have a few "dead spots" where you'll notice detritus accumulating but it's super easy to just siphon those area and replace the water.

If there is no sand and little rock, where can fish sleep? I've only read about containers of sand for wrasses. And you can't really have/provide a pleasant home for inverts such as shrimp or interesting crabs?
Fish can sleep between the corals, under the frag racks, where ever really. The only wrasse I would probably put in a frag tank is a six-line or similar type, no sand needed their only job is to deal with pests. That said what do you want to do with the tank? Do you want it as a pure frag growout tank? Do you want it as a display piece? Nothing says you can't can't put small pieces of rock in there as places to grow corals onto, it goes back into the first bit though as you'll make more dead spots. The Lowboy is an interest tank, because it's got a relatively big foot print for it's size, but this comes at the expense of height, which is why it's often used as a frag tank because you don't want corals getting too big in a frag tank (at least height wise).

If you have fish, should the whole tank be covered?
I wouldn't, the size of glass needed to cover may make it difficult to work with. I'd simply choose fish that aren't known for being jumpers

I'm stuck between just placing tiles on the bottom and using raised egg crate so fish can swim all around. Would fish just swim around over the forest of frags on tiles?

Either would work honestly, if you can get ahold of some heavy duty tiles that won't flip and move with flow that works. Jake Adams at Reefbuilders does this with some of their big growout vats (lots of youtube videos on them), granted the tanks are MUCH bigger than Lowboys but the same idea could work. And yeah fish just swim either between corals or above them

I wonder if I could make half near a powerhead be bare bottom, then a couple feet of the far end have sand and rock. I do not want sand blowing everywhere, of course.

Would be a good experiment. Since the tank is 4 feet long if you have power heads only on one side, and don't go too fine with the sand you might just have it all blow on the other side. Would be an interesting experiment... but I'm not going to confirm whether or not it'll work, since sand has a tendency to not behave how you like :D
 
This is how I run my frag tank. It was a 180 that my buddy in LA gave me. I chopped it down to a 48x24x16 but I only run 12” of water in it. Making it approximately 60 gallons. I run cheap 4 sun sun power heads and a sicce. 3 on the back wall and two in a circular pattern on the floor. I don’t run a sand bed. If you don’t algee will grow on your frag plugs. I made my own frag racks from scrap plastic from tap plastics. They are 2 dollars a sheet. I have live rock in there but I normally don’t. If you run egg crate. Get the black one. The white on grows algee. All your fish should have a purpose. I normally have 2 tangs, rabbit, six line, file fish. My frag tank is hooked into my main display. No need to keep parameters for two tanks. Just more work. I cover my openings with the tap plastic covers. All fish jump or splash water. I run the cheap Amazon led that are 60 dollars. They grow sps just fine as I run them close. No need to light the whole aquarium and I can run different par in different areas. They are only 30 watts each. I do run a heater in there but I didn’t for the longest time. All frag controls are from a super old aqua controller jr. From 15 or more years ago.
After I finish qting my fish. I put the fish in there so they can get use to the water chemistry. Less stressful when they reach the DT. I can add weight to the fish in the frag tank too. Hope that helps.
 

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You could make a barrier at one end of the tank with a piece of glass siliconed in place and add a piece of plastic on top due to the sharp edges. There's a word glass places use to describe the finished edge; is not polished, It just doesn't come to mind right now.
As gor the fish having cover, do you plan on using black egg-crate shelving? That gives plenty of room for the fish to hide.
You could use ABS black pipe and serrate it so the egg-crate can fit into the notches and stay put. You may also use ABS cement to bond them.
 
@Coral reefer This will be a standalone tank with no sump. Will have a skimmer sitting in it though. Not for looks!

@sfsuphysics I appreciate all the feedback! I think my students' favorite tank to work in is our 22g bookshelf "frag tank" that is really just a small mixed reef with sand, rock, and a frag rack. The dimensions are awesome: 36x12x12. I didn't realize until I set it up how important tank length is for providing access to kids, even though more hands can lead to more problems. If I am going to include fragging corals with students even once per semester I need more frag tank space. Or set up smaller tanks we have, but each requires all equipment, which is a pain. I also really want to set up more inverts and they are easier to observe in small tanks. The lowboy is awesome! I saw one at Aquarium Concepts in Dublin for turtles or something when I was setting up our first tank and thought it would be cool then but didn't know it was a thing already.

I don't even know about the fish. Just thought I need to plan for algae control. I did not expect that any time we put any coral in our 10g QT algae grows. Guess I do not need fish, but a CUC. I am shocked at how well our new snails and crabs are cleaning up our tanks! I worry about the short lowboy height, since it's hard for me to see fish living in tanks at all.
Doh! I did not think about siphoning out detritus! Much easier in a short tank.

@phc567 Thanks for all the info and details. Never considered color of egg crate. Never saw those little lights - interesting. I have been stressing about lighting for a month already. Also deciding between a big powerhead or multiple small ones.

@xcaret Great ideas to think about.
 
Can't respond to all of them since I'm on mobile, but I would recommend bare bottom vs egg crate. Bubble algae/detritus were WAY easier to clean after I removed the egg crate.
 
I saw a setup with black eggcrate held up above a bare bottom with pvc sections cut to height. Black piping could be found to make a really slick looking setup. I liked how it made the grid for placing the frags with stems on the plugs, and allowed for the fish to hide under the eggcrate.

For the powerhead, you can really make anything work. The issue with large powerheads is right in front of them is very strong, likely too strong for the coral. The good part of them is if you have a clear shot from one side of the tank to the other, you get really good back currents generated from the displacement of the main flow channel. Small powerheads can be placed in strategic locations, but I tend to go with the first strategy of blast a steam into open water, and let the water bouncing off of the walls and rocks make the turbulence. I also like to pulse my main streams to increase turbulence.

While we are thinking out loud, I don't know what types of coral you have the students fragging, but for my "frag" tank, I keep it only with softies do I don't need to worry about water quality nearly as much as the display. Any hard frags go on the rack in my display tank. Plumbing them together would make for easier water quality maintenance, but then you have to plumb your tanks together which may have its own space constraints.
 
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@H2OPlayar Good flow info for me.
Lots to think about... Before pandemic we had two smaller tanks in the process of setup - 14g Biocube for very high light (was to be first SPS attempt) and 20g long to be for low light/softies, gorgonians, shrimps (now I think gorgonians need higher light). Thought they could each house their own frags, too. Then school closed and I emptied them before they were fully set up.
I guess with fresh eyes I looked at the long counter where I had the two smaller tanks and thought one big one would be cool. Now I am back on the fence!
Maybe I will proceed with the lowboy as soft coral/low light. I have on hand multiple old PC lighting or some old Kessils which seem like the wrong shape but would allow for lighting differences across the tank. I think soft corals will need sand. We seem to mostly frag LPS but most do not need tons of light and I think we could keep good enough water quality. I would also like to have a wider variety of softies (but no zoas). I think (aside from algae issues) lots of our stony frags are getting too much light in our current frag tank bc it's only 12" deep.

Nothing can be plumbed to our big tank bc it is in an isolated location, the only open floor space in the room. It is probably better that way bc if one system crashes I have other spaces ready to use.
Feeling better about this based on people's comments and suggestions. I always forget that setting up a tank and its components does not have to be perfect and is not permanent.
 
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