Above-Tank Chaeto Refugium for a Nano

heisenberg

New member
Hi everyone. First thread here, hope it gets some conversation going. :)

I have a modest reef in a BC29 and I want to expand my volume to add an above-tank refugium for Chaeto growth/nutrient export, and pod reproduction. I would normally think to place it below in the stand, but the tank isn't drilled and I don't like to rely on U-tube based siphons. Above-tank also has the added benefit of letting water and pods gently flow back into the display without a pump in the way, and it's highly visible for observation.

I usually like to research and complete DIY projects on my own but I have been toying with this idea for a while and want to cover all my bases. This seems like the kind of project that if it goes badly, it goes really badly- and floods my living room (although the volume involved here doesn't even touch some of the catastrophes I've read about).

That's why I came here for ideas and advice- anyone ever done one of these before? Any thoughts, opinions, pitfalls, etc?

Here's a VERY rough image that I just whipped up in MS Paint to give an visual idea of what I'm talking about:

fugeplan.jpg


And here's the plan so far, off the top of my head:


This fuge is going to be roughly 10 gallons. At first I was going to try a glass tank but I don't want to drill it; the glass on the cheaper, smaller tanks is really thin and looks fragile. Going with acrylic seems like a much better idea. I'll probably get an acrylic tank from GlassCages since I can't find anything on craigslist after a month+ of searching.

There will be two sets of baffles, sized by me and cut by TAP plastics. I'll drill my own holes for send and return with a specialty bit for acrylic; one hole on each end of the tank. Water pumped up from the display will flow up into the refugium through a bulkhead, route above the water level in chamber 1 with PVC, and then be directed downward. I'll drill a small hole in the PVC elbow above the water line for siphon prevention. From the picture above, am I even really going to need 2 sets of baffles? The first set only really serves to prevent catastrophe if the bulkhead or power+siphon prevention fails and it begins to drain back into the tank.

The refugium overflow will be routed similarly; from the bulkhead a 90 degree elbow will point upwards where the overflow will take in water and determine the equilibrium water level during pump operation. How noisy should I expect this to be? It'll be a low volume going through the overflow but I've heard some of these can be pretty loud.

Are pre- and post-bulkhead ball valves a good idea, or not really necessary?

I'll use a strainer on both ends of the overflow path so that snails and other larger critters don't get stuck in the line and impede flow- which could cause a flood. I don't want to use too fine a spacing, though, because one of the major points of this fuge is to provide a source of amphipods for my fish to munch on so they have to be able to get through. I might remove bits of the strainer to allow for larger particles/objects to pass, but nothing large enough to cause a problem.

Water level changes in the third part of the fuge (past the second set of baffles) will determine how much overflow goes into my main tank in the event of a power outage. I'm planning on making this third section as small as the overflow's PVC tubing will allow so long as I can still get hands in there for construction and maintenance. That way I only end up sending volume equal to [height difference] times [surface area] back to the display in a worst-case scenario. I want to avoid any possible cause of flooding... can you spot one that I've overlooked?

A MaxiJet 1200 in chamber 2 of my BC29 sending up ~1.5 feet to the refugium should suffice. Recommendations on alternative pumps? I'll be using clear vinyl tubing past the bulkheads (connected to hosebarb fittings) and want to make sure that the size on the overflow side can handle whatever is pumped up to it. Any ideas on how to appropriately size the overflow tubing? Will 1/2in be enough, or possibly even overkill?

I'm going to drill a new hole for a bulkhead in the plastic false-wall of the display tank while the water is low during a regular WC. It will be going next to the stock pump return in chamber 3. Any advice for drilling this hole? The tank is stocked and running, but during a water change the level goes down low enough that I can quickly drill this without bothering the inhabitants. Will little bits of plastic that may get into the water be a source of trouble?

The overflow from the fuge will pass through the back of the hood and then be plumbed to this false-wall bulkhead, thereby sending all return water from the fuge into the display area. That means the flow from the MJ in chamber 2 of my BC will act in unison with my stock pump to effectively double the flow through my physical filtration, which right now consists of hand-cut pieces of filter floss under the overflow from display tank chamber 1 to chamber 2 that I change bi-daily.

No miracle mud or DSB for now- just a bunch of Chaeto and maybe some LR rubble. I'll just get some simple PC lighting for the macro growth. For the rubble, I'll fill a couple of those green plastic strawberry baskets with it to provide plenty of space for critters to live in without trapping a lot of detritus. Any thoughts regarding the LR rubble?

My Chaetomorpha will be free-floating, but I definitely want to come up with some way of preventing most if not all of it from spilling over into the overflow section of the refugium. Any ideas? Should I have notches cut (or holes drilled) in the first piece of my second set of baffles to slightly strain the water passing towards the overflow?

I'll be sure to document progress in this thread when it comes time to build.
 
the first set of baffles is not needed at all, if you can justify them I may see something I didn't before, the last pair is alright though, and the bubble trap on the second part isn't necessary either. There is no pump to chop up any bubbles, the water will just go through the overflow like normal, where it mixes with air anyways. Cutting teeth isn't a bad idea but if it will cost more then 10$ just buy a sheet of egg crate and save the hassle, you will only need 1/75 of the sheet but you can save some for later.

when building it a shallow tank is better unless you plan on lighting all sides, any macro that isn't lit will die and dump nutes back into the tank.

2vajaqr.jpg
 
I did this years ago on a nano tank... I had a shelf above the tank so thought why not. I used nothing more than a critter keeper (cheap acrylic fish tank/bug house) that you buy at Petco. I drilled the critter keeper with a 1/2' inlet and a 3/4" drain. No baffles or anything even remotely fancy. Just had the plastic strainer that comes with the bulkhead in it. I feed it via a mini jet pump that was positioned in the nano (5.5) gallons to the point if for whatever reason my drain line my get clogged the pump would just be sucking air. Sooooo.... zero chance of overflowing the fuge. My return line fed into the lid of an HOB filter. No dursos, stockmans, herbies.... nothing. Simple clear tubing up, simple clear tubing down. Very quiet and functioned beautifully.

Steve

(if I ever scrounge up an old zip drive I've got some pics I could post or send you, that is if you even needed them.... very, very simple set up)
 
I agree that the baffles aren't necessary and that there should be a back-up drain positioned a little higher. Instead of the baffles I might use the glass to instead make an inner overflow box (3) and position the pvc L piece down instead of up.
 
Does the back-up drain go through the same bulkhead? I.E. is it two strainers that are plumbed together out to the display, or are there two independent drain tubes?


I know 1/2" tubing will take the water from the MaxiJet 1200 without a problem. Will 3/4" bulkheads and vinyl tubing handle the overflow alright?
 
We have this currently set up on out 29gal Biocube, the only difference is we pump through the chiller and them to the refugium. The refugium is a 10 gal glass tank which we had drilled at the local fish store, we only drilled for the overflow. There are no baffles installed, have live rock and chaeto. There is approximately 3 feet to refuguim and we are using a 1200gph pump(not sure of the brand). We used plastic tubing with barbs as well.

What we did to prevent a flood was cement the PVC on the inside of the tank up to the point where the strainer attaches. We will only loss a couple of inches in the refugium and we always make sure the sump in the BC in not full. Haven't had an issue yet and it has been 3 years. Works really well, helps with water parameters, and it is not noisy at all. The tank is actually in our bedroom about 3 feet from the bed.
 
Megalodon, OnemorBeer, any specific reason for the dual bulkheads/drains? I can imagine some unlikely combination of factors causing one to get clogged (maybe a vermetid infestation combined with algae growth?) but is it worth the additional trouble of having another drain, hole, bulkhead, etc? What are you imagining could clog the drain? I don't doubt your advice, just curious.

Is the second drain at a higher level similar to the second drain in a sink?

Having the 90 degree elbow pointed downward eliminates some or all of the noise? I thought having it upward would provide some amount of surface skimming for the refugium while having it downward may encourage protein, dust, etc to collect on the surface.

I'm also considering your suggestions about foregoing the first set of baffles, and possibly replacing the second baffles with a small overflow box. It's about the same amount of material and I could pre-fabricate it before cementing it into the inside of the tank. It'll increase the total volume of the system compared to the baffles sectioning off a whole swath of tank area, but I'm not 100% sure I'll go that route yet. Eliminating the first set of baffles seems plausible if I can guarantee that the seals on the PVC are watertight. I'm definitely going to be cementing the PVC up to the strainer. I don't want any leaks below the water line at all.

The big obstacle right now is actually designing and building a custom stand for this. I'm going to do 2x4's and plywood, and design it to store some other fish equipment (water jugs, Vortech controller, etc).


Tasha6, thanks for the wisdom and experience. 1200gph is a lot of flow- is that due to the head pressure from the 3 feet height? It makes the MaxiJet 1200 seem puny in comparison.
 
Tasha6, thanks for the wisdom and experience. 1200gph is a lot of flow- is that due to the head pressure from the 3 feet height? It makes the MaxiJet 1200 seem puny in comparison.[/QUOTE]

We went with such a high flow because we pump to the chiller, which is sitting on the floor, up to the refugium. I probably misspoke when I said 3 feet as that is the distance between the top of the refugium and where the pump is located. Total head pressure is probably 6 to 7 feet. It can definitely can be done and works well.

As far as what we used for a shelf, we went to Lowe's or home depot and bought a 3 foot solid shelf, reminds of the shelving used in some closets other than the fact that is is solid, and then mounted it with 3 large brackets(the type that are rated for a couple of hundred pounds) into the studs.
 
Megalodon, OnemorBeer, any specific reason for the dual bulkheads/drains? I can imagine some unlikely combination of factors causing one to get clogged (maybe a vermetid infestation combined with algae growth?) but is it worth the additional trouble of having another drain, hole, bulkhead, etc? What are you imagining could clog the drain? I don't doubt your advice, just curious.
It's just extra precaution in the event there is a clog. Think of it as insurance.

Is the second drain at a higher level similar to the second drain in a sink?
Two ways of doing it, 1) having both bulkheads at the same level but having one elbow down for the first drain, and the second with the PVC elbow up, or 2) just simply having one bulkhead higher than the other.

Having the 90 degree elbow pointed downward eliminates some or all of the noise? I thought having it upward would provide some amount of surface skimming for the refugium while having it downward may encourage protein, dust, etc to collect on the surface.
If you did that like I said you can use that glass saved on the baffles by making an interior overflow box for the surface skimming. For that you'd basically make a box around the drains low enough water can overflow into it.
 
I'm toying with the idea of at least one set of baffles so that I can retain this tank in the future and use it as a below-tank sump/fuge. If I have one set of baffles in place with enough room for a return pump behind them, I can reuse this little tank in more ways than one.


Anyone have any idea how effective a DSB/lots of LR would be in this little tank for a 29G with significant biomass? Doesn't it take several months just to present any benefit at all? Takes time for the anaerobic bacteria levels to rise, right?
 
Anyone have any idea how effective a DSB/lots of LR would be in this little tank for a 29G with significant biomass? Doesn't it take several months just to present any benefit at all? Takes time for the anaerobic bacteria levels to rise, right?
It would be effective and worth doing. Yes it takes a while for anaerobic bacteria to grow but be patient and hang in there.
 
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