Has Anyone Tried a "Rubble Bottom?"

[Don424]

Originally posted by algaeguy
Don and Whaledriver:

Thanks again for the sweet ideas...Who would have thought that the humble UG filter can be a valuable ally in a 21st centrury setup? It's cool to see this kind of creative thinking!

What I've been doing so far is using large pieces of Tonga slab rock placed directly on the bottom, with pieces loosely stacked on top of others, yet leaving plenty of "void" space in between. With my Streams blasting a cycle of 30%-100% throughout the tank, and the Sequence doing its magic, I have only seen detritus accumulation in one easy-to-siphon area. Surprisingly(?), I have seen no detectible nitrate or phosphate thus far.

I think if I were doing it over again, I'd try the UGF plate idea. This may be a fantastic way to maintain such alternative systems for the long run.

Keep the ideas coming!

Scott

Scott

For that zone that's accumulating some detritus, any chance a spray bar across the bottom of the tank would help or a maxijet powerhead with that Hydor rotating flow head on it?

Look....even if you go into the tank once every week of 2 with a powerhead and blow the stuff up into the water column, that should be fine. Very short maintenance time......should take all of a minute or two.
I sent you an email to get pictures:

[Don424]

Originally posted by lillibirdy
Don, how will the the bottom of layer of rubble grow anaerobic bacteria? I thought it wasn't condensed enough to shut out oxygen? In my own tank, I think the areas under my rubble that is CC will surely grow some, and if I stop stirring CC behind rocks.

But won't the actual rubble layer itself get to much oxygen to allow that type of oxygen starved bacteria? Maybe I am confused again, wouldn't surprise me none...lol.

Lillibirdy

I was referring to Whaledriver's suggestion/idea that if Algaeguy used a UGF plate with the rubble on top and sequencing reverse ugf flow for only an hour a day. Maintenance flow would be in the tank the rest of the time from other circulating pumps. Since the water under the ugf would be semi stagnant/very low flow lets say for 22 hours or so, there's a good chance that the anerobic would have a chance to build under the plate and seed into the bottom of the rubble.

The same principal and theory would apply to your tank with CC also. You're not confused......It didn't come out of my mouth the right way

[Whaledriver]

I think that with the large rock type rubble you would never go anerobic and wouldnt wat to anyway. The daily didturbance of the water would allow the funky water to mix with the fish water. I would have some very large rock, like 20-40 pound pieces to give the fish a place to hide.

On of the things I was thinking would be to use an Oceanic tank with the corner overflows. I would have a section in front of the overflows on each end blocked off with a 3-6 inch piece of glass. This would let me put a deepsand bed in the roughly one foot square created on each end of the tank. The rest would have a rubble bottom with a undergravel filter plate under it. I think this would give me the best of both worlds

[Paul B]

I would love to see how this mixed rubble, temporary fast, temp. slow rerverse UG filtered tank works out. I have my feelings about it but since I am an inventer I love controversial endeavours.
Good luck.
Paul

[lillibirdy]

My LFS guy just rolled his eyes and told me since the only purpose of an UGF is to make nitrates, and that it will do so whether it's reversed or not, that I should take it out, (and the CC). I hate it when someone I have to deal with, thinks I am a big ol doofus... I am aiming at mainly fish and by Spring maybe a few LPS and softies, (might experiment with an easy SPS). Is Nitrates of 12 really so bad? I am aiming lower, with refugium and some other ideas, but was just so discouraged, glad I didn't mention the big rubble pile in the middle.... I just hate telling anyone my set up......

[Paul B]

lillibirdy, I told you were going to get that from people. Especially people who don't have a tank for very long.
Paul

[algaeguy]

Yep...don't be discouraged. You have a vision and a plan- a unique one...Stick to it!

Scott

[Don424]

Originally posted by jda
Saw this thread kinda late, but I use a rubble bottom on my FOWLR. About 50% Carib Sea Sea Floor and about 50% hammered-up live rock. I started this because I did not want the fish to move all the substrate around. The hunks are from M&M size all the way up to Jawbreaker/Golf-Ball size.

It gets a nice layer of coralline on it and looks pretty good. It also houses a LOT of mini stars, worms and pods. I don't vacuum it and my NO3 is about 1 and PO4 about 0.

Sure some food ends up in there, but the worms and fauna take care of it. You would be suprised how the fish can "blow" and all the food comes back up for them to eat. Even the eels can get to it.

The triggers and puffers like to find the occasional worm or star out in the open as a real treat. At night, there are pods like crazy all over the place.

Where do you get pods and worms from?

[H20ENG]

How about a modded maxijet with prop, or a tunze feeding the UGF plate. That would get a lot of upwelling going on.
You could also have a surge bucket feed the thing.

Great thread, BTW!

[Whaledriver]

If the rubble is large enough junk wont collect and nitrates should not be a problem.

You could just put 2 powerheads on the inlets to the undergravel plate. One would be small to keep it areobic. The other would run an hour or two a day and be larger to surge out all the silt and junk.

When you talk to someone about this idea just dont use the word "undergravel". The word just brings up the stone age of saltwater

[algaeguy]

I've noticed some interesting things about my rubble bottom so far (it's been expanding slowly every week as I accumulate more appropriate pieces). First is that there really has been no accumulation of detritus in the gaps in the rubble. Second has been the remarkable growth of some "cryptic" organisms, such as sponges. Another cool thing that I have found is that some little "bits and pieces" of SPS frags and zooanthid polyps that may have broken off through my own carelessness have fallen into the rubble area and have began to encrust! I think that I have really strong flow down there, and have actually decided to secure some frags deliberately down there, similar to just_dave.

Finally, the best thing I've noticed is that my nitrate and phosphate are still at undetectable levels almost 6 months into this! I really think that it's all about husbandry, flow and a really good skimmer!

Scott

[Whaledriver]

This might be a great idea for a grow out tank with a shelf system. Stuff ( little "bits and pieces" of SPS frags and zooanthid polyps) can collect on the rocks and can then be moved to larger rocks for grow out.

[algaeguy]

EXACTLY!

In fact, I've seen this type of set up at a number of different coral propagation facilities. Not only does it make it easier to remove corals to give/trade with other hobbyists, but it looks pretty darned cool, too!

I'm looking forward to this rubble bottom expanding and filling out.

Although I didn't do this- the ideas for the UGF on the bottom are very interesting and make lots of sense!

Scott

[Whaledriver]

?golf ball size?

[Mike O'Brien]

Here is a shot of my 10 gallon bare bottom rubble zone tank, it is dedicated to a mandarin. It really can be an effective in tank refugium for pod's.

[algaeguy]

Awesome!

I'll bet that the pod poulation and other microfauna is amazing. Im hoping that my 225 grows up to be just like your 10!

Thanks for sharing!

Scott

[Don424]

Originally posted by Mike O'Brien
Here is a shot of my 10 gallon bare bottom rubble zone tank, it is dedicated to a mandarin. It really can be an effective in tank refugium for pod's.

I gotta tell you.......after seeing your tank and algaeguy, I am so tempted to go UGF/reverse flow and full rubble floor with a few showpiece of LR. I am really liking the look.........I've seen rubble zones when snorkeling and the tanks look like what I've seen........ and with a high reverse flow I think there will be little to no problems with nitrate, phosphate and consequentially little or no algae......man this is tough.

[algaeguy]

I'm lovin' this!

Scott

[Mike O'Brien]

Thank's guy's. The fish is happily fed. There are plenty of different pod's in there, and I use a sponge prefilter in there as well to increase the surface area for them.

[Chicago]

do you really want the sponge filter? looks like pleanty of rock... is the sponge filter adding nitrate to the system. ?

[Mike O'Brien]

It's just the sponge, pod's live in it. Did I say I did 70% WC's a week. What are nitrates?

[Chicago]

sorry didnt catch that about the sponge

[aurorafish]

I basically have had a 90 gallon rubble bottom for the last 3 months since I am cooking most of my rocks to go barebottom. I have all the rocks up about 3" on eggcrate with a couple mag pumps underneath for flow. I actually get more compliments now than before, I think mostly because the corals and fish dominate the tank. So far my tank has been very stable and have not had to scrape the glass much. My mandarin needs to go on a diet.

[andycook]

What size rubble pieces are typically used? The rubble size used in most of the tanks in this thread seem to be on the small side, under 1".

My idea for my 180 is to use pieces 1"-6", like Mike O'Brian's tank except the pieces should be proportional to a 180g rather than a 10g.

[algaeguy]

Hi andycook:

I think that your idea for rubble sizing is right on. I think it is driven as much by aesthetics as it would be for maintenance. What I have found with my system is that the rock is rather loosely placed on the bottom, so there are really no areas that accumulate detritus. Essentially, the rubble bottom that I am using is a bare-bottom system, I suppose. Hence my thoughts about running lots of flow in the system.

The UGF ideas that have been proposed in this forum sound fantastic. I'd love to see what kinds of things reefers are doing along those lines!

I found that it is quite easy to get realtively inexpensive slab rock and "bust it up" with a soft mallet to meet your own size requirements.

Last night, I was at the house of a local reefer/friend who has a rubble bottom similar to mine in his 350gal, and the tank/effect is stunning. He has all kinds of Zooanthids, Blastomussa, Faviids, etc throughout his rubble bottom, and the sheer diversity of life is amazing!

He has a very large population of foraging fishes, like Mandarins, blennies, gobies, Centropyge Angels, Leopard Wrasses, etc. All are thriving, and the colors are spectacular.

Again, I think that the "rubble bottom" idea is really a neat concept. Hardly rocket science, but just another way to run a cool reef tank!

If I had to do it all over again, I think that I would have ran my system "fishless" for a few months, while innoculating the system with cultures of amphipods from a source like IPSF, and really letting the system acheive maximum biological diversity before stocking with fish and corals...Would take a lot of patience- but how cool would that be?

Scott