Caribbean Biotope Seagrass Tank

[Michael Hoaster]

Ahh! Diver's Den! I looked, it was gone. Oh well.

I like your lighting ideas. I plan to use the lights I already have, which don't include any of the new LED variety. Those 'cannons' are cool though! For the seagrass, I have a 400 watt metal halide 6700K, with spiderlight reflector. For the other end, where the mangrove root is, I have a couple of 96 watt power compact fluorescents to play with. It shouldn't be too difficult to implement some strategically placed shadows for sponges, especially since the PCs don't put out much heat. No actinics on this tank. I'm going for bright, midday light, in shallow water.

Soon…

[Michael Hoaster]

Got the wall, root and planter done! Got about half the substrate in. Tanks filling! Takes about 4 days, I think.

[JLynn]

Yay! It looks great! I can't wait to see it wet.

[Michael Hoaster]

Thanks, JLynn. The DIY projects were a real struggle, but I'm finally past them. Coming up with my own solutions to the many problems along the way, was a step into the unknown. Having a community of enthusiastic followers has been invaluable!

[Michael Hoaster]

Here's a good look at the substrate.

Also, hidden in there is some silica sand and mulm-rich EcoComplete. I didn't rinse any of the substrates. I wanted to keep as much 'silt' as possible. And since the tank is filing so slowly it's not too cloudy.

[Michael Hoaster]

Here's the planter with all the substrate. The DSB is almost all sugar-sized oolite, with some silica and ecocomplete mixed in. There is a thin layer of medium and course grain substrate on top.

[Michael Hoaster]

I should talk a little more about the substrate. If you go back to the beginning of this thread, you'll see a lot of discussion about it. I was very focused on providing the best substrate conditions for the seagrass. Now I'm thinking more about the whole mini-ecosystem, or microcosm. You've got to start at the bottom of the food web, to support everything-including the grasses.

Different grain sizes support different levels of oxygen, which support different types of bacteria, etc. I want a variety of microfauna and flora, all the way up to zooplankton, for biodiversity in the (substrate) food web. I'm hoping the course stuff and shells will provide an in-tank refuge for benthic plankton, helping to maintain their numbers, even with predation.

Some might be surprised at my inclusion of silica sand. Remember, I hope to keep some sponges and sea squirts. They like silica.

Also, I'm hoping the aged ecocomplete will kind of act like compost, for the seagrasses. Speaking of which, I ended up ordering three different seagrasses; Shoal Grass, Manatee Grass and Turtle Grass. It will be interesting to see which will enjoy the conditions in my tank!

[karimwassef]

Very nice. I feel the agony of waiting for the RODI water to fill.

[greaps]

Keep us posted, looks awesome, what kind of inverts and fish are you planing again?

[Michael Hoaster]

Yes, the RO/DI wait is a long one. It looks like it's going to take longer than 4 days too. More like a week to 10 days, I'm guessing.

[Michael Hoaster]

Thanks, greaps. As for inverts, I ordered assorted pods with the seagrass and macro algae. Next will be snails. Cerith snails will be the most numerous, for their algae consumption, as well as their egg laying. Nassarius for leftover food cleanup. Conches for sand bed cleaning. No hermit crabs.

I also plan to add Caribbean anemonies, gorgonia, and sponges. For fish, I'll have royal grammas, cherub angels, some kind of caribbean chromis, chalk bass, a blenny, a blue tang, and possibly silversides and lookdowns. There a few other caribbean fish choices I'm still considering, but that's most of them.

[sam.basye]

How did you end up securing the entire wall? The clear diffuser covered by sand to prohibit float - what about the back of the wall?

[Michael Hoaster]

Good question, sam.basye. First of all, the pieces fit pretty tightly, second, the bottom two pieces are zip-tied to the bottom piece and wedged under the overflow. To get everything snug to the wall, I used a little epoxy putty in a few places. So it's semi-permanent. I'm pretty sure I can pull them out if necessary, but I'm not going to sweat a few small gaps here and there. So I don't expect to fool with it, now that the project-from-hell is done!

[MorganAtlanta]

Originally Posted by Michael Hoaster

I ended up ordering three different seagrasses; Shoal Grass, Manatee Grass and Turtle Grass. It will be interesting to see which will enjoy the conditions in my tank!

Where did you end up ordering your grasses from?

[Michael Hoaster]

The shoal and manatee grass are from Florida Pets. The turtle grass is from Live Aquaria, diver's den. I got six of each grass. I was hoping to get more manatee grass, but the larger quantity was sold out, so I decided to do all 3 and see what happens. Since the shoal and manatee grass are pioneering species, I expect them to do best at first. As the sandbed matures, I hope the turtle grass takes off. We'll see!

[karimwassef]

Is the foam floating?

[Michael Hoaster]

All foam is present and correct, with eight inches of water so far. Hopefully, it will stay that way when the tank fills up. If it doesn't, please shoot me!

[karimwassef]

Just means you need some rock foamed to the bottom if it does

[Michael Hoaster]

I guess that would work, karimwassef, but I still may prefer the bullet!

On a completely different track, I had another crazy idea. I've been considering whether to dust off the 'ol nitrate factory', aka wet-dry trickle filter. I've also been thinking about carbon dosing via a bio-pellet reactor. But I'm not crazy about adding complexity to my system.

So I was thinking of combining the two, by putting bio pellets in my trickle tower. I realize the pellets are made for a fluidized reactor, but I bet they'd also work, albeit less efficiently, in the tower. I wouldn't have to add any plumbing or pumps, or any other complexity. It's a low-tech solution, which is my favorite kind.

On the other hand, does it accomplish what I want it to? I don't know. What I want is two things; increased bacteria production and an additional carbon source for the seagrasses. I'm pretty sure I'd get the first one, but not so much on the second. This is where direct dosing differs from using a bio pellet reactor. Direct dosing happens in the aquarium, so the carbon would be available to the bacteria and everything else in the tank. Whereas the 'magic' happens in the reactor, with a reactor. So, is carbon bio-available to my seagrass in the tank, or is it confined to the reactor? And does my trickle tower idea help or hurt the situation?

Any carbon-dosers out there care to weigh in?

[Whiterabbitrage]

Looks great! Can't wait to see it planted.

[karimwassef]

You can just call me Karim.

So I don't understand. Why would you need a reactor or wet dry?

You have the ultimate filter in a sea garden. It should act like a natural macroalgae scrubber?

Adding pods, glass shrimp and crabs should add the planktonic stage, and feeding your fish should drive the nitrogen and phosphate cycles?

I don't know much about biotopes so please excuse me if it's a dumb question

[Dr.Brain Coral]

Nice, Looks good

[Michael Hoaster]

I'm glad you asked, Karim. And you're right about my tank being a plant based filter itself.

Early in this thread we discussed C-N-P (carbon-nitrogen-phosphorus) ratios of seagrasses, and which of these might be 'limiting' their growth. It was suggested that the grasses may be carbon-limited, and that by adding bio available carbon, the grasses would benefit. It is also hoped that additional bacteria production would feed filter feeders like sponges.

The idea of using a wet dry, instead of a bio pellet reactor, with bio pellets in place of bio balls, is just me 'thinking outside the box'. I want to combine the simplicity of a trickle filter with the benefits of bio pellets. But since the pellets are the carbon source, and are confined to the filter, I don't think I'll get much carbon from them. So, it's probably not a viable idea. Carbon dosing right in the tank with vinegar or vodka, etc. would likely be more effective. I just want to avoid having to 'dose'. I think this idea would provide additional bacteria, which would benefit filter feeders.

Bottom line, I was just throwing ideas out there that might help my grasses get off to a good start, not to provide additional filtration.

[karimwassef]

Ok. If you want bacteria, then carbon dose. It's the simplest approach, even if you use an analog drip line (IV like).

In my tank, I'm considering a phytoplankton aquaculture reactor to kick my cycle into gear to feed the pods in my macro scrubber to feed my glass shrimps and crabs to feed my fish and coral.

I started with adding pre made phytoplankton and everything that can reproduce in my 2 month old tank is doing so. My polyp extension at night is ridiculous and my hair algae (yes...) is hopping full of pods (like fleas on a dog).

I think in your case, you map out your food cycle and then feed the base.

[JLynn]

"As the concept of using biopellets in home aquariums has become better understood and more refined, the need for aggressive mixing of the source of solid carbon has become clear. But simply slapping a larger pump on the biopellet reactor decreases the dwell time of the aquarium water inside the reactor, hampering the bacteria colonies from properly doing their job of biologically processing the nutrients therein." - Reef Builders

Based on that (^) I would say that a trickle filter would not produce nearly as many bacteria because of the lack of "aggressive mixing" and the reduced dwell time. IMO, not really worth it to put them in the trickle filter.

I am pretty sure that in the article I mentioned a while back (while we were talking about sponge food and plankton) from Coral Science, they said that in the shrimp industry, they floated the biodegradable plastic pellets (which I think are just biopellets by any other name) directly in the tanks. I don't know if doing that would get you more bacteria, but I suppose it is possible that bacteria get shredded by the pump on the reactor. Just a thought.