Tank build to replace T5 20L

[aparker]

It's inevitable.

 

Get an aquarium, build it out, start craving a bigger one. My 20L buildout thread (http://www.nano-reef.com/forums/index.php?showtopic=119022)

has been quiet recently because the tank's full and growing nicely. Here's the most recent FTS, over a month old:

 

I have handed out one frag of that Anthelia colony recently and I think a few more are in order. It has really taken off. A couple of the Montipora are getting close to needing a trim too. My Echinophyllia chalice coral has started to burn nearby SPS - a temporary plastic barrier is in place but that's not a long-term solution...

 

All of this adds up to - I need a bigger tank!

 

Fortunately it looks like I'm going to move in with the GF this spring, so there's room for something bigger. What I want to do is get the maximum possible increase in living space for my critters with the minmum possible bump in volume (more volume = bigger water changes = PITA). So the idea is a 48" tank, but long and low. I could go for a 33L, which is a straight stretch of the 20L - still only 13" tall. I'm worried that it would look a bit funny on a standard aquarium cabinet being only a foot tall, so I'm also considering going 40L - 16" tall. I would be interested to hear from those of you who have either of these size tanks.

 

Either way, the concept will be a split down the middle - high light/rapid water movement on one side, lower light/less flow on the other. I am hoping this will allow me to keep some corallimorphs and other lower-light corals that do not thrive in my current setup. So the high-light side would be lit by my present fixture - Aquatinics 5X24W T5, while the low-light side would have less light. If I go for the 33L (only 13" deep) I'm thinking even a 65W CF fixture would be enough (mushrooms, deeper water LPS, etc - no SPS here). If I do the 40L, I'm thinking maybe a 130W CF or a less-extreme T5 would be in order. But I don't want to over-do it; really want to be able to have some pretty Ricordea etc.

 

I would also design the CL circulation to return mostly on the high-light side, to provide lots of flow for my SPS corals. I am pretty committed to the no-sand approach. Not bare-bottom per se, but rather a floor of ping-pong-ball-sized coral rubble - big enough rocks to let snails move around to graze, and to let polyps spread to fraggable-sized rocks. All I get from the sand in my present tank is an algae garden....

 

I am thinking that to avoid detritus buildup I will place this rubble floor on top of a layer of eggcrate set 1/2 inch above the bottom of the tank, and blow water under this using a spraybar. I'm leaning towards the sump return doing this. If I go this route the 40L is almost inevitable, since I'll lose some interior height to the eggcrate.

 

One other thought is that I'd like to switch the CL off for chunks of time at night, to let the corals experience some calmer water motion (when I switch off for cleaning in the present tank, they extend tentacles more than I ever see with the CL on, so there's clearly some behavioral impact of 24/7 violent water motion). So I need a pump that will be durable over many on/off cycles. The cheap Quiet One pumps I've used so far are not confidence-inspiring this way. So I'm interested to know what you'd suggest. Iwaki perhaps? I'm thinking 800-1000 GPH is about right.

 

I'll add some drawings to this thread as they evolve....