That's great sounding tank- although perhaps unusual for a marine- most of the ones I see advertised are deep rather than wide. 3'x 5' gives you lots of options for bottom dwellers like catfish, loaches, dwarf snakeheads (if you like predatory thingies), etc. I take it you have an RO unit? If so I can't really advise on stocking other that to pick whatever you feel like.
Although I'd put a strong case for a nice biotope. Perhaps one that didn't involve a heater. ;) I think even the smaller gars are going to be too big- they're not particularly manoeverable. The heavy scales make them bad at turning corners. Beautiful fish though.
I took the vac end off the one I had and bought a Marina Siphon Start (the biorb one comes with a bulb at the end which is handy). I startt the siphon off, swirl the tube around above the sand and the grot that sits on the top gets sucked up. Any sand that gets sucked up gets sieved back into the tank with the new water, which means I can pull out MTS's and move them around to other tanks if I need to.
nathangoudie wrote: 4cm max adult size is suitable right?
As Fishlady says, it depends on the fish. If it isn't too active, and doesn't need company it should be OK. Of course the obvious choice (especially with your temperatures, and their habit of eating insect larvae etc) would be a Betta species. Unfortunately I expect the only one you'll be able to find reliably will be the standard Betta splendens How compatible they are with shrimp is very variable (species and individual fish), and anything 4cm+ is liekly to see shrimplets as lunch (depending on how good your shrimp are at reproduction this may not be a problem).
The other issue is pH. IIRC your water is pretty soft (which is good- and arguably more important than pH), but has a high pH, and I have no idea how suitable that will be for the fish. Its fairly similar to that of the Sulawesi lakes (and a similar temperature too). I have no idea what fish are found there, nor how easy they are to find.
What native livebearers do you have? There might be something small enough where you could keep a couple of males.
What are your water parameters? Does it have a substrate and plants or is it a bare tank? 90L is a good size for lots of different fish. The world is the mollusc of your choice (although Swan Mussels tend to fare poorly in aquaria, unless your water looks like pea soup.)
Given that he was a biggun, and therefore had a pretty big bioload I went to the shops yesterday to bulk up my WCMM shoal (I'm not sure what's going on with them- I bought some and lost almost all of them within a few weeks- all parameters are normal zero ammonia, zero nitrite, nitrate is normal, they just dropped dead- I really do need to get a QT tank), and I now have a new loach.
Within an hour of introducing it (I've not been able to check its gender properly) "Charm" (I'm sticking with naming them after quarks, and he/she was absolutely adorable in the shop) was happily snuffling around in the sand nibbling away at a pellet.
I'm still planning on getting a 500L upgrade, but I'll need a bigger house to do that in. I was tempted by some Puntius semifasciolatus, but they only had a couple of greenish ones, all the others were the much more yellowline-bred versions, so those will wait until I have a big enought tank to house everybody, and can find the wild-type ones (I suspect I'll have to check local auctions etc for those).
"Top", my biggest loach died today. He was a good 22cm TL, and about 2.5cm diameter, so probably 6-7cm around. Which is a good size for a weather loach, although from what I hear, by no means uncommon. He was however only threeish Which is not very old for a loach. They're supposed to get to about seven.
I'm not entirely sure what happened to him. He was doing the loachy dance quite a bit today and I think he may have concussed himself against the lighting unit on the tank. (I certainly heard a bit of a thump at one point, but he seemed happily swimming around immediately afterwards). But when the lights went on he was lying motionless at the bottom of the tank barely breathing. (He'd never played dead before, so I was immediately worried). I managed to get some water over his gills, and he was definitely still alive, but he slipped away fairly quickly.
I'm used to losing bitterlings and white clouds every so often, but shoaling fish don't have the personality of the "centrepiece" fish, and its different when one of them goes. Plus him and the other two loaches were my first fish.
Oh, no diagreement there, if you do go down the builder's sand route you'll need to do your research. If in doubt go with what you know, but if you need large quantities (the guy I'm thinkning of has 12+ tanks, most of which are 3' x 1' or so, then it becomes an attractive option.