New brackish setup, feasability study ;)

[maniki]

Hi all,

I haven't had fish for a while, but i'm in the process of getting new tanks and so on. I'm going to be trying something a little complicated so i'd like to hear what some more experienced people think.

I really like the idea of an aquarium as an enclosed ecosystem so i'm aiming for something with a fairly low bioload, and as far as possible self sustaining.

Larger tanks are said to give better stability in this regard - however there's nowhere in my apartment to put a monster tank so i'm getting two smaller tanks and linking them up (~60 litres (17gallons) each). Still not huge, but I have the space to upgrade one of them if it works out.

Would this be best done via an external filter - intake from one tank, output to the other, with the return via a connecting tube - or should I put the filter on one tank and have a separate pump to connect the two?

Brackish water limits the plants that I can use, but I am still going to try and plant out both tanks (i will be aiming for the very low end of brackish 1.003-1.005). The only fish I am planning on at this point are some bumble bee gobies in one of the tanks.

The other tank will get shrimp, brine shrimp (for the BBGs) and eventually a crab or two (the placement of the tanks means that this one will naturally be somewhat elevated, so I should be able to have some land space at the top while maintaining a constant water level between the two tanks).

I was thinking malaysian livebearers and nerites as well, if they will do ok with the salt? I've seen conflicting comments re: snails in brackish water.

Any comments would be very appreciated, I haven't had a tank in 4 years or so, and never a brackish tank, so i'm not sure how easy this will be to set up.

Cheers,

Josh

 

[Sploke]

A self-sustaining tank is very diffucult to accomplish, even moreso with a brackish tank due to the great variation of organisms that can live in brackish water. I'll try to hit on each one of your points here...

Linking two tanks via a canister filter and a water bridge/siphon loop can work fine, I've done it before. Very possible as long as you plan it out carefully.

There are a fair number of plants that do fine in low-end brackish. Check out this link for a listing: http://www.plantgeek.net/plantguide_list.php?category=8

Bumblebee gobies are a good choice for that size tank and salinity.

1.005 SG is nowhere near enough salinity for brine shrimp to grow - think closer to 1.026 (closer to full seawater). They will survive for a few hours if you add them in, but you won't be able to get them breeding in that.

Fiddler crabs or red-clawed crabs could work in a tank with some land area.

The only nerite species I have experience with are the olive nerites, and I have a group living happily in a brackish tank at 1.012. They are very adaptable.

 

[maniki]

**** you're right about the brine shrimp. I misread a faq where it talks about rehydrating the eggs in 1.005. I'll have to try out some other species, though given the lack of labeling in the LFS this is going to be rather trial and error. I really like the look of the gobies, but culturing live food for them will be a bit of a pain.

When you were using a canister filter / water siphon system, did you get a huge difference in levels between the tanks? what size siphon tube did you use?

Cheers,

Josh

 

[Sploke]

I was actually using a 3" pipe connected below the water level with bulkheads - I wanted something large enough that guppies and goldfish could swim back and forth. If you were using a siphon bridge, I think 1.25" would be plenty to keep up with most canister filters.

FWIW, my bbgs eat frozen thawed mysis, bloodworms, brine shrimp....doens't have to be live.