Outdoors Tank Questions

[GotCrabs]

OK, so seeing @Baccus with his native tank has made me want to do another native tank again, damn you @Baccus, damn you!

So just wanting to know a few things, I already have a 20 odd litre tank sitting outside with just White Cloud Minnows and Glosso in there, but the White Clouds handle the cold well down here in country SA, it's unfiltered, unheated sitting in complete shade with just the natural light and it's going well, now if I wanted to add a little school of Threadfin Rainbows for mozzie control and some native Shrimp like Darwin Algae and Chameleon, I'd need a heater wouldn't I, especially for Winter but also for Summer when we some times get a cold snap here and there.

Would pool sand be OK as a substrate? Tank planted with plenty of flora, Glosso, Rotala, Vallis, Water Sprite, Hairgrass, Limnophila.

 

[Baccus]

Who Little ole Me? Guilty of making others crave a few natives......Bahwwwhhaaaaaaa

A heater certainly would be a must for the tropical guys, in winter I can struggle with cold in my tanks and have the opposite problem with heat in summer, hence the open topped tanks with almost all HOB filters for good water movement and surface rippling.

Lots of people use pool sand in their tanks, in mine I just used play sand that you get from Bunnings and the like for kids sand pits. It will need a good wash before using it, but I find give it a rinse till the water runs clear (making sure you really agitate the sand all the way to the bottom of the container your using to hold it while you rinse) and then add the sand to the tank and have some fine filter fibre in the filter. You could also use a sieve to rinse smaller amounts of sand, just don't take the kitchen sieve unless you plan on replacing it quickly. The filter will help remove anymore of the last really fine silt that is almost impossible to wash out without losing half the sand. With the sand because it can compact and cause anaerobic bacteria to flourish I also have just plain washed river gravel. I find having the gravel mixed with the sand really helps the planted plants spread their roots right through the substrate. Burrowing snails can also help with preventing compacting of the sand, but the main easy to obtain MTS I find become a problem in their own right.

A 20L tank might hold a small collection of threadfin rainbows comfortably but they are quick movers and can be pretty active, I would tend to place them in the Danio sized type of tank with some length to the tank. My threadfins go hell for leather from one end of the 4ft to the other and end up having to come to a screeching holt or  U-turn and whip down to the other end of the tank. Pacific Blue Eyes are surprisingly large too and always active. For a 20L tank with some small native fish I would honestly suggest something like spotted blue eye, blue-black blue eye (or neon blue eye) , or if you can find them Honey Blue eyes. I have heard of Honey Blue eyes living year round in a small pond on a patio in Sydney.

I would get the shrimp established and breeding first then add the fish, even though my spotted blue eyes don't seem to predate on the shrimp in huge numbers I am sure they eat a few shrimplets.

Alternatively instead of adding fish you could put a fly screen cover over the tank to keep out mozzies and other worst pests like dragonfly larva. I once had a whole heap of dragonfly or nymphs almost clean out an entire tank of black cherry shrimp before I found the culprits. Shrimp I have found at times too will eat the odd mosquito wriggler but don't seem to actively hunt them like fish will.

Just to give you an idea of just how many blue eyes there are out there check out all these
Pseudomugil connieae

Pseudomugil cyanodorsalis

Pseudomugil furcatus

Pseudomugil gertrudae

Pseudomugil inconspicuus

Pseudomugil ivantsoffi

Pseudomugil majusculus

Pseudomugil mellis

Pseudomugil novaeguineae

Pseudomugil paludicola

Pseudomugil paskai

Pseudomugil pellucidus

Pseudomugil reticulatus

Pseudomugil signifer

Pseudomugil tenellus