I think my yabbies and shrimp survive their moult because of my hard bore water........calcium and magnesium, and I add shell grit. I'll try and get some photos, cam. I always feel unworthy since I only have one tank and its an old stainless steel framed "Perfecto" which I'm cleaning up.
I've got 80 MacCullochella peelii peelii in a 2300L poly tank, 100 glass shrimp in 10 x 20L plastic tubs, one 6" female yabby "Princess" in her palace and lots of small yabbies in 20L tubs which I need to sex and grade, 60 Pacific Blue Eyes in halved 200L poly foodgrade barrels awaiting aquarium accommodation, and in the lined pond out the front are about 70 comets ranging in size from recent arrivals to some beautiful, longtailed 8" fish of all colour combinations. There're 6 or 8 bright rosy barbs about 60mm long which emerged the other day. I forgot I'd put them in there a couple of years ago.
They're tough, the goldies and the barbs. They live through freezing water in Winter and warm water in Summer with no mechanical filtration or aeration. All I do is top up the water level to compensate for evaporation and transpiration from the Phragmites australis, papyrus, lilies, duckweed and azolla.
I have no reason to do water changes in the big Murray Cod tank because a pond pump on a timer comes on for half an hour every 3 hours. It lifts water up from the tank and into a half barrel which has 400mm depth of recycled brick aggregate in it. The aggregate is between half and three-quarter inch diameter, and is porous like scoria and provides a good micro-environment for nitrosommona, nitrospira, etc bacteria. They're aerobic which is why its a half hour on, 3 hours off flood and drain cycle.
They transform Ammonia/ammonium (NH3/NH+4) to Nitrite (NO-2) and then to Nitrate (NO-3). I have vals and wisteria in the shrimp tubs ('cause they're on the same cycle) and spathaphylums in the aggregate barrel. These take up the Nitrates. Parameters are good, but the bioload is relatively low. The murray's are still under 8"long, so I'll have to have a secondary biofilter/plants system ready at all times.
I still haven't worked out how to use this solar HW panel to keep fish water temps up this Winter.
The 2 ton of water is easier to keep warm and manage than the little tubs. Because of this I'm going to (somehow) use the HW system to heat a thermal mass and maintain an ambient temp in the insulated fish shed.
So, there's plenty to do when you get here.