dual filters usually an eheim canister at one end of the tank and an aquaclear at the other and yep dual heater 1 under either the outflow or in inflow-Anne
2 random whisper filters on the 20 gallon...1 heater
Double filters on the 40 for softshell turtle (AC 70 and a whisper internal for 40 gal) 1 heater
2 AC110 and a fluval 405 on the 120, a 550 powerhead, 2 airwalls and a Stealth 250
1 penguin 350 and 1 AC110 on the 55, a 550 powerhead, two airwalls, and 1 heater
3 FX5s on the Aquaripond, 1 with the sponges and all ceramic bio in every basket going into a Waterfall spillway filter with sponges, ceramic bio rings, and pot scrubbies, 1 with just the sponges and scrubbies in each basket going directly into the tank, and one with the sponges and ceramic bio and zeo-carb going directly into the tank. Also a submersible pond filter with a bell fountain attached rated at I think 700gph. And several random heaters in the waterfall spillway to heat the aquaripond. Oh, and a 25W Gamma UV sterilizer on a 900 powerhead. Works perfectly!
In my 600l ive got 1 fx5 1 xp3 and 2 380l sponge filters and 3 300w heaters.
In my 450l ive got 1 fx5 and 2 380l sponge filters and 2 300w heaters.
In my 200l ive got 1 small fluval not sure what kind and 1 380l sponge filter and 1 300w heater
gotta a lotta doubles with me too
in my 180 i have 2 overhead trickle filters so to pumps for those trickle as well.
in one of my 55G there are 3 internal canister filters
and in the other 55G there are 2.
and finally in my upcoming 240 G i will have 2 300W heaters and 2 Pumps to pump water back into the main tank from the sump