My list is too long right now and does not seem to quit growing.
For marine tanks running right now:
M1. 75g holding tank/QT about to be plumbed to 75g sump that is being used while I make progress on my living room build.
M2. 40g Breeder QT that needs to be sanitized and restarted after a wipe-out, probably due to bacteria toxins.
M3. 40g Breeder to hold live rock from my FOWLR shut-down/transfer.
M4-7. 4X 5-1/2g QT tanks for separating small groups of small fish.
M8. 20g Tall tank with cycling biomedia including bioballs and sponge filters.
...then freshwater:
F1. 40g B for community including cherry barbs, harlequin rasboras, zebra danios, corydoras catfish, otocinclus catfish, and 2 Chinese algae eaters.
F2. 40g B with black mollies, cardinal tetras, Siamese algae eaters, black khuli loaches, and a Chinese algae eater.
F3. 40g B with mixed rainbowfish, Siamese algae eaters, and black khuli loaches.
F4. 40g B with weather loaches, white cloud mountain minnows, and hillstream loaches.
F5. 20g Tall with exploding population of Endler's live-bearers that was originally started to raise out tadpoles.
All the freshwater tanks are running well with little maintenance except for algae issues in the Endler's tank and dirty/cloudy water conditions in F4 due to the weather loaches...
Empty tanks include:
E1. 2x 125g for my reef display and sump going into my living room.
E2. 2x 5-1/2g for additional QT's if needed/desired.
E3. 30g Breeder for additional QT if needed/desired.
E4. 2x 55g, no specific plans.
E5. 20g Long, no specific plans, needs re-siliconed after mice chewed of the interior seam beads.
E6. 29g Tall for a possible bedroom freshwater tank, though I've got too much going already for now.
E7. 90g, no specific plans.
E8. 2x 15g, no specific plans.
E9. 8x 10g, no specific plans, possible QT/breeder tanks for marine or fresh water.
I've found too many good deals on tanks and have too many endless dreams...
I have a 12ftx12ft room in my basement that is now dedicated as my fish room.