Random things:
12V power supply for four Current LED+ lights instead of using four bricks -- more efficient and likely will last longer as it has a fan if it gets too warm. This was an old PC power supply that would otherwise be thrown away. It also provides +5 for a Raspberri Pi computer to control the lighting.
Put a Tee in one canister on each large tank, with ball valves, and a regular garden hose attachment on one end. Now I can pump water out in about 20 minutes (for a 220G taking out 80G) instead of siphoning for maybe an hour, plus much easier. In two others (45G and 30G) I just stick the side run of hose out a window and pump onto the grass.
For spot treating algae, etc. in tanks without disturbing the water (filter off of course) - turkey marinating syringe (about $4, maybe less at a flea market) and a bit of stiff tubing, used a small bit of flexible water tube (like for an RODI) to join the two and then covered that with hot glue (slowly so as not to melt it). now I have a 3' long syringe I can reach anywhere in my big tank (or small also of course) without disturbing the water with my hands, and holds a good big dose.
Can also be used for removing waste in spots, e.g. in a fry tank you don't want to siphon for fear of getting, well, fry.
I started with these intakes in a big tank, but later put them even in a small 30G as I really like them. They are standard PVC parts leading to a screw thread, then I buy a pond prefilter from Home Depot (a bit pricy at $10). It keeps big stuff and stock out of the filter, but is porous enough it does not load up quickly. Easy to clean, and you get a spare pre-filter media.
I now put one cross-ways (i.e. on a 45) near the bottom of each tank so when I use the Tee above to pump the tank down, I can pump it WAY down.
Big tank largely hidden spray bars. I have three smallish filters (2xSunSun 404B and one Fluval 306) on a 220G tank instead of something huge, and I take each and feed it out via black-painted PVC along the edge, under the rim, and across at each support. While not exactly invisible, they are not readily seen when looking into the tank, yet they keep good aeration across the whole top (this is viewed from below toward the top of the tank when it was first being planted, no stock as of this shot).