If it helps any, I always use changed out water to water plants and it’s not necessary to worry about overdosing the plants with fertilizer because it’s so extremely diluted. The grunge from filter media does no harm and may do some good.
A dearly missed friend of mine who allowed me to house my fish at his place for a couple of years (long story I won’t bore you with) was convinced that fish tank water was the key to growing any plant and had me siphon my changed out water into 5 g jugs and he especially treasured the water in which I rinsed out the filter media. He shared the fish water with neighbours but kept the filthiest grunge laden jug of what he called ‘fish poo’ for his own plants.
Fish water will make most plants extremely happy and you can use it for every watering if you have enough changed out water to do that.
One notable exception to that advice is any carnivorous plant. A lot of them have to have nearly pure water in the form of rainfall or in potted culture, distilled water.
One can certainly see why they’re called ropefish.
I cleaned out the AC 70 on the
rimless tank when I noticed it was jetting water out the intake side. At least I caught it before it started pushing the media up out of the basket.
I have saved all the grunge and dirty tank water from the filter and the intake sponge cover in a large vase (which I intend to make into a
terrarium one day) but for now maybe it can be an infusorium instead.
I’m letting it all settle to see if any interesting wee critters happened to be living in it. I hope there are.