What a morning.
It was time to do something with the 180 litre.
I finished adding WS3 at high dose on 26 June, and started eSHa Exit on 28 June. I emptied the bottle of Exit on 4 July. The first batch of carbon went in on 5 July, and it was changed on 7 July.
All that's in the tank at the moment is lots of wood with various plants attached and no substrate. The filters are an Eheim biopower 240 and a biopower 160 with the pump from an Eheim aquaball 2212. The aquaball is the first I had and as I'm not using that filter at the moment I used its pump when I got the smaller biopower.
Everything went well at first. I took all the wood out and put it in my fishkeeping dustbin (it is a dustbin, it's 60 litres and very useful for putting wet things in when I need to take them out of the tank). Then removed 64 litres water, hoovering the mess off the bottom of the tank, and replaced it with nice clean water. I threw away the carbon from the small filter I keep just for that, and replaced it with Polyfilter to remove the last of the meds. I cleaned the two biopowers, both media and impellers and wells. Then I turned the filters and heater back on. The smaller biopower didn't work.
A lot of messing about proved that the pump worked without the cover on but wouldn't work with the cover on. OK, I though, just swap the pump for the one that came with the filter and play with the old one in a bucket of water later.
That's not as easy as it sounds.
The 180 litre has glass bracer bars attached to all four sides right at the top of the tank. The front one overlaps the side bars but the back one doesn't; there is a square that is not covered at each rear corner. This is for the heater wire and external filter tubes to get into the tank. There are two holes in the back of the lid for these to go through. But my filters are internals, the wires from them need to go through these squares and lid cut outs. The filters themselves won't fit through so I have to push the plugs upwards through the squares and out through the lid holes. And I'd just filled the tank.
So I then had to remove 20 litres of water to drop the water level enough to get the plugs through, one in and one out.
I finally finished two after two and a half hours. The tank is filled again and all three filters are running. At least I don't have any fish in there or they'd have been cowering in a corner while I was trying to get the filter pump to work.