Solved!

Easy Peasy Lemon Squeezy. All I had to do was release all the air from the filter unit by opening the valve on the pressure gauge on the top. Then undo all 8 of those clamps round the middle, lift the top off, lift out the two, huge, soaking wet, manky filters and the one small, but still manky filter. There's a drain underneath the filter pump, but I couldn't open it. I'm not sure it's ever been opened.


Instead I removed the tap on the front. Actually the whole white thing there came out. That drained the pump most of the way. The tap itself was totally bunged up with crap, so I disassembled it a little bit and cleaned it out. Then I hosed down the filters to clean them up a bit and reassembled the whole thing. I had to run the filter with the air valve open until water shot out, then I closed it and turned the tap on. Success! The water came pouring out. So I hooked the hose up.



Following my brothers sage advice I decided to continue dumping pool water in the lawn, so I ran the hose across to the back lawn and will dump it there until the lawn is saturated, then move the hose to the front if I have to.



See? Good stream. Nice flow. Very happy.



This was the pipe I thought might be for dumping water down. I filled it up with water from a bucket and it didn't go anywhere. Though a lot of crap floated to the top. I thought it might be clogged, so I poked a big stick down it. The stick wasn't big enough. It floated back up. So I poked my big stick with another littler stick and hit something that felt like dirt. My big stick floated back up, so I jammed it down with some force at which point it got stuck in whatever crap was down there. Damn. I'm not sure what I can do about it at this stage. I'm not particularly attached to the big stick and I can't see how it's going to be a problem, so I guess I'll leave it there for now. My back's killing me, those filters really were quite heavy, so I'm off to eat leftover pizza and maybe treat myself to a beer.