Help with pump and lava rock as bio-filter for pond
Well I'm finally get around to getting my pond put in (it's a preformed plastic liner type). I'm at the point of adding my pump and filter. I bought a used Little Giant stream and waterfall pump from a guy for a good price. He was using lava rock for his filter. The lava rock is just sitting in a bucket and it has some sponge that sits on the top. I asked him how the pump fit into the whole scenario and I think he said he removed the lava rock then put the pump in and then filled it back up with the lava rock (I think). I should've written it down because now after a couple months I can't quite remember what the guy told me.
Does this sound right? I'm assuming the water gets drawn down through the lava rock then into the pump then back out again. I just realized I forgot to ask him how often he clean the pump. I can't imagine lifting that bucket out full of water and rocks. Any suggestions on this as well?
I tried googling it and found a couple posts but the buckets in those posts had pipes running through them which is not the same setup as this. Does someone have a similar setup to mine or has seen this setup and can tell me what to do? I have posted a couple pics of the bucket full of lava rock and the pump.
I was thinking of switching the lava rock to bio-balls because I head the performance and cleaning is better and of course it's lighter. Regardless of whether I use the rock or bio-balls I'm assuming the positioning of the pump would be the same.
Geez, I can't believe I'm stuck on this part of the process! LOL!
Thanks for any help with this!