Impossible to say what the problem is without being on site and even then it's difficult. If I take the words "brown" and "leaves" I'm going to be thinking tannins. AC can remove tannins but it's far from easy. Easier imo is to net or vacuum out the leaves and keep up with that and do water changes to remove the current tannins. But I've many cases where the owner said "brown" and it wasn't tannins but just a build up of dead organic suspended in the water. I would call it more of a grey, but brown would fit if you haven't seen a lot of ponds. It's a much more common issue, so if I were a betting man my money would be there. Easiest fix is the same for tannins. Remove organic matter (the source) and water changes to remove the suspended matter. There are filters for removing suspended matter, such as fabric filters and sand filters. How effective these are is dependent on the matter itself, so these are hit and miss. Flocculent can be used to removed suspended matter. Sellers make them sound easy, but the actual process is too complex for most people. Certainly not dump it in and walk way. I wouldn't be mad at your installer, the second filter is a crappy bio filter and even good bio filters don't fix tannins or suspended matter. I would call your "education" at the pond store indoctrination. Stuff in a bottle can have short term effects, but long term rarely does much good. Normally the cause has to be fixed. But all ponds are different. The lava rock in the skimmer is submerged media, and pretty poor media at that for such a small space imo. Again, its a bio filter, little effect on your issues and especially such a small amount. Lava rock in a Trickle Tower is 10-30 times better as a bio filter. So if you really wanted to add lava rock I suggest Googling "Trickle Tower". Super cheap and easy to make. Whether or not 60-100 lbs of lava rock will damage your filter is anyone's guess but I wouldn't care for the odds.

I just used the Feast and Watson Liming stain and varnish on my cypress pine boards....an absolute disaster! Doing a bit of google research I find sooooo many people who've had the same experience. I spoke to a couple of professional guys who said 'don't do it' (I still did). Sometimes it works out ok....but often it doesn't. Followed the instructions to the letter and still it went badly blotchy. Whenever the roller touched previously painted, it just grabbed at it. I've just had to sand the whole floor back again :(

@Jenny Medinger I hear you! I have agonized. Napa Dry Cork was actually one that I thought for sure I'd be installing. Def buy a box of whatever you are thinking of b/c the sample boards really don't give you enough of an idea. I spent $140 on a box and glad I did. The planks do look great -- it's a beautiful floor. But the light pieces were too grayish/yellowish for my house. I then decided to get a box of Napa Tannin since it looked warmer to me. But the dark planks were a little too dark for my house. So I decided that while I love both in other people's pics, I knew that having planks with that much variation were going to do it for me. I'm 99.95% sure I'm going with Coretec's Hayes Oak which is wider, with very low variation between planks. Again, even though boxes of unused LVP sucks to spend the $ on, it would suck worse to install something that you don't like once you see it in your home.

Hi lori l - Yes, we did decide on the Mannington Napa Dry Cork (not the APEX style). There is definitely color variation in the flooring, but I wouldn't say it's super drastic or overwhelming. We just recently had the flooring installed, so no real furniture in the room, but attached are some pictures of it in our space. Ultimately, we are happy with the flooring, and I agonized over the decision. Hope these help - Good luck!