I have just tonight absolutely confirmed what I've been suspecting over the past two seasons. The chemical system I've been using, for whatever reason, is working well enough to keep the water (most of the time anyway) quite clear. As a result, a false assumption is easy to make that there is no white water mold accumulation. This is not the case. With the water as clear as it is and the low sun on it tonight, I used the brush and notice that a good deal of WWM comes off the walls and floats in the water. Especially discouraging - after adding a gallon of oxidizer today and 2 pints of biguanide - a container of "Ahhsome" yesterday, etc. there were large clumps of what I presume to be WWM growing along the wall of the deep end. Most of the problems occur in the deep end - always have. If everything I'm using is not just keeping the water clean but also (presumably) killing these organisms, I should not be seeing this accumulation. So the mold is there, all the time, but unless brushed and/or readily visible ala these larger growth clusters that seem to materialize within 24 hours (they were NOT there last night), it's easy to think that I've got things under control. The next logical leap is that the stuff is in the water all the time as well and so I'm swimming in it despite, again, the water looking really good.

This is truly depressing, since I do not know what else to use to fight this problem. I shudder to think what the lines look like. I guess I should be brushing more often but that = even more problems with the filter. Pressure is now up to 17, which is an increase of nearly 5 lbs. in 2 days. I don't know how I'm going to get through this season with 3 more months to go. Might as well pitch a tent next to the filter tank I suppose. Right now I'm feeling pretty down about the whole thing.
Are there any alternatives besides chlorine and baquacil? Just wondering....