What is around my drain and how do I get rid of it?

[IronRon]

We moved into the house with a pool about 2 months ago. I found this site and we have had great luck with our pool... Until a couple days ago. The pool started to look cloudy during the day, so I added some bleach for good luck. The next morning it looked like this. I turned on the filter and brushed the pool. Turned on the sweeper for a bit longer hoping that would take care of it. During the day, the pool looked pretty good, but the next day it looked like this again. There is also a layer of this in the entry to the skimmers.

My latest numbers from last night are:
FC 7.5 added 45 oz bleach
CC 0
PH 7.7 added 18 oz muriatic acid
TA 90
CH 600
CYA 80

I know that CH and CYA are high, but will deal with that when we resurface the pool.

TA is low, but I did not want to add baking soda... Another powder to the pool until I figured this out.

Any thoughts? Is it DE getting through the filter?

 

[Smykowski]

Can you get in and touch/feel it? It looks like dead algae, and it would be slimy if that was it.

 

[IronRon]

I just felt the build up at the skimmer entry point and then opened the pump filter to feel it there. It felt more like very fine grit rather than something slimy. I am thinking it may be time to tear down the filter and check the fins. Anyone have any thoughts about that?

 

[Killer95Stang]

Check to make sure your spa and pool valves are in the correct position. I had one of the Valve actuators fail when I switched from spa mode back to pool mode and it dumped some of the DE powder back into the pool from the main drain. It looked exactly like your pool does, minus the dirty DE which looks like you need to backwash.

 

[IronRon]

Thanks for the info. I am convinced that it was DE. I had been playing with some of the valves that I had not moved before. Pressure is good on the filter but it has been a month since I backwashed. I will give that a shot and see what happens.

 

[IronRon]

I turned the skimmers off and the main drain on full power for the most suction. Then slowly and carefully swept towards the drain to get as much sucked in as possible. I didn't want to just stir it up and have it as a cloud in the whole pool. Then we had a day of fun in the pool. This morning it looked like this. Seems like it was just DE that had made its way into the pool when I was moving some of the valves around. Today I will backwash and reload the filter with fresh DE. Thanks for the advice.