Does a cover increase algae?

[davedive]

I have an automatic pool cover and before this heat wave it was closed up for a good part of the day. As it warmed up suddenly I'm struggling with my pool chemistry- I can't keep the FC at a good level- pretty sure I have algae and wondering if keeping it covered allows it to grow more? This morning I tested and found no chlorine- even though I've been dumping in gallons of 7.5% bleach! I'm losing the battle! Here are the numbers:
FC- .1
pH- 7.0
TA- 100
CH- 420
CYA- 70
salt- 3500
It might be time to SLAM?
So is it possible leaving the pool covered can promote algae growth?
Thanks!

 

[Newdude]

Welp. Yes and no. When covered there's much less UV loss. So it's most likely that you didn't account for the full UV loss when open. You effectively have 2 pools and need to account for which one is being used each day.

If you see any algae of any kind, cloudy water, on the walls, dead algae poofing on the floor when brushing, etc, then it's full SLAM Process ahead.