very slight algae

[nismostate]

You have an swg.. if it didn't work for you at 7 FC, why not keep FC at the higher level like 10? at cya of 70,

have you tried raising fc?
I thought that there is a disclaimer saying that the charts are just a rule of thumb and it may be different from pool to pool. try keeping it at a higher fc level. it couldn't hurt.. it may be possible that your cya reading is off? thought i read somewhere that it can be +-15ppm. so maybe you have a higher cya reading than you think and reason why algae keeps popping up?
just throwing some suggestions out. i'll let the pros correct me if i'm wrong.

 

[linen]

Lots of questions for you:

When (time of day) are you normally testing for FC (when not shocking)?
When are you running the swg and how long does it run (or when does it start and stop)?
Are you having to also add any form of chlorine?
What is the square bucket in your equipment pictures?
What is you latest cya measurement?
Did you go to mustard shock level for 24 hours after you passed the three criteria the last time?
Have you been using the solar cover?
Is the hot tub typically in your circulation loop?
Are you able to get a circular pattern of flow in the pool?
Is your pump a 1speed or 2speed?

 

[Lisaheidinger]

I test in the morning
My pump fins from 9 am til 7pm st at 60% to keep 7 ppm of FC
Not adding any bleach except when shocking
Just an empty bucket to hold stuff
CYA 70
Yes mustard shock
No solar cover at all warm enough not to need it
We don't use it as a hot tub, it is alway circulating and waterfall is running when pump is on
Things get stuck in the alcove to right of waterfall ( I think the waterfall stops them)
One speed pump

Thanks
Lisa

 

[Lisaheidinger]

I pool passed all three of the required Standards for the OCLT test this morning.....again. I'm going to slowly lower FC to 10 this time.