Pre SLAM Questions

[Nitzylplick]

So I have been reading pool school and various sticky threads on getting rid of alage/SLAMming and have ordered my TFT-100 kit. Getting everything prepared to get rid of the algae. Had some pool store shock and chlorine tabs but haven't been able to get rid of it. So I ran across this website and like the approach but have some questions. I have a plaster pool with a 48-DE filter. With all the backwashing, it seems like I will be going through a lot of DE, do I really need to add DE after each backwash or can the filter do some of the initial coarser filtering? I need 4 scoops every time I backwash and from reading, the filter is going to be full pretty quickly which is what I've experienced so far. Can you do a shorter backwash than the 2-3 minutes that are recommended? Or is it just not worth any shortcutting?

Can you swim while slamming or is it unsafe?

I have a basic pH/chlorine tester, what do you recommend I do while I wait for the test kit to be able to SLAM?

TIA!

I've read the following stickies:

http://www.troublefreepool.com/content/126-defeating-algae
http://www.troublefreepool.com/threads/3913-Turning-Your-Green-Swamp-Back-into-a-Sparkling-Oasis
http://www.troublefreepool.com/content/125-slam-shock-level-and-maintain-shockingl

 

[jblizzle]

Welcome to TFP!!!

Yes you absolutely must add DE after every backwash. When was the last time you took the filter apart and really cleaned everything? See:
Use and Care of DE Filters
DE Filter Cleaning Tutorial

We generally say it is safe to swim up to shock level, assuming you can clearly see the bottom. You are just slowing down the SLAM if you do.

Before you get the TF-100, just add some bleach every day. How much depends on your pool size.

Please add your pool details to your signature as described HERE as it will help us help you.

 

[Nitzylplick]

I'm a total pool newbie. I just moved in to this rental so I have never taken apart the DE filter (or any DE filter but did my 1st backwash 2 days ago since the pressure was up to 30 psi - following the backwash was down to 18 psi, now I'm back up to 28 psi so it's time again before the SLAM). In mid-June someone had turned the power off to the house and the pool was green. Landlord had the DE filter cleaned (handyman said he pulled it apart) and had shocked the pool but it probably wasn't enough. I didn't move-in until over a week later so the test from the pool store showed:

TC - 0.5
FC - 0.5
CC - 0.0
pH - 7.5
CYA - 0
TA - 100

Did some shock and pool tabs went to a different pool store and came up with these readings (they used a computerized test)

FC - 0.04
TC - 0.47
CC - 0.43
pH - 7.9
Hardness - 182
Alk - 89
CYA - 23

That was last week and I haven't been doing much since I ran out of chemicals, was reading this site and the bloom is starting up again.

Thanks for the newbie help!

 

[jblizzle]

For 12k gallons, I would add about 2/3 of a 121oz bottle of 8.25% bleach every day until you get the test kit and have real numbers.
Or a 1/2 gallon of 10% liquid chlorine.

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BTW, we recommend backwashing the filter when the pressure rises 20-25% over the clean pressure or the flow drops too much. If you start at 18psi, then you should backwash at 22-23psi ... this is going to happen very fast if you have active algae in the water.