Questions before first SLAM

stillios

Member
Apr 22, 2021
19
Columbus, OH
I had the FC at the SLAM level of 20 after dark last night and it was 18 this morning, so I am still SLAM-ing today. The pool is blue but still not clear. I can see the main drains in the bottom of the deep end today, which is an improvement over yesterday. Yesterday evening I followed the TFP process for adding DE to a sand filter, and I think that is helping move things along.

Question about backwashing with added DE: the PSI was 14 before adding DE and raising it to 15. Last night it went up to 19 and we backwashed before going to bed, since that was about a 27% increase from 15. Overnight it climbed back up to 19. Is the 25% increase in PSI still the recommended point to backwash when using DE in a sand filter? If so, should it be 25% from before DE was added (14) or after (15)?

Question about swimming: Since we can see the bottom and the FC isn't exceeding the target SLAM level, how do I know if it is okay to swim if I can't reliably measure the pH? I guess my question is what exactly is the definition of "safe to swim"? It has been a week since we started several days of draining to reduce CYA, so the kids are getting antsy!
 
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mknauss

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If so, should it be 25% from before DE was added (14) or after (15)?
From base clean pressure. 14
how do I know if it is okay to swim if I can't reliably measure the pH?
As long as you have not added any acid or acidic products, your pH will not be lower than 7.2 and thus safe to swim in.
 
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stillios

Member
Apr 22, 2021
19
Columbus, OH
Still doing the SLAM. The pool seemed very clear on Saturday but there was some algae on the bottom on Sunday morning. The pool seemed very clear yesterday too, but, again, there was a bit of gunk on the floor this morning. FC went from 20 to 17 overnight, so stuff is still dying in there. Just want to verify, this IS algae on the bottom, correct?
IMG_3422.jpg

This how the pool looked in general this morning before using the automatic cleaner:

IMG_3425.jpeg
IMG_3426.jpeg
 

mknauss

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Pentair Intellichlor IC-40
That is really bright green for a pool with SLAM level FC.

Stay at it.
 

cowboycasey

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Almost too bright... is that slimy or does it fall apart when touched... looks almost like a green highlighter pen leaked right there...

Do the spots like that go away when brushed?
 

stillios

Member
Apr 22, 2021
19
Columbus, OH
That is really bright green for a pool with SLAM level FC.

Stay at it.
Yeah, that's what's concerning me. I've been keeping the FC up and checking to make sure the FC really is up after adding more bleach. It has looked clear all day for two days and both following mornings I woke up to this. Where is this coming from?! The kids have been swimming the last two days, but they aren't doing anything extra gross and FC is up before I go to bed. Good thing I ordered a refill for my FC test because I'm using a lot of it!
 

stillios

Member
Apr 22, 2021
19
Columbus, OH
Almost too bright... is that slimy or does it fall apart when touched... looks almost like a green highlighter pen leaked right there...

Do the spots like that go away when brushed?
I haven't touched it with my hands, but it turns into a cloud immediately when brushed and just disappears as soon as the automatic cleaner drives over it. It looks more brown-ish (like sand, but it isn't sand) in person. Or kind of like the color of infant diarrhea, if that means anything to you. :)
 

cowboycasey

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That is algae :)

keep at it....
 

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Newdude

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Jun 16, 2019
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NY
Or kind of like the color of infant diarrhea, if that means anything to you.
Goodness !!! I had totally forgotten for a while there. THANKS for that. :ROFLMAO: Some things are better left forgotten.

when was the last time you cleaned you filter ? Any change it’s residual and being reintroduced?
 
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stillios

Member
Apr 22, 2021
19
Columbus, OH
It is bright green in your picture.
Yeah, I definitely agree with that! I just doesn't look bright green when you are walking around looking down into the pool. My husband thought it was sand. That's why I took a picture, zoomed in, and asked. Can't wait to get rid of this stuff! Thanks for all of your help!
 

stillios

Member
Apr 22, 2021
19
Columbus, OH
Goodness !!! I had totally forgotten for a while there. THANKS for that. :ROFLMAO: Some things are better left forgotten.

when was the last time you cleaned you filter ? Any change it’s residual and being reintroduced?
Sorry for the traumatic flashback! :)

We moved into the house less than a month ago and haven't cleaned the filter ourselves. I have no idea when it was last cleaned. It sounds like we should figure out how to clean it today.

So if the filter really needs to be cleaned, that can cause algae to flow through the filter and back into the pool? We had this on the floor occasionally when the pool company was taking care of it too. They just told us to use the automatic cleaner.
 
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Newdude

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So if the filter really needs to be cleaned, that can cause algae to flow through the filter and back into the pool? We had this on the floor occasionally when the pool company was taking care of it too
It’s probably pretty nasty in there. You cleared the water but are spewing filter algea back into the pool. Which is probably why what is there is so alive and not the normal dead kind we’d expect with such clear water.
 

Newdude

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Jun 16, 2019
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NY
Ok, great start !! Search for ‘deep clean sand filter’. If it’s really nasty, the quick backwash won’t cut it. See this thread with a DE filter. It’s different than yours but same principle I’m going after. :)

 

stillios

Member
Apr 22, 2021
19
Columbus, OH
Ok, great start !! Search for ‘deep clean sand filter’. If it’s really nasty, the quick backwash won’t cut it. See this thread with a DE filter. It’s different than yours but same principle I’m going after. :)

After reading a few threads on this site, I took a few pictures of the setup for advice on whether or not we have to cut the pipes to get the top off. Do these need to be cut or do they come apart at the bendy pieces?

IMG_3431.jpeg

IMG_3429.jpeg
 

Newdude

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They do not come off at the bendy pieces. (Elbows……. But my vote is we *now* officially rename them).

I believe if you undo the bolt/screw where the black MPV base meets the Tan filter (below and left of sight glass in pic 1) , it would have enough play to slide the filter out and leave the rest suspended above. Hang tight for more opinions on that.
 

stillios

Member
Apr 22, 2021
19
Columbus, OH
Two more pictures: Could we take the pipe apart on the intake line at that joint about a foot up from the pump? And does the return line come apart from the heater?

IMG_3432.jpeg
IMG_3433.jpeg
 

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