What is this and what do I do?!

[HeatherH]

Hello! I am finally hopping on TFP because of all the issues that began last year and continued into this season. Sorry for the extremely long post.

Here is the problem that I CANNOT seem to fix no matter what I do. Last year mid summer, the pool got a little hazy and had a green tint. I shocked and scrubbed. A bunch of dead algae was at the bottom the next day. It’s like dark sand except it turns into a cloud when you push it around. While the water cleared up, the dead algae at the bottom has not stopped showing up since. I have triple shocked for days in a row, scrubbed, algecided, vacuumed to waste, everything I can think of but the stuff just won’t go away. Leslie’s told me mustard algae and gave me copper Algecide. I finally seemed to get it under control for about two weeks last year, but then it started up again.

I was REALLY REALLY hoping that the winter would put an end to it and it wouldn't be an issue this year, but no. Same thing. I’m ready to give up and just join the community pool at this point.

Because I am still fairly new, I never rinsed the filter after backwashing. I honestly had no idea that was a thing I was supposed to do. I put in filter balls instead of sand two years ago. I’m wondering if this stuff is just chilling in the filter balls and I can’t get rid of it. Can all of this just be because of not rinsing? I rinsed really well last week, but when I put it back to filter, a nasty green cloud came out of the returns. I tried rinsing until that stuff stopped coming out, but I would run out of water because it didn’t seem to ever stop.

I intend to shut down the pump on Friday, take out the filter balls, and put sand back in, but will I end up just introducing this Crud into the sand? I bought some thing called “Revive” and was going to give that a try. My plan was to let it do its thing, vacuum to waste, and then immediately change the filter over to sand.

I tested the chlorine overnight last night and it held at 5 (yes, I know that’s high) and the CC was .5 I think. PH was 7.4, alk 120 (that seems weird because when the pool store tested it, it was fine), and CYA 53. I just got my Taylor test kit and my readings from last night were legit the first ones I’ve ever taken so there could definitely have been some user error. Also, I’ve had perfect test results at a pool store when all this was going on last year.

The water LOOKS great! Clear, blue, sparkly, but all that Crud is always on the bottom after shocking or brushing. PLEASE HELP ME! What do I do?!

 

[MITBeta]

You need to follow the SLAM Process now that you have your Taylor test kit.

Is your CYA reading from your K2006? If so, round up to 60. You can't read between the lines on the test.

Add your test kit and other equipment specifics to your signature.

 

[HeatherH]

Thank you. Are my specifics not showing up? I can see them on my end and I put them in and saved them.

 

[Burke_B]

This is all I see below your posts:

"17K fiberglass
Saltwater
Pentair Tagelus- Filter balls for last 2 seasons, switching back to sand soon."

 

[Lilypad]

Heather, I can see your PoolMath logs when I click on your name under your pic/avatar.

 

[PoolStored]

Hey! You are doing good. We can see your logs.

That may be detritus, sand, or dead algae.

First, when you do CYA test, fill to first line, glance. If the dot is "obscured" then that is the reading. If not, fill to next line. When, "at a glance" the dot is "obscured," you are done. That is your CYA. Let's assume 60 for now.

The best way to tell if you have algae is to perform and OCLT (Overnight Chlorine Loss Test). Let's do that, then go from there.

Perform the Overnight FC Loss Test (OCLT)

The Overnight Chlorine Loss Test tells if the SLAM is finished or if you need to start a SLAM. This article says how to do the OCLT.

www.troublefreepool.com

We will help you get here:

How Clear is TFP Clear? Let's See (Pics Only Please).

How clear should my water be? A very common question. Here is mine on a calm morning where I could finally vacuum. Yes I know, I'm still manually vacuuming. It took me 7 years to finally get an SWG, I'm working on a robot. :) So now let's see your water clarity.

www.troublefreepool.com

 

[IceShadow]

I haven't tried anything other than sand, but sand should work fine. It's supposed to get that stuff in it. Then you backwash when your pressure goes up by 25% over clean value, and it gets rid of the majority of it from the filter. You really shouldn't need to open it up and rinse out the sand more than maybe once a year. See here for how:

Deep Cleaning a Sand Filter

This post will walk you through the anatomy of a sand filter, and then provide a video at the end for how to deep clean your sand filter. The filter used in the photos and videos is a Hayward S180T top mount sand filter. The images are of a similar filter. Obviously not all filters are...

www.troublefreepool.com

I don't have a lot of experience with the balls in the sand filter, but I figure sand is supposed to be used in a sand filter, so I stick with that, personally.

You can stick to the 10ml test for chlorine. It's precise enough for what you want to do.

I agree with raising the FC up to about 10 or so and then doing an Overnight Chlorine Loss Test to see if you're fighting algae, or if it's just some crud that's blowing into the pool.

 

[Wobblerlorri]

Look at the FC/CYA Levels to see what level FC you should maintain for a CYA of 60. Bring your FC up to the middle of that range, then do an Overnight Chlorine Loss Test on your pool. That will tell you whether you have algae eating up your chlorine, and whether you need to do a SLAM Process. I'm betting you will.

If you do end up having to do a SLAM, be sure to lower your pH to 7.2 before you start. Don't worry, we'll get you to TFP clean, clear and beautiful blue!