Dark swampy green pool TF-100 reagent test

[ajw22]

1. I am targeting CYA 30.
It's my understanding that in general pools chlorinated with tablets or liquid chlorine should have CYA up to 40ppm, so 30 is a great starting point as CYA can only grow over time?

CYA 30 is best for the SLAM process.

2. Then, following the 7.5% rule, the FC should be 2.25ppm?

You do not want to run your FC at the minimum. The minimum is a never drop below number.

The Free Chlorine and Cyanuric Acid Relationship

Managing your cyanuric acid and Free Chlorine levels is key to stabilizing your pool. Learn how these two items affect each other.

www.troublefreepool.com

3. But this is the level I should maintain when the pool is healthy but since that's not the case right now, I will maintain it at 12ppm to purge the contamination/algae?

Correct.

4. This pool isnt in my home - pretty far away from it so I can only visit it early in the morning, before work and maybe twice at night after work.

Do the best you can as often as you can.

So I can add the LC once early in the morning or twice at 6-7PM and 9-10PM every evening

Although I have CYA 30, isn't it still better to add LC in the evening, so I add LC twice every evening ~3 hours apart and never early in the morning when the sun will beat on the FC anyways?

No, that lets the algae grow and party during the day.

 

[plnewb]

Today will be my 3rd day of SLAM but I wanted to set my own expectations:

1. I have removed the DE filter grid since day 1, so the pool is circulating 24x7 without anything being filtered
2. In this scenario do I still expect to see clear water soon if I keep targeting FC=12 @ CYA 30, pH 7.2?
3. I expect to see dead algae (which I assume is white?) at the bottom of the pool but the water itself should turn clear even if I have no filter?
4. If that's true - I can then vacuum the bottom to waste (or let the Hayward pool vac do its job)
5. Only after I exit SLAM, then I install the DE filter grid, pour in the slurry and all that stuff

 

[ajw22]

Your water will not clear without filtering at some point.

The water should change color as the algae is killed.

 

[plnewb]

The water should change color as the algae is killed.

Does it still stay green?

Or does it change From green to cloudy white (as if I had DE leaking)?

 

[ajw22]

Does it still stay green?

Or does it change From green to cloudy white (as if I had DE leaking)?

Water chemistry is not that precise to predict.

 

[plnewb]

Water chemistry is not that precise to predict.

I empathize, but I am looking for some guidance about the change in color and when I should drop the DE Grid into the filter casing and add DE to actually initiate the filtering process

The water should change color as the algae is killed.

I do notice the pool turning from a dull dark green to a more shiny light green but visibility below 7" from the surface is still 0. When I take water samples for testing, I am always a bit afraid that megaldon will rise up and bite my hands off - is there any chance that the water might clear up a bit without the filter in the loop yet?

 

[ajw22]

I empathize, but I am looking for some guidance about the change in color and when I should drop the DE Grid into the filter casing and add DE to actually initiate the filtering process

As soon as you have a day to babysit the filter and see how long it can run before needing to be backwashed.

Continuous filtering during the SLAM process is best. The more filtering you can get done the quicker things will clear.

I do notice the pool turning from a dull dark green to a more shiny light green but visibility below 7" from the surface is still 0. When I take water samples for testing, I am always a bit afraid that megaldon will rise up and bite my hands off - is there any chance that the water might clear up a bit without the filter in the loop yet?

Not likely. But you are doing a science experiment as most people filter continuously and clean the filter as necessary.

 

[plnewb]

As soon as you have a day to babysit the filter and see how long it can run before needing to be backwashed.

I have some questions and concerns about placing a freshly cleaned DE grid into swampy water and feeding DE slurry through the skimmer (is there a better technique for feeding the filter DE slurry when the pool's all swampy water?) but those can come later.

The filter (with no DE grid) pressure is at 14 PSI with the VSP running full blast. It maintains 14 PSI down to 3200 RPM

1. If I now insert the freshly cleaned DE grid without the DE slurry, I expect the PSI to go up?

2. Then once I add the DE slurry, I expect the PSI to go up even more?
3. But then I have on clue at what PSI I should consider backwashing the grids?

I am not opposed to taking the grid out of the casing and hosing it down every other day, although I will lose 5-6 lb DE each time. The DE was gross and green and smelled like heck the last time I took it out and backwashing wasn't doing much - there was caked on DE between the grids and the filter ran at 25-30 PSI

 

[ajw22]

Do not run the grids without DE for longer then it takes for you to get the pump running and get to the skimmer to pour in the DE.

The pressure will rise as the filter clogs.

The usual recommendation is to clean the filter when the clean PSI rises by 25%. That can happen quickly during the SLAM and I think you can go longer if you monitor the flow and clean the filter when you feel the return flow dropping or PSI gets around 28-30.

Show me pics of your filter and type of valve you have on it.

 

[plnewb]

Do not run the grids without DE for longer then it takes for you to get the pump running and get to the skimmer to pour in the DE.

Why not?

 

[proavia]

Why not?

Without adding DE shortly after starting the pump, the grids will get clogged with debris and dead algae. Withput DE on the grids, it is difficult to impossible to remove this debris and dead algae as it gets jammed in the grids. A few minutes is fine to run the pump while adding the DE slurry.

Just follow what @ajw22 suggested and get on with your SLAM Process.

 

[plnewb]

Without adding DE shortly after starting the pump, the grids will get clogged with degris and dead algae.

Right - contamination of the grids with debris and dead algae was the reason why I'm circulating without the grids and I was really hoping I would get to some clear water without them

Do not run the grids without DE for longer then it takes for you to get the pump running and get to the skimmer to pour in the DE.

Why don't I, with the pump off:

1. Pour DE slurry into the skimmer
2. Load the DE grids into the filter
3. Start the pump

Are there any risks with doing #1 before #3? It can take me upto 30 minutes for #2, if that matters at all

I am just trying to think of ways to reduce the contamination of the grids with debris and dead algae

 

[ajw22]

Why don't I, with the pump off:

1. Pour DE slurry into the skimmer
2. Load the DE grids into the filter
3. Start the pump

Are there any risks with doing #1 before #3? It can take me upto 30 minutes for #2, if that matters at all

I am just trying to think of ways to reduce the contamination of the grids with debris and dead algae

Because without the pump running to pull the DE slurry into the pipe the slurry will end up leaking in the pool.

I don't bother making a slurry. I pour DE directly into the skimmers with the pump running.

You are overthinking things and making more work for yourself.

 

[plnewb]

You are overthinking things and making more work for yourself.

I tend to do that! I'm lucky I have you all to help me think things through.

Background:

I had the pool at pH 7.2, FC at 2.5, CC at 2 last night (assuming CYA: 30, TA: 50) at which point I added 2G LC to target 13 FC
This morning (after 10 hours) I have FC at 2.5, CC at 0.5 (or less) so I added 1G LC (assuming CYA:30, TA: 50) to target 12 FC

What I am confused about is the low CC - this is near a "high quality water" level!

I assumed that when the FC kills organic material, the CC goes up (and the FC drops proportionately as it gets used)?

1. Is my understanding of CC wrong?
2. If not, then CC isn't a great indication of Algae and this low CC indicates I don't have any other contamination other than Algae?
3. In that case, I won't be doing the CC tests any further at all, saving myself some reagents, instead I will focus on clearing the water and no overnight drop in FC first

 

[plnewb]

Show me pics of your filter and type of valve you have on it.

The filter is a PacFab Nautilus FNS 48 DE Filter and uses aftermaket PFG2448 grids.

Attached the closest pic I could find that matches it

PFG2448 grids: Amazon.com

The "air escape" looks like this (just cleaner - cleaned by me using a toothbrush) https://poolownersguide.files.wordpress.com/2017/03/2-dirty-de-filter-grids.jpg

The Manual Air Relief Assembly looks like this: https://images-na.ssl-images-amazon.com/images/I/31mtlSqfxkL.jpg

I will have it open after loading the grid into the filter housing until water starts to come out of it to ensure air is purged and the grid is all under water.

 

[ajw22]

I1. Is my understanding of CC wrong?
2. If not, then CC isn't a great indication of Algae and this low CC indicates I don't have any other contamination other than Algae?
3. In that case, I won't be doing the CC tests any further at all, saving myself some reagents, instead I will focus on clearing the water and no overnight drop in FC first

Yes, your understanding of CC is wrong. CC is not proportional to the quality of the water. It is just one of the indicators of algae and unsanitary water. You can have algae and unsanitary water with 0 CC.

I think you are saying that you have a slide valve to backwash the filter and not an MPV.

Slide Valves - Further Reading

www.troublefreepool.com

 

[plnewb]

New plan:

1. Turn the pump off
2. Load the DE grids into the filter
3. Pour DE slurry into the skimmer and call my aunt standing by to start the pump right away

If this is the best plan so far, I can get this done after work this evening

I think you are saying that you have a slide valve to backwash the filter and not an MPV.

Yes, it's a Push/Pull Slide Valve Piston assembly 27-3241. I would love to get my hands on a manual for it so I can get the OEM measurements BTW (if you, or someone here has a scan of it)

 

[proavia]

You are overthinking things and making more work for yourself.

This 100%
Plus overly complicating it too.

Just

• shut the pump off
• install the grids in the filter
• start the pump, walk (don't run) to the skimmer
• put the DE into the skimmer

 

[ajw22]

Yes, it's a Push/Pull Slide Valve Piston assembly 27-3241. I would love to get my hands on a manual for it so I can get the OEM measurements BTW (if you, or someone here has a scan of it)

See the attached manual.

 

[plnewb]

See the attached manual.

I have the older one that looks like this:

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O-Ring Kit for Backwash Slide Valve 2" replaces Pentair 261047 261165 263064 | eBay

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You wouldn't happen to have the manual for that one, would you