A pool that hates chlorine

[RLP]

I guess I'm just trying to gauge rougher numbers in the beginning - did it drop 5 or 10ppm - and save my drops!


I am not... just swirling the vials.

Im not sure what the best course of action is for the autocover. I have an auto retractable Coverpools cover, and have wondered about that. Mine rolls up on the reel, and stays wet, even through the winter.

It could be dangerous to swim under it though.

I think I would complete the slam with the cover opened, then do an elevated chlorine dose, like a mustard algae treatment , with the cover closed, than another oclt after that. Maybe others can chime in.

I don't think you would lose 5 ppm accuracy with the smaller test. Probably less than that.

But you should really get the speed stir. It lets you replicate the test quite consistently and accurately.

 

[kul]

The pool essentials chlorine from Walmart does have a date along the bottom. It will read something like 23 186 etc. I just came back from buying several gallons with that date, so it should be on there where you are purchasing it as well.

 

[FrankieKat]

The pool essentials chlorine from Walmart does have a date along the bottom. It will read something like 23 186 etc. I just came back from buying several gallons with that date, so it should be on there where you are purchasing it as well.

Okay... that's very interesting! Some of the ones I bought a week or two ago were numbered as 23 170 (June 20, 2023?)... however some I just bought yesterday were 23 053 (Feb 23??). Does that mean I've been hoodwinked here? Or it's my fault for not checking. Okay... well... lesson learned.

 

[kul]

When I went today, I noticed they had about half old ones from maybe April and the newer ones (23 186) were in front. I think most people just pick up without looking because they don’t know to look. I bought all the 186s and left the oldies.

 

[JupiterFL]

Chlorine Date Code Decoder - Further Reading

www.troublefreepool.com

 

[FrankieKat]

When I went today, I noticed they had about half old ones from maybe April and the newer ones (23 186) were in front. I think most people just pick up without looking because they don’t know to look. I bought all the 186s and left the oldies.

Well, I was one of those dummies yesterday! Lesson learned!

 

[BoringDamo]

+ 1 gallon 10% liquid and ~27 oz 52% hypochlorite granules (+ ~12ppm FC)

Just want to check something here (or did I miss something??).
What type of hypochlorite granules are you adding?

When you add anything granular it adds something else, eg stabiliser (dichlor), calcium etc.
I want to make sure you understand what you are adding and that you aren’t unknowingly adding more CYA by using dichlor.
We normally say only use liquid chlorine as that is the only form that is chlorine only.

As an example, 27oz of dichlor (stabilised hypochlorite) would raise FC 6.2 in a 18000 gallon pool, but would also raise CYA by 5.7.

 

[FrankieKat]

Just want to check something here (or did I miss something??).
What type of hypochlorite granules are you adding?

When you add anything granular it adds something else, eg stabiliser (dichlor), calcium etc.
I want to make sure you understand what you are adding and that you aren’t unknowingly adding more CYA by using dichlor.
We normally say only use liquid chlorine as that is the only form that is chlorine only.

As an example, 27oz of dichlor (stabilised hypochlorite) would raise FC 6.2 in a 18000 gallon pool, but would also raise CYA by 5.7.

I'm using the HTH Pool Care "Cal Hypo" Shock (52% calcium hypochlorite) which claims that it "sanitizes without adding cyanuric acid (CYA) to prevent overstabilization or chlorine lock". That's what I was going on... but if that's wrong I'll stop using it.

 

[BoringDamo]

I'm using the HTH Pool Care "Cal Hypo" Shock (52% calcium hypochlorite) which claims that it "sanitizes without adding cyanuric acid (CYA) to prevent overstabilization or chlorine lock". That's what I was going on... but if that's wrong I'll stop using it.

That’s fine for not adding CYA but it is adding calcium. I can’t remember what your levels were but high calcium can also be an issue.

IMO you should only use liquid chlorine.

 

[FrankieKat]

That’s fine for not adding CYA but it is adding calcium. I can’t remember what your levels were but high calcium can also be an issue.

IMO you should only use liquid chlorine.

Got it. Last check the CH was a little bit high, so that's a good point. I'd just been mixing them since the granules are a bit more cost effective is all (especially in light of my buying a bunch of dusty liquid chlorine). I'll stick with the liquid going forward.

SLAM UPDATE:

7/14 2:15 PM:

• Weather hot - 91 degrees F and full direct sun. Cover still open.
• FAS-DSD (10mL): 25 FC, ~0.5-1 CC
• Previous SLAM level: 31ppm - 25ppm = lost 6ppm over 3 hours.
• + 1 gallon 10% liquid (+ 5.6 ppm FC)
• Current SLAM Level: 30

7/14 5:15 PM:

• Cover open, full direct sun all day
• FAS-DSD (10mL): 22.5 FC, < 0.5 CC
• Previous SLAM level: 30ppm - 23ppm = lost 7ppm over 3 hours.
• + 1 gallon 10% liquid (+ 5.6 ppm FC)
• Current SLAM Level: 28

7/14 9:15 PM:

• FAS-DSD (10mL): 15 FC, 0.5-1 CC
• Previous SLAM level: 28ppm - 15ppm = lost 13ppm over 4 hours.
• + 2 gallons 10% liquid, 18oz calcium hypochlorite (+ 15 ppm FC)
• Current SLAM Level: 30

Water is considerably clearer compared to 24 hours ago. The pool sure is smelly to be around though!

 

[FrankieKat]

7/15 8:30 AM:

• FAS-DSD (10mL): 16 FC, 0.5-1 CC
• Previous SLAM level: 30 ppm - 16 ppm = lost 14 ppm over 11 hours.
• + 2 gallons 10% liquid, 15 oz calcium hypochlorite (+ 14 ppm FC)
• Current SLAM Level: 30

So it dropped from 30 ppm to 16 ppm overnight. Would this indicate that whatever I'm fighting is alive and well and fighting back hard? Water is pretty much crystal clear again and FC is < 1 ppm.

It's going to rain all day and much of the weekend. Should I close the cover?

 

[drsipe]

It sounds like you have algae hiding in the pool, I would not cover the pool during the rain, but you need to test and maintain your FC at SLAM level.

Some advice that may help:

If you have a ladder, remove the ladder and clean with bleach or liquid chlorine, do not re-install until the SLAM is over
If you have a light, pull the light and clean the light and niche with bleach or liquid chlorine, do not re-install until the SLAM is over
Remove anything that you can that touches the water and clean with bleach or liquid chlorine, do not re-install until the SLAM is over
Brush the walls daily
Brush any little nooks like around the frame of the skimmers (I use a grout brush, it looks like a large tooth brush to get between the trim and the skimmer box)
Brush the skimmer weir

Algae is a very determined foe, it's much easier to keep keep at bay than to irradicate. It may seem like you are losing the battle, but if you keep to the process it will work and you will get to the TFP crystal clear water.

 

[FrankieKat]

It sounds like you have algae hiding in the pool, I would not cover the pool during the rain, but you need to test and maintain your FC at SLAM level.

Got it. It's going to rain *a lot* aparently, but makes sense to leave it open. It smells like a chlorine gas factory next to the pool so probably bad idea to keep that all trapped under the cover!

If you have a ladder, remove the ladder and clean with bleach or liquid chlorine, do not re-install until the SLAM is over
If you have a light, pull the light and clean the light and niche with bleach or liquid chlorine, do not re-install until the SLAM is over
Remove anything that you can that touches the water and clean with bleach or liquid chlorine, do not re-install until the SLAM is over.

I don't have a ladder but do have three LED lights on the side of the inner wall. I don't know of they are easily removable or just one single sealed piece. This pool is 3 years old so these would be a new design. At the very least I'll try to brush around them.

Brush the walls daily

I've been running my Dolphin S200 fairly continuously and it climbs and brushes the walls pretty thoroughly. I've been cleaning its filter daily as well. Do you think that would be sufficient?

Would you suggest back washing the filter often as well?

Brush any little nooks like around the frame of the skimmers (I use a grout brush, it looks like a large tooth brush to get between the trim and the skimmer box)
Brush the skimmer weir

Got it! That's one place I haven't really inspected all that well. I'll brush that throughly (once the monsoon stops).

Algae is a very determined foe, it's much easier to keep keep at bay than to irradicate. It may seem like you are losing the battle, but if you keep to the process it will work and you will get to the TFP crystal clear water.

I can tell! I can't believe it could still be surviving after all of this chlorine! It's also interesting that it can be so alive and well when the water is perfectly clear.

I was also looking at pictures of the pool last year and noticed that the water was never as clear as it is now so perhaps they've been with me for a while but flourished while the pool was covered and winterized.

Will keep the SLAM going.

Thanks so much for all of the help!

FK

 

[kul]

You’re doing all the right things. Hang in there!

 

[BDY]

Open and clean the autofill too if you have one - that was my algae hiding place

And any vacuum ports or water features

 

[Mdragger88]

Water is considerably clearer compared to 24 hours ago. The pool sure is smelly to be around though!

That’s the cc’s you’re smelling - that means the chlorine is killing stuff!
Be sure to do all the things
post a pic of your lights
*Check & scrub every nook & cranny where algae may hide (light niches, steps, drain covers, ladder handrails, skimmer throats/weirs, abandoned lines, autofill, overflow drains, etc.)
*If water can go there, algae can thrive there.
*Run slam level water through all water features & lines for at least a couple hours a day during the SLAM Process.
*Brush & or vac daily (this breaks up biofilms that algae uses to protect itself from chlorine)
*Backwash/clean filter when pressure rises 25%over clean pressure.

 

[RLP]

My Dolphin S200 only gets 30-40% of the walls during a cycle. I would let it run 3 or 4 times a day.

Post a picture of your lights.

 

[FrankieKat]

My Dolphin S200 only gets 30-40% of the walls during a cycle. I would let it run 3 or 4 times a day.

Yeah, I re-start it every time I check now, which is 3-4 hours.

Post a picture of your lights.

Attaching pictures of the lights!

Open and clean the autofill too if you have one - that was my algae hiding place

And any vacuum ports or water features

No auto-fill, vaccuum ports or water features. The pool itself is fairly straightforward - rectangular, vinyl lining, no ladders or anything in the water except for the three lights, four jets and the two bottom drains. See attached pics (that I took while it was raining hard).

That’s the cc’s you’re smelling - that means the chlorine is killing stuff!

Yes!!

post a pic of your lights

Done!

*Check & scrub every nook & cranny where algae may hide (light niches, steps, drain covers, ladder handrails, skimmer throats/weirs, abandoned lines, autofill, overflow drains, etc.)
*If water can go there, algae can thrive there.
*Run slam level water through all water features & lines for at least a couple hours a day during the SLAM Process.
*Brush & or vac daily (this breaks up biofilms that algae uses to protect itself from chlorine)
*Backwash/clean filter when pressure rises 25%over clean pressure.

The pool is only 3 years old so fortunately no abandoned lines or anything that should be aging. The filter pressure is at about 18 psi with the max being 20 so should be good.

Will do the rest of these things today and scrub scrub scrub!

 

[RLP]

Are you pulling the dolphin after every cycle and rinsing it and the filters off? I would.

Is this the light?

 

[BDY]

If you can pull any drain covers safely that’s been known to be a hiding spot