Ugly green winter pool with high CYA. Help!

[doxtyp]

Hello, community!
Due to various circumstances, we haven't touched our pool since last year. As the results it has turned into a green swamp with mosquitos, ducks and all!
It's bean shaped, so kinda funky to calculate the volume. I am estimating 11,000 gallons. Not sure about lining. Vinyl, I think?

Measurements today: (using Taylor 2006 FAS-DPD)
FC - 0
pH -8 (or more, it's all purple)
CYA - 90

Action plan from my TFP reading:
1. CYA dilution test to confirm high reading. Or perhaps double checking at local pool shop. I am also afraid my test kit is old.
2. Partial drain for high CYA? (honestly with drought in California, would hate to do it unless really necessary. It has lost some water already with evaporation. CYA last year was in triple digits but got diluted with rains a bit).
3. Wash filter (or replace if super dirty)
4. SLAM per protocol (any recommendations for cheap liquid chlorine in Bay Area are welcome).

Any thoughts? Thank you all in advance! This forum has been such an invaluable resource.

 

[AK-]

1. CYA dilution test to confirm high reading. Or perhaps double checking at local pool shop. I am also afraid my test kit is old.

The CYA reagent has a quite long shelf life. Even if it is a little degraded your test results is probably better than pool store. As long as it wasn’t above the 90 line you don’t need to dilute, but no reason not to either.

2. Partial drain for high CYA? (honestly with drought in California, would hate to do it unless really necessary. It has lost some water already with evaporation. CYA last year was in triple digits but got diluted with rains a bit).

The recommendation is to dilute, but you could look into a reverse osmosis service (expensive and still wastes a lot of water).
Running at 90 CYA is possible, but you have to be willing to use a lot of chlorine just keep at that level. You would need about 4 gallons of 10% LC just to get to SLAM level and countless others to maintain it. Also the high the FC the higher the loss to sunlight.

3. Wash filter (or replace if super dirty)

What type of filter do you have?

 

[doxtyp]

What type of filter do you have?

Thanks for your thoughts. I have Pentair cartridge filter.

 

[wireform]

Since your signature isn't filled out there's no telling what size pool and equipment you have. With high CYA the fight will be using many gallons of chlorine. You may want to calculate what the water costs for a complete drain and fill as it may be close to a wash using lots of chlorine.

 

[AK-]

Thanks for your thoughts. I have Pentair cartridge filter.

No need to replace it unless it is damaged.

I have a spare cartridge that I swap if I have to clean the cartridge mid-season. That way I can take my time cleaning it without having to shutdown my filter.

 

[doxtyp]

An update and couple of questions to the community.

I drained about half of water and replaced it. CYA dropped to 30 (yay).
pH with fresh water was >8, so I added muriatic acid per chart. pH became around 7.2-.4
I’ve been SLAMing with liquid chlorine (10% from HD or Walmart) ever since. Cleaned filters out as well. It’s gotten better but still very cloudy.
Readings this AM (6/14, 9am):
FC 12.5 (I added 4 gallons of LC last night)
pH <7

I am assuming that all the organic material is consuming LC like crazy.
I think pH is not reliable at this point so I won’t chase it.
I am also not sure whether to add LC only at night or in the AM as well - it’s been very sunny.

Does this all make sense?




Does this all make sense?

 

[wireform]

Dox
Once you have the PH down before slam there's no reason to check it again until slam is DONE. As far as slam you must be absolutely sure that you achieved slam level by checking 20 minutes later but if it hasn't reached slam keep topping it up until it maintains it and then every three hours check it so you can replace what has been burnt off.

 

[IceShadow]

You need to keep up the FC levels, whether the sun is on it or not. Check often, up to once an hour or so and add more chlorine to get back to SLAM level as needed.

 

[doxtyp]

Thank you! I’ll check more often.

Out of curiosity - is it possible to overdo chlorine level? What if it goes too high?

 

[AK-]

Out of curiosity - is it possible to overdo chlorine level?

Yes, but if SLMAming and having trouble to maintain FC not going to be an issue. Either way some extra ppm over a short period of time is unlikely to cause any significant damage (discoloration/oxidation). How much some extra ppm is depends a your CYA, the higher the CYA the higher the too much chlorine threshold is.

What if it goes too high?

Depends on how much is too much… sunlight alone can deal with the excess in a reasonable amount of time in most cases… if there is a concern about bleaching liner/plaster or damaging equipment then there are aways described on the wiki to neutralize chlorine.

 

[AK-]

As a side note, because concentration of LC it is much more difficult to overt shot chlorine when using LC than any form of granular shock (Dichlor/Cal-Hypo).

 

[doxtyp]

Thank you. I’ll keep working on that FC.

I may have a new nemesis though. I’ve been brushing but can’t see the bottom due to cloud water. I finally was able to fire up my Polaris 380 cleaner (it’s been acting up) and it started collecting bunch of small leaves from the bottom. I am suspecting that unless those are cleared, I won’t be able to clear the water. Does this sound correct?

Part of the problem is that my Polaris is half dead (stops randomly, gets stuck). I may need to order another one. In the meanwhile, could anyone recommend an efficient way of cleaning the bottom of leaves and junk?

 

[kimkats]

Well at least the water is not green any more so you are on the right track! Good job so far!

Leaves on the bottom-get one of the deep pool nets. If you can stand it get in the pool (burrrrrr) and blindly push the net along the bottom. Bring up the net and dump it on something like a tarp so it does not stain the pretty decking and coping. You can also get one of these: https://www.amazon.com/Poolmaster-28300-Sucker-Swimming-Vacuum/dp/B0007PZN9Q Just know this adds water to the pool so you need to be ready for that.

 

[doxtyp]

Well at least the water is not green any more so you are on the right track! Good job so far!

Leaves on the bottom-get one of the deep pool nets. If you can stand it get in the pool (burrrrrr) and blindly push the net along the bottom. Bring up the net and dump it on something like a tarp so it does not stain the pretty decking and coping. You can also get one of these: https://www.amazon.com/Poolmaster-28300-Sucker-Swimming-Vacuum/dp/B0007PZN9Q Just know this adds water to the pool so you need to be ready for that.

Oh wow this thing works surprisingly well! Immediately collected bunch of leave without even seeing the bottom. Thanks so much for your recommendation. What a magical device that is

 

[kimkats]

This will speed up the SLAM two ways. Get stuff out and exchanging water! So glad it is working for you!