To slam or drain first? CYA 100

[Battaduck]

Hi all! New pool owner and first time poster here needing some help! So, I think the pool guy who was 'taking care' (ha!) of things before we bought the house really screwed us. As of now here are levels,

FC 7 ppm (we added a bunch of liquid form, it was previously at 1)
CC comes up at 0?
Ph 7.8
TA 120
CH 425 (used a Hach test strip for this)
CYA 90-100


So, overall our water is pretty clear. But, in between us firing the pool guy and waiting for our test kit and equipment to come in, we got mustard algae. I can add a photo later, but we're pretty sure its algae and not pollen. Its on the sides in the shade, under the ladder steps, around the light and we cant brush any of it off. The pool guy's idea of maintenance was just a big pile of chlorine tabs in the corner of the waterfall, and maybe skimming out leaves every 2-3 weeks. We kept him on for 2 months before we got rid of him. We haven't added any stabilizer in any way, so I can totally blame him for that, right? Lol

Ok, so my question is, should we even bother trying to slam with the CYA being so high? Or should we drain a % of the water out and then do it? Keeping in mind it would be a challenge to drain a significant amount. Ahhh, help please!

 

[Richard320]

Bite the bullet and drain to 50 CYA or less. Yes, it's a PITA, and yes, your water bill will be big, but maintenance is a whole lot easier with reasonable CYA and eradicating algae is going to be really hard unless you deal with it.

 

[Battaduck]

Ok, you're confirming what I know but don't want to accept. As a follow up, would getting the CYA down to 70 ish be acceptable? Or is 50 what we should really get to? Just trying to see if there is any leeway here.

 

[Richard320]

Ok, you're confirming what I know but don't want to accept. As a follow up, would getting the CYA down to 70 ish be acceptable? Or is 50 what we should really get to? Just trying to see if there is any leeway here.

Go look at poolmath. Set it up to plaster, TFP, bleach and then go back up and set CYA to 70. See what shock level and mustard shock level are. Remember, you want to keep it a shock level until you pass the 3 tests and lastly take it up to mustard shock level and keep it there for 24 hours. Pool School - Mustard Algae

The savings in bleach will probably cancel out the cost of the water.

I'd call the water company and see if they might allow swimming pool refills every so many years at standard rates rather than the higher tiers. Or at least alert them to what you're doing (Tell 'em it's Calcium buildup or pool resurfacing) and maybe they won't send you a threatening letter or come stick a restrictor on your meter.

 

[Battaduck]

Alright, it's happening today. Hopefully we can get it done without any issues.

 

[Oly]

So how is it going? Keep us posted Battaduck.

 

[Battaduck]

Draining went without a hitch yesterday. We rented a pump from Home Depot and it took about 5 hours to drain half the pool. We started refilling right after but turned it off when we went to bed and continued it early this morning. Almost done with that, soon I'll test levels and start SLAMing. Will update on how it goes soon. Hopefully can get this done right the first time and not have the mustard algae come back.

 

[Richard320]

Excellent!

I suggest you load up on Motrin now and get busy with the brush. It will a) break the protective biofilm off the algae on the walls and b) mix the old and the new water thoroughly. Especially if you own a wall whale brush.

 

[Battaduck]

Haha, thanks for the tip. I think I'll make my husband do the harder physical labor.

How soon can I start testing levels? Pool is almost full.

 

[Richard320]

Haha, thanks for the tip. I think I'll make my husband do the harder physical labor.

How soon can I start testing levels? Pool is almost full.

Let things mix for half an hour or so with the pump on. And like I said, brushing speeds it along.

 

[Battaduck]

Quick update, today is 2nd full day of shocking. Was slightly discouraged yesterday, since algae looked the same. But today, some of it is definitely a browner shade of yellow than before. So I'm taking that as a good sign. We've been brushing as much as we can, keeping FC level up and filter is going nonstop. Fingers crossed we win this battle soon!

 

[Richard320]

Quick update, today is 2nd full day of shocking. Was slightly discouraged yesterday, since algae looked the same. But today, some of it is definitely a browner shade of yellow than before. So I'm taking that as a good sign. We've been brushing as much as we can, keeping FC level up and filter is going nonstop. Fingers crossed we win this battle soon!

Cleaning up a mess always takes longer than making it. It didn't turn into a swamp in just a couple days. so it'll probably take a week or ten days to clear it up. Make sure any organic debris is out, even if it means vacuuming blind.

 

[Battaduck]

Ok, got it. We're being super patient with it and keeping up shock level. Just wondering if there are any obvious signs that it is working? The water was always clear, its just algae on the walls. Its definitely not as bright yellow as before, but isn't coming off when we brush or anything. Also, every time I test FC and CC, CC has consistently been 0.

 

[Teald024]

Take a pic of the area every day. You eyes may not be able to see the difference, but comparing the pics day to day should reassure you that your hard work is paying off.

I assume you retested your CYA after the refill to verify. And then use that new CYA # to set your SLAM level.