Cleaning up mess previous owners left me

Fndr70

Member
May 22, 2019
22
Pennsylvania
Hi everyone, new guy here.

I bought a house last October, and the previous owners had covered the pool. I don't think the water was in very good shape before getting covered. Cover way way too big for the pool, and was constantly blowing off over the winter. I didn't have much time to deal with it, so I'm sure the water got contaminated.

Anyway, fast forward to a week ago, I took off the cover to find the pool looking like the first pic. The water was basically black. My parents had a pool when I was younger and I remembered, sorta, what my dad always did so first thing I did, even though I couldn't really see anything, is get as much Crud off of the bottom as I could. Then I remembered he always shocked it, so I went to the Lowe's down the road (closest place that sells pool chemicals) and got the Clorax brand Shock, and the Clorax brand test kit. (in hind sight that test kid seems like a piece of junk, but I didn't know any better).

Anyway, I shocked the pool 3 times (each with a 1lb bottle of their shock stuff) and it got to the second pick. Progress, right? Then I used their test kit and all my levels (it tests hardness, total chlorine, free chlorine, ph, alkalinity, and stabilizer) were all zeros. That seemed impossible, but the app that goes along with the test kid said to get the alkalinity up first, so I did and now it's at 180, which it reports as a bit high for my pool size (12500 gallons). next I added stabilizer, and that is not at 50, which is in the ideal range for my pool, but on the low end, according to the app. I then called their help line to find out what to do next, and they suggested dumping a gallon or two of liquid chlorine in (I did one), and buying the chemical to get the pH up. So now I have the following levels and the pool looks like picture 3

Hardness - 0
Total Chlroine - 5
Free Chlorine - 10 (although the test strips max out at 10 so it could be higher)
pH - 6.8
Total Alkalinity - 180
Stabilizer - 50

I'm not confident in the test strips because the readings increase the longer you wait, and it's unclear when you're supposed to consider the test "done".

So anyway long story short, what do I do next? I looked around the site (was recommended by a friend) and I guess I have to do the SLAM process, right? I assume also get a reliable test kit?

The other issue I have is that I'm not entirely sure the filter works right. This is one of those Intex pools (so I'm tempted to just knock it down and put a swing set in for my kids cuz I feel like it will be july till this thing is usable), and the return stream seems to get weak after about 3-4 hours of filter operation. I've cleaned the filter out as best I can, and it seems like if I backwash the filter that brings the stream back up for another few hours. Whenever I backwash the water it dirty each time, but clears up about 30 -60 seconds after starting. Is it possible the water is just that filthy and requires that much backwashing? I know this is the algae forum but I also know a properly functioning filter is important.

Thanks!first.jpgsecond.jpgthird.jpg
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
20,540
Laughlin, NV
Welcome to the forum!
You need to SLAM Process. To do that, you need a proper test kit. I recommend the TF100 - Test Kits Compared
While you are waiting on your test kit, add 5 ppm FC worth of liquid chlorine each evening. Circulate the pool when you add that to mix it in but otherwise circulation will be difficult as it is overwhelming your filter.
Can you add a signature with a description of the pool and its equipment? See mine below for an example.
When you get your kit, do a full set of test results and post them here before you do anything.

I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.
 

Fndr70

Member
May 22, 2019
22
Pennsylvania
Thanks! I will do all of that starting tomorrow.

Just to make sure my math is correct.... assuming I have 13% chlorine, that means 130000 ppm right? 130000/5 = 26000:1 and my pool is 12500 gallons so 12500/26000 = about half a gallon each night?
 

Fndr70

Member
May 22, 2019
22
Pennsylvania
OK here are my #s. I got the Taylor K-2006 test kit

Free Chlorine - 19.5
Combined Chlorine - .5
Total Alkalinity - 170
Calcium - 40
pH - it's above 8.... the test showed redder than the max at 8
CYA - 90-100

Based on the documentation here, it looks like i might want to partially drain/refill the pool, huh?
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,001
Tucson, AZ
Yeah, a 50% water replacement would get your CYA to a more reasonable value. That shock powder you added at the start may have also been increasing the CYA.

Also, the pH will show artificially high when the FC is greater than about 10ppm.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,001
Tucson, AZ
Avoid dichlor by not using powdered chlorine, which could be dichlor or trichlor (also adds CYA) or cal-hypo (adds calcium).

Stick with liquid chlorine.
 

Fndr70

Member
May 22, 2019
22
Pennsylvania
So the CYA only came down to 70-80 after a partial drain/refill so I'm going to do that again. Seems to be most economical to get it down to the 40-50 range based on the chart.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,001
Tucson, AZ
Your current CYA level is reasonable. While the required FC level is higher, the daily losses to sun should be similar or even less. So I would not say that lowering it more is economical.
 

Fndr70

Member
May 22, 2019
22
Pennsylvania
OK, after draining a bit more (didn't see the reply that the 70 CYA was reasonable) my levels are -

CYA-55
Hardness - 30
Alkalinity - 90
Ph 7.4
FC 1.5
CC - 0

The water is cloudy (although I can see the bottom now, at least, with the fresh replacement water) so I'll proceed with a SLAM and see what happens.
 

Fndr70

Member
May 22, 2019
22
Pennsylvania
I did my first SLAM this morning. I used CYA of 60 before reading this.... I assumed rounding up was better.

Anyway, my FC is 26.5 (a little high.... guess I added a little too much chlorine), and my CC is 1.0.

So I should maintain the SLAM FC level through this whole process right? I won't be able to test more than 3-4 times a day.

Also are my other levels (TA and Calcium) OK?
 

DorsalSpine

Silver Supporter
Jul 8, 2013
382
Columbus, Ohio
They look good for now. Concentrate on the FC and CC testing for now. Test as often as you can. The goal is to keep the level up as long as necessary. If you let the FC level bounce up and down it will just take longer.
 

Mr Bruce

TFP Guide
Mar 24, 2014
2,350
Greenville, SC
If 3-4 is all you can manage then it's fine. Don't worry about anything other than FC and CC until you are done with the SLAM. You may never need to care what the CH is. TA is the last thing to worry about. (I think it's hillarious that's what the cheap Clorox test recommends "correcting" first.)