New pool owner - negelected for 15 months

[jeff.ridge]

We just bought a new house with a pool. It is a 16x32 vinyl in-ground with a sand filter. The house was vacant for 15+ months and, as you would expect, the pool was a swamp. I scooped out as much of the solids on the bottom as I could (and all the tadpoles!). The pool vacuum is not pulling up much anymore so I think the bottom is pretty clean at this point. Ammonia was confirmed with an aquarium test kit and neutralized with bleach. CYA brought up to 30 and started to SLAM.

I scooped out as much of the solids on the bottom as I could (and all the tadpoles!) and started to SLAM with bleach. It seems to be going very slowly, so I'm just looking for confirmation that I'm on the right track.

Last test from this morning. (TF-100 kit)
FC: 10 (added 1/2 gallon of bleach to bring it up to 12 for SLAM)
PH: 6.8
TA: 60
CYA: 30
CH: 175

Before:


Current:

 

[JimMarshall]

When you have such a high organic load like you did, it's a slow process to neutralize all of it.

A couple tips: as your water clears, if you see ANY debris you can remove, remove it. You want that free chlorine working on algae, not on sticks and leaves.

2: Take a picture every day, or every couple days, from the same spot. Sometimes it seems like you aren't making any progress, but in reality you just aren't realizing it. Having a photo to compare helps your brain realize it is working.

3: Be sure to be cleaning your filter when, and only when, you see a 25% rise in filter pressure.

You're doing great. Happy SLAM-ing!

 

[Newdude]

^^^^^^. All of that.

Also, belated Welcome !!! This is your first rodeo but you now have the collective knowledge here that’s been to 1000s of rodeos.

We’ll ride along with you.

 

[mknauss]

Welcome to the forum.
You say it is going slowly. At what point did you start the SLAM Process? That is after eliminating the ammonia and adding CYA.

 

[Mike1162]

What's the filter pressure after backwashing & how high are you letting the pressure get before backwashing.
x2 wondering the date you started the slam.

 

[jeff.ridge]

Pressure was starting around 23 and I would backflush at 28-30 daily or twice a day. Now that it has cleaned up quite a bit the pressure is rising much more slowly. I think it was at 25 this morning.

We started before we moved into the house, so we couldn't check as often as we should have. I suspect that is why it is taking longer. Now that we've moved in it has been a little over one week of constant attention.

Would adding DE to the sand filter help now that I'm not backwashing every day?

 

[mknauss]

One week is pretty quick with what you started with.

If your FC is not dropping much between tests then use some DE in the sand filter. Only do it when you can baby sit the filter. It can quickly plug off.

 

[Mike1162]

23 sounds a bit high for clean pressure.
You might want to try Deep Cleaning.

If the water isn't showing improvement 3 or 4 days after deep cleaning then I'd consider changing the sand. The general consensus here is that sand doesn't wear out but who knows what the previous owners put in there. HTH sand gets good reviews.

 

[jeff.ridge]

OK, I did a OCLT last night and the FC held steady at 11.5 between 10pm and 8 am this morning. CC is ZERO - not even a hint of pink.

Pool is still cloudy like the second picture in my original post. I did a 5 minute backwash last night and the pressure came right back to 23 psi. There was some cloudy water in the sight glass, but not nearly what I was seeing at the beginning. It ran clear for probably 4 minutes of the 5 minute backwash.

Do I have a filtration problem? Plan is to break the lines to the valve and do a deep clean and reinstall with unions this weekend.

Also, another datapoint... there are "rough" deposits on the sides of the pool that rubs off with some light pressure. I have just assumed this is "gunk" from the pool sitting, but could it be something different?

 

[mknauss]

The final stages of the SLAM Process with a sand filter can be slow. Doing a deep clean is a good idea if it has been awhile.
Have you tried using DE yet?
Rough liner implies scale.

 

[wireform]

You're doing great. Don't bother with any other tests except the FC and not even CC. As long as the FC isn't holding there's nothing else but just keep the slam. I'm a little leary about 23 psi clean pressure. Sand may be gummed up from previous owners potions. At minimum a good deep clean is in order but be prepared sand filters take the longest to bring the pool clear.