Need some help cleaning up a mess.

[dmartin]

Hello to all,

I just closed on a new house with a large ~30K gallon plaster indoor pool that probably has not seen any maintenance or chemicals in over 18 months. Initially the water was greyish green and had the following chemistry.

FC - 0 ppm
CC- 0 ppm
CYA - 3 ppm
PH - 7.8
Hardness 312 ppm (from pool store)
Alkalinity 103 ppm (from pool store)

After doing what amounted to about a 20% water change so that a leak could be fixed; I started the shock / slam process several days ago with the pumps running 24 hours with filter backwash as required. I maintained the FC levels at 12 ppm for the first 36 hours with almost no change in water color / clarity. I increased and have maintained 16 ppm FC levels with the water color now bleaching to a light blue grey, but still with heavy cloudiness. Even with a low CYA it has been relatively easy to maintain the chlorine levels in the pool. I have noticed the CC levels starting to creep up and are now at 1.5 ppm. Using the TF-100 test kit I have the following chemistry.

FC - 18 ppm
CC - 1.5
CYA - 3 ppm
PH 7.8

Water Temp 51f

I am thinking that the cool / cold water is slowing down the oxidation / cleanup process. I know my PH is a bit high but when I add the stabilizer it should drop my PH by 0.3 or 0.4 bringing it in to within acceptable ranges. Any ideas on how to proceed?

Thanks

 

[duraleigh]

I don't think you have a major problem and are doing most everything correct. Are you seeing a psi increase? You should be seeing some. You should also be seeing a slow, gradual improvement in the water clarity.

I think you are on the right track and would change very little.....just be patient.

Your CYA result of 3 is not correct.....anything less than about 20 ppm cannot be measured.

Do not bring your FC any higher. until we get a grip on your CYA, FC of anything above around 10 ppm is pretty aggressive and not really necessary.

 

[duraleigh]

Probably would have been better to stay under the old thread but let's keep your info under this one since it is started.

 

[dmartin]

Thanks for the feedback. I started this thread as some forums are rather picky as to what goes where so as to keep the sub forums on topic.

The CYA levels were done at the pool store using their digital lab and I am going off their print out. I have not added any water to the pool and have only been adding liquid 12.5% bleach so the CYA levels should not have changed from the first test. Currently I am only testing chlorine levels, and on occasion PH.

I am seeing a bit of a pressure creep on the sand filter but I am also back washing about every 24 hours. I have been brushing and vacuuming at least every 24 hours as well.

BTW thanks for the fast shipping on the test kit.

 

[duraleigh]

We would trust your own CYA readings from the TF-100 more than the pool store test but it is likely zero.

Backwash when your psi reaches 25% over clean pressure. no reason to backwash less or more.

It is normal for your CC's test to creep up, then back down as the SLAM process continues. There is no reason to test for them any more until your pool is virtually clear.

You're welcome about the shipping. :lol:

I think things are fine. Do not add anymore chlorine until you drift down to about 8-10 ppm or so.

Post a pic of your pool water when you can and, to confirm, it would be helpful to see your own CYA test.

 

[dmartin]

FC - 14
CYA - 0 per the TF100 test kit

Temp 52 f

One thing of note and I do not know if it makes a difference when I first started with FC target of 12 ppm I had almost no creep in levels or increase in CC. Its was only after I came up to 16 ppm that I started to see fluctuations and a noticeable drop in FC over a couple of hours. I am sure this process is normally done with pool water at a warmer temperature but I don't want to turn on the heat until I get it cleaned up.

Thanks for all the help.

18' x 32' 54" - 108"
[attachment=0:2qydjzzi]PoolPic-sm.jpg[/attachment:2qydjzzi]

 

[duraleigh]

The extra chlorine (16 ppm) is fine in YOUR case but it's not a standard we want to suggest. That pretty aggressive and, to cover all situations, staying around 10 ppm with 0 CYA is quite a bit safer. The colder water certainly slows things down but your pool water looks decent and I think you will be quite clear soon.

Keep running your filter, letting it do it's job. Are you brushing and/or vacuuming? I can't remember.

 

[danacc]

...Currently I am only testing chlorine levels, and on occasion PH.

I am seeing a bit of a pressure creep on the sand filter but I am also back washing about every 24 hours. I have been brushing and vacuuming at least every 24 hours as well.
...

No need to test pH until the slam is done. (If you are keeping FC around 10, you'll get accurate pH readings, but when you push it up above that the way you've been doing, pH will show artificially high. Note that most pools have CYA, and so their pH readings start becoming inaccurate at slam levels.)

Also, as noted, there is no need to backwash every 24 hours. Sand filters actually filter better when they're a little bit dirty, so your water should clear a little faster if you stop backwashing so often. Keep up with the brushing, you're doing fine. Nice pool!

 

[dmartin]

Interesting development,

Last night I checked my levels about 5pm local time and had 12ppm FC and 1.5 ppm CC. The levels had been staying very stable as I had not had to add anything to the water in almost 24 hours and was not loosing more than ~0.5 ppm every 24 hours. When I tested the water this morning the levels had changed to the point I ran the tests twice then took a sample down to the pool store to have them run their tests which came out the same. In about 12 hours time my FC ad dropped to 6.5 ppm and my CC had increased to 5 ppm. My PH had also shifted to 8.2 increasing from 7.8 pre SLAM. I addressed the PH with some acid bringing it down to 7.6 after letting the pool circulate for several hours and then I brought my FC back up to SLAM levels. Any idea what would have triggered the overnight FC drop when the levels have been very stable over the last few days changing very little? Keep in mind this is a indoor pool and nothing has changed environmentally.

Thanks to all.

 

[dmartin]

Bump,

CC levels are now less than 0.5 after another round back up to 16ppm FC. FC holding steady and has not dropped in at least 12 hours. Pool water still cloudy, and I can't see the main drain still. Water is getting a bit clearer but very very slowly. We are now about a week in with pumps running 24 hours with pool being maintained at SLAM levels and then some.

Any words of wisdom?

 

[Smykowski]

Keep doing what you're doing. It's working, so don't back off til it's clear.

 

[dmartin]

Thanks to all for the help so far.

Discovered a new addition that had to be fished out of 48 degree water as it was sitting perfectly on the main drain intake grate, and I could not get it to budge while on the pool deck with every pole tool I have :grrrr:

[attachment=1:1i17xtmv]20131202_190424-sm.jpg[/attachment:1i17xtmv]

As it is a indoor pool I know there is no possibility of someone other than someone living in this house that put it in there.

Although I do have all the appropriate scuba equipment including a drysuit and insulation that I have taken into far colder water I opted for the much more direct and KISS approach; put on swimsuit, in pool, retrieve big rock, out of pool, and into hot shower in 90 seconds or less. 30 minutes or so of prep time plus an hour of cleanup and then hauling my doubles in for a fill just sounded like too much work for one rock although it would have been so much warmer.

So far all my three kids have done is point fingers as it had to be someone else, but dad isn't happy and I really don't believe it was this guy

[attachment=0:1i17xtmv]20131202_190415-sm.jpg[/attachment:1i17xtmv]

Peeing in the pool is one thing and we will have that discussion when the pool is finally warm and open, but rocks especially that size are another and I will get to the 'bottom' of the guilty party(s)

On the plus side I was actually able to see that someone had 'accidentally' put a large rock on the bottom of the pool, which would not have been possible to see when I first started. The rock that wound up on the bottom of the pool was not there when we first started, after more than a week of daily brushing and vacuuming I am sure I would have noticed that large of an obstruction in the bottom of the pool plus my pool pump was not happy either with pressures all over the place which was not the case yesterday evening.

The water still a bit cloudy but improving every day.

Thanks again...