Drain and refill plaster pool with temps in the 80s?

[entropic]

Hi all,

Been lurking the forum for the past 6 months since we bought our first house with a pool. Already learned so much. Been spending the time getting comfortable with the TF-100 test kit and how the pool reacts to changes and I'm so much more comfortable now.

Our CYA is off the charts; with 4 city:1 pool dilution extended test I get results in the 450-500 range, and have been planning to drain, refill and start over since discovering this the day we bought the place and tested that day . PoolMath is suggesting a 97% drain just for that. CH also high with 1100+. Seem easiest just to start over, and I've been waiting for March for my sewer bill to not be affected by the water refill for the next year.

2 main questions:

1. I'd love to start draining tomorrow, but it's going to be in the low 80s here in Tucson, AZ through the weekend. What I can find says to not drain when it's above 90, to avoid cracking, but would love to get TFP opinions on the temperature and if I'm relatively safe from plaster cracks.
2. I've got the 3 Bs on hand, and will grab some more acid and get some CYA and plan to add that with the sock method, but are there any other non-obvious chemicals I should have for fresh fill water? Might even have to get some calcium; my last test of the city water was showing 150.

I also plan to get in there with my consumer grade pressure washer, mostly just to get build-up on the tiles and any problem areas that are discovered, but don't think we need any kind of acid wash from what I can see.

Thanks for any advice!

 

[Jimrahbe]

John,

Welcome to TFP... a great place to find the answers to all of your draining questions...

"Most" cities will waive sewer rates, if you tell them ahead of time you want to fill a pool... I would check with your water department to confirm...

You don't want to drain and let it sit for a long period of time in the middle of the summer.. But I can't see any problem with draining and then refilling the next day..

How old is your plaster??? I ask because the water will hold loose/weak pieces of plaster in place... Using a pressure washer could cause the weak places to come off. I've had a couple of pools re-plastered.. When they do this here, they take a hammer and tap all around the pool to find the hollow sounding areas.. I was amazed at the number of weak places they found.. You could not tell when looking or swimming in the pools..

Thanks for posting,

Jim R.

 

[entropic]

Thanks for the advice, Jim! You're right in that I'm hoping to have the pool sitting for less than a day. I'm hoping to drain/clean/start to refill pretty much straight through.

How old is your plaster??? I ask because the water will hold loose/weak pieces of plaster in place... Using a pressure washer could cause the weak places to come off. I've had a couple of pools re-plastered.. When they do this here, they take a hammer and tap all around the pool to find the hollow sounding areas.. I was amazed at the number of weak places they found.. You could not tell when looking or swimming in the pools..

The previous owners re-plastered in 2014. Possibly 2015.

I'm hoping I'll be using the pressure washer pretty sparingly to be honest. The pool has minimal staining and looks good from what I can see topside. Our washer is also not exactly heavy duty; it's one of those light-duty 110v Karchers from Wal-Mart that we got to prepare for a DIY roof recoating and use most often for washing cars.

 

[Dirk]

If you're going to drain your pool completely... right before you fill:

Pump out all the yuck and all the water out of the pool you can. Then have everybody take their showers, use the toilets, washes the dishes, etc. Then go read your city's water meter and record the number. Start your fill and resist using any water (or if you have to use the toilet(s), keep track of the number of flushes). No showers. No watering the lawns, etc. Finish the fill. Go read and record the meter reading, then go to the bathroom!!

Calculate the difference between the two numbers, subtract a gallon or two for every flush you snuck in there, and voila! You'll have a very accurate number for pool water volume, which will help you with all your pool water chemistry adjustments.

Some meters are in gallons, others are in units. You'll need to know which and do the proper math...

 

[entropic]

Then go read your city's water meter and record the number. Start your fill and resist using any water (or if you have to use the toilet(s), keep track of the number of flushes). No showers. No watering the lawns, etc. Finish the fill. Go read and record the meter reading, then go to the bathroom!!

Thanks for the advice, Dirk! We were planning on doing something like this, and seeing how the pool has reacted to chemicals since October has made me think the pool is much closer to 14k-15k gallons than the 17,770 quoted by the previous owner. Beginning to think he meant 14,770.

 

[Dirk]

You'll soon know for sure!

 

[triptyx]

80's aren't ideal Entropic, and our desert climate means the plaster will dry out pretty fast and you want it to stay cool and moist. That said, keep a hose handy and while the plaster is exposed, give it a wetting with the hose every half hour or as needed to keep it looking moist. I drained successfully last year in the mid-80's with no apparent ill effects - just keep spraying the plaster. I use a lawn sprinkler in the shallow end to keep that surface nice and wet at all times since it will be taking the most sun.

Tucson water calculates sewage rates for the year based on December, January, February average. They will not waive sewer or extra usage water charges for a pool refill (I tried). If you're outside your February bill, you should be fine. If you're not, when they send your new rate in June, and November, December, Jan were lower then Dec, Jan, Feb, you should be able to appeal it and get the rate based on of the earlier time period. Should.

 

[entropic]

Tucson water calculates sewage rates for the year based on December, January, February average. They will not waive sewer or extra usage water charges for a pool refill (I tried). If you're outside your February bill, you should be fine.

Indeed, that jives with my research as well. I have confirmed that they read our meter already this week for the February usage so we should be good to go.

Thanks for the tip about the sprinkler, that's a great idea. I did plan to wet the plaster as much as we can.

 

[cfherrman]

Get removable tips for your pressure washer and start out with the fan or low pressure tips, you can always bump up the pressure tips for hard spots

 

[entropic]

And we are underway! Thanks for all the help y'all.

 

[Dirk]

Two more water filling tips! (I'm having a similar conversation in another thread.)

Take a picture of the meter readings. Very helpful. And mark your optimum water level with a piece of tape. It's actually pretty hard to tell where you should stop your fill. The mirror reflection and water refraction make it difficult to see where the water normally sits, and where "half way up the skimmer opening" actually is... Both of those indicators are much easier to determine while the pool is empty.

Do you have an auto fill system? What you're shooting for is halfway between the two extremes: between the level where your auto fill kicks in and where it stops filling. That'll be your average water volume. Looks like you have a bit of a calcium ring there. Your average water level is likely just below halfway through that ring. Deposits like that typically form above the water line, where the air gets at them and the water dries on the surface.

The accuracy of the water meter itself (typically about 1.5%), along with the accuracy of the test results (5-15% depending on the test) makes knowing exactly what your average water volume somewhat overkill. But if you're going to do a job, do it right, I say...

 

[entropic]

Thanks Dirk!

No autofill on this pool, which was a disappointment at first but now I've come to appreciate as I think it helps me understand more about what's going on.

I've actually had a lot of meter-checking experience on this house trying to track down an irrigation issue and I've been checking the meter from time to time when I do manual fills to check my own sanity and trying to understand water consumption. My phone has a ton of water meter pictures. I've got my eyeball-tuner pretty well set for filling but I might make a mark so that others know what to shoot for.

John

 

[triptyx]

Awesome! Great pool, great view, and good luck!

 

[Dirk]

Yes, I meant to mention that, too! Really great view!! Get so wrapped up in pool maintenance I sometimes forget: it's a pool! Enjoy it!!

I came up with the tape idea because I was trying to take a few inches off my pool in anticipation of the coming rain. So I was trying to keep track by looking at the skimmer opening from above. But because of refraction (and because I recently removed my calcium line), I couldn't tell where I was in relationship to the skimmer opening! Where the bottom of the opening is, and where it looks to be, are surprisingly different.

 

[entropic]

Thanks guys! With FC in the 30s/40s because of the ridiculous CYA, we haven't even been in the thing yet. I was the skim/brush poolboy for my parents when I was a teenager and didn't want another pool ever again, but we loved the house so took the plunge.

Reading this site and forum has really made me excited for everything that it can be and given me more confidence that I can figure out how to take care of it with enough time and testing.

 

[Dirk]

Finding TFP turned my pool around. Fired the pool guy and figure I spend maybe 30 minutes a week on maintenance. And my pool and pool water are way better off. Plus all the maintenance expenses I'm now saving! It's really quite easy to do yourself, and nobody but you is going to do as good a job (it's not their pool, or their eyes/skin/kids/health, etc).

I once did a rough calc: between pool guy labor, his chemical charges and the projected costs of repairing/replacing the damage that his incompetence would necessitate... in my lifetime (about 30 more years, if I'm lucky) I'll save over $55,000. Yep, three zeros there...

 

[triptyx]

Bear in mind that as long as FC is below shock level for your CYA, it's perfectly safe to swim. CYA buffers (locks up) the chlorine, which is why you get algae when your FC level is below the correct level for your CYA - if it was a dangerous level of chlorine, the algae wouldn't be able to live in it.

 

[entropic]

Fired the pool guy and figure I spend maybe 30 minutes a week on maintenance. And my pool and pool water are way better off.

Yeah, and I can very much see how that could happen! I get the sense that for many people that as long as the water's not green or black it must be perfect but I've got higher standards than that.

Bear in mind that as long as FC is below shock level for your CYA, it's perfectly safe to swim.

It's a good point you make, triptyx. My apprehension is probably unnecessary, but was based a bit on how bleached the purportedly new pool toys were and how itchy the water seemed to make me when I'd put my arm in there to connect the cleaner or take a water sample.

But I'm a believer in the chemistry for sure as I've added chlorine to keep it in the right range given the CYA and the water stayed clear and reacted to sun, rain and temp changes in a predictable way.

Luckily the water's been too cold to feel like jumping in anyway, but as you know it might just turn into swimming weather in a matter of weeks!

 

[entropic]

You'll soon know for sure!

Indeed! What I was told was a 18k gallon pool, and thought was more like 15k, measured out at 13,150 gallons on the meter. We had some light sprinkling yesterday (I was thankful for the clouds and temperature drop) but I don't think it added much water, probably made up for splashing-out we did trying to keep the plaster wet and very minimal water use in the house. But does make it a bit of an imperfect test.

My faucet and fixture tyranny is now over and my permanent roommate can once again shower and do laundry.

My new results after a few hours of the pump circulating things, just added a little more bleach and will check again this afternoon:

FC: 3.75 (doing extended 20mL tests for this)
CC: 0
TC: 3.75
pH: 7.2
CH: 225
TA: 130
CYA: 60. Maybe 50.
Salt: 200 (I want to go SWG later, this is mostly just for completeness and curiosity)

Thanks for all the help. Everything is looking pretty good.

 

[Dirk]

Wow, your pool went on a diet and lost 5000 gallons? She shoulda eat, mangia, mangia, shes'a lookin' kinda thin!!

Did you add CYA? There wouldn't be any CYA in a fresh fill, it's something you add to your pool.

Are you planning to take care of the water yourself? Have you read Pool School, and learned about Pool Math? I'll leave the chem recommendations to the experts here, but your numbers look a little off for a plaster pool (but easily correctable), most fill water is.

If you are considering doing you're own care, now's the time, before you let any pool "pros" near it, like maintenance guys or pool stores...