draining water.

[another one]

This is my first posting of a question, so I'm trying to explain everything.

I need to drain some water from my pool. It's a plaster pool with a row of 3 2x2" tiles on the water line, so we keep the water level to the middle of tiles - 3 inches above the plaster.

About one inch of water is 500 gallons and the pool holds about 29,000 gallons. So if I drain it to the bottom of the tiles, it would be about 3 inches or 1500 gallons.

My water comes from a well and goes through a water softner. The water softner can treat about 1000 gallons per day, and there's a 1200 gallon holding tank that gets filled at 3 gallons per minute. So I really can't put more than about 700 gallons a day into the pool.

So with all this infomation, my question is, if I drain 12 inches of water from the pool (6000 gallons) and the water drops below the tile exposing the plaster and then fill it at 1-1/2 inches per day, so the plaster at the very top is exposed for 6 days is that bad?

And if it's not bad, could I drain even more and slowly refill it?

Thanks.

 

[Bama Rambler]

The normal concensus here is that a day or two is usually ok but six days would be too much. BUT, you have an indoor pool so that may change things. I'll let the plaster people chime in before making a statement.

 

[Guest]

Plaster does not like to be exposed, so any time without water is detrimental. Being as yours is an indoor pool, that does make a difference. I would take into consideration how much (if any) sunlight it gets, and what the temps are indoors. At any rate, I would try and limit the exposure, or wait until winter/cooler temps, if you can.

 

[another one]

Thanks for the responses and info. My TF-100 kit is scheduled to arrive on July 9th (ordered on the 1st, but got hit by the holiday). And I'm sure after 10 years of using pucks, shock, and other products from the pool store, my pool has too many bad things in it.

So after I test, if I need to remove stuff, I'll drain 2000 gallons (about 1 inch below the tile line) and fill it back to 1/2 inch above the tile line and repeat for a while. I figure I can build an excel spread sheet that gives me info on how much I've diluted the water with fresh water.

More questions to follow, I'm sure.

 

[crewchief47]

On one of the build threads, I believe from Texas, the installer used an intex style pool to start running the hose when they first put the shovels in the ground. The result was that by the time they had the pool installed, they had this temp pool already full of water and just pumped the water from the temp into the new pool. Long story short, I wonder if something similar couldn't be arranged for your needs.....

 

[another one]

On one of the build threads, I believe from Texas, the installer used an intex style pool to start running the hose when they first put the shovels in the ground. The result was that by the time they had the pool installed, they had this temp pool already full of water and just pumped the water from the temp into the new pool. Long story short, I wonder if something similar couldn't be arranged for your needs....

That's a pretty clever idea. When we filled the pool, we had a water truck come over and fill from the hydrant 2 miles away.

 

[another one]

Not sure if this is the right place to post this (should I have started a new post), but since my testing kit doesn't arrive until Friday, I thought I'd stop by the pool store today with a sample of my water, here's the results:

CYA 94
TC 0
FC 0
pH 7.8
TA 88
Total Hardness (CH?) 357

Plus other numbers
TDS 800
Saturation Idx 0.2


So if these numbers are accurate, looks like I'll be draining some water.

Question, is it safe to use the pool if I correct the other numbers?

Thanks.

 

[Bama Rambler]

I'd pour some bleach in there to get that FC up to what's recommended for that CYA and then it's fine to swim.

 

[another one]

Ok, I just spent this morning with my test kit and tested a few things:

CYA came out between 50 and 60, not the 94 the pool store said. Closer to 50 then 60. Still need to drain some, but I'm not so worried.

Question: I assume I can repour the test liquid from the tube with the black dot back into the mixing container if I over shoot it, right?

TA read 170, pool store said 88.

CH read 300, pool store said 357.

pH read 7.8, pool store said 7.8

Obviously, this is my first time with the kit, so I'm going to retest tomorrow after I add 4 jugs (182 oz) of bleach and 1 gallon of MA.

Thanks.

P.S. I've been reading this forum for about a week and I have to say the members are the most courteous and respectful I've ever read. Bravo!!

 

[duraleigh]

Trust your results on the CYA test. Yes, you can repour the solution over and over to "retake" the test. Make sure the dot is completely obscured.

If you did not wipe the dropper tip on the TA test every 2-3 drops, repeat that test and do so. When it's new, the R-0009 "jumps" off the tip from static....wiping the tip will stop that and give you a different, lower reading.

One gallon of MA is a bunch. Have you done the calculation on that?

 

[another one]

One gallon of MA is a bunch. Have you done the calculation on that?

Sorry, I should have posted that it's the weak Home Depot version - 14 or so percent, so it's 1/2 gallon of the real stuff. I didn't research MA until I looked at my jug and realized I'd been duped into buying 2 gallons for $9.59 or the weak stuff, thinking I had the normal concentration.

And I'm trying to lower my TA, so I'm trying to lower the pH to around 7.1.

Which leads to another question - I have a 8' x 8' overflow spa in the corner of the pool. Does running the spa jets have the same effect as aerating the water?

 

[frustratedpoolmom]

Which leads to another question - I have a 8' x 8' overflow spa in the corner of the pool. Does running the spa jets have the same effect as aerating the water?

Yes, if you can exchange the water fairly quickly that should help the process.

 

[another one]

Hi again, so after adding four 182 oz jugs of bleach and one gallon of 14% muraitic acid, here are the test results 24 hours later:

pH - 7.5 (maybe 7.4)
FC - 16.5
CC - < 0.5 - turned clear the instant the drop hit.
TA - 175
CH - 300
CYA - 60

But targets I set in the pool calculator to get the amount of bleach and MA were:
pH - 7.2
FC - 12

So why is the FC so high and the pH not lower?

 

[Bama Rambler]

It's possible that your pool isn't as large as you think it is. That's probably the most common thing to happen when the chem additions don't add up.

 

[another one]

I would tend to agree with you if the PH came down to 7.2 or lower, but the chlorine over shoot it's target and the pH undershot.

Estimating the pool volume is a bit of a trick. Previously I used 28,000 gallons, but when I recalced it, it came to 29,000.

Here's how I came up with 29,000. The actual dimensions are 18' 8" x 44' 8" with a spa in the corner that is 7'4" x 7'4" with 12 inch walls and 4 foot deep, but it has seats, so estimating it's volume is a challenge, so let's just ignore it for now.

Pool goes from 3' to 4' in the 8'4" of pool boarded by the spa, then the rectagular area outside the spa (18'8" x 38'4") goes from 4' to 6.5' in the center then back to 4' at the far edge.

So, if we use 5' as a average depth ofthe 18'8 x 38'4 rectangle we get 3576 cubic feet of water.
and the other rectangle, 10'4 x 8'4 and use 3'4" as depth we get 280 cubic feet.
So total cubic feet would be 3856, times 7.48 gallons per foot yields 28,842.

So with the spa, it seems 29,000 would be a good estimate.

 

[Bama Rambler]

pH adjustments aren't very accurate especially when you're trying to adjust it more than a few hundredths. Chlorine additions are usually pretty spot on, though it does take a while to narrow the target down. Keep up with how much you add and how much it moves the FC and you should be able to get a pretty good fix on the size before long.

 

[another one]

Okay, last reply in this post, but a quick question before I start draining 700 gallons per day.

My chlorine level (FC) has remained at 16.5 over night. I'm thinking this is because of 2 things, one the water is cool - about 63 degrees and two, even though the pool is opened, it was been cloudy all day yesterday. Am I correct in these assumptions?