Chemical recommendations (Newbie)

[Autonoz]

Hello to all. New here,but have done a lot of reading and have asked a couple of questions on other threads. It was requested I start my own thread with my specific parameters. I live in Arizona and temps have been in the high 100's. 17000 gallon diving pool. I have a pool guy who comes once a week and chlorinates with two floating tablet holders. It was one until the CYA levels were high. Only owned this house with pool for about 7 months and this is my first pool. My plan is to stop service and take over the pool on my own. Here are my readings with a Taylor testing kit 2006. Taken at 1000 with water temp around 84 degrees.
FC 13.2
TC .4
TA 130
PH 7.2
CH 610
CYA 200 with diluted test. That is the x2 number
I put these numbers in the pool calculator for FC and CYA and it gave the following suggestions; Add 98 oz of 6% bleach to raise FC and drain 86% of water to lower CYA.
Not going to drain pool until after summer, but want to switch to liquid bleach.
So my easy questions are;
1 Do I pull the tablets and add the bleach and only use bleach to maintain FC?
2 of course continue to add fresh water as needed and hope CYA starts to drop a little at a time if no tablets are in the water?
3 Finish my final month with pool guy using chlorine and tell him I know longer want tablets? Or just get rid of him? ( he is aware my CYA levels are high and doubled tabs to keep chlorine up, but continues to increase CYA)
He also quoted 435.00 to drain pool and acid wash pool at end of season. Is this reasonable?
Sorry so long. Please add any comments you feel are necessary.

 

[dkimble]

He is aware of the super high CYA and his solution is to double the amount being out in...

I would switch to bleach and forget the tablets. You have a good kit, and the resources here. I would loose the pool guy if it were me.

I have no idea about the drain and acid wash, so I am not sure if that is something you would need or not.

Good Luck!

 

[Richard320]

I started in pretty much the same nopat and draining was completely out of the question lest I end up paying huge fines and having a water restrictor placed on my meter at my expense.

The longer you leave the pucks in, the higher the CYA is going to get. You're already in a deep hole. You can stop digging any time now. Pull the pucks and fire the pool guy. He created the mess and he's making it worse.

You pretty much have no choice but to switch to bleach. Any of the reasonably-priced alternatives will load your pool with even more CH and CYA.

CYA will only drop noticeable amounts by water replacement. If you have a lawn, shut off the sprinklers and water with pool water, then use the irrigation water to refill the pool. That's a slow but painless way to do it.

You will have to maintain a minimum of 15 FC and target something closer to 20. Only testing will reveal your daily losses. Note that with that high FC level, your pH readings will always be suspect.

Having been there and done that, I can tell you right now that you'll be happier and pool maintenance will be easier if you lower the CYA. Even taking it down to 100 CYA will be a huge improvement. At least then you can trust your pH readings. But since you're determined to work with it, you may as well order some extra FAS-DPD reagents because you will be using them every single day to test the chlorine. Also, learn to do the FC and CH tests using the 10 ml sample size.

 

[Topher55]

I was in your shoes when I first bought my house, cya through the roof in the middle of the swim season. At the time I didn't want the pool out of commission while I drained 80% to get the cya down. Pool wound up down due to algae longer than it would have taken to drain and fill. My advice is to bite the bullet and drain to get cya to a manageable level. That's what I should have done, a 200+ cya isn't manageable.

To answer some questions, yes no more tablets. bleach/liquid chlorine only

Just adding fill water won't bring your cya down much. it could literally take a few years to get it down if all you have is splashout. The only way cya leaves the pool is splashout/draining. It doesn't break down or evaporate with the water.

And no clue if $435 is good... I used a $50 sump pump from harbor freight. Pretty easy just estimate how far you want it down and let the pump run. Just research before you drain you have to be careful with vinyl and other items. I have a plaster pool in solid rock so no issues here. But yours might be different.

 

[Autonoz]

Purchased 10% liquid chlorine today and am pulling the tablets. I know the only way to get my CYA down is to drain and refill. My only concern is with the high heat and a plaster pool, not sure about draining at this time. I suppose I could drain it down 3/4 and refill. Those with experience and the true knowledge, should I be draining with this high heat?

 

[Autonoz]

Anybody in here from Arizona that can recommend or deter me from draining my pool half way during our hot summer. I am trying to keep my FC at 20 since my CYA is over 200. without leaving pucks in it is a challenge. My PH is now 7.4 since I pulled the pucks. My TA is 125 and my CH is 600. We have had monsoons every night and I wake up to a pool full of dirt and leaves and sticks. Constantly cleaning. My FC fluctuates 6PPM in a twentyfour hour period and I believe it is from all the debri from the storms. My filter pressure has increased by 5 PSI and I will be cleaning my cartridges tomorrow. I am sure they are filthy after these storms. Can that be what is also eating the chlorine. I imagine the hot sun, debri from storms and dirty filters is causing my chlorine useage. Is that fair to say? My pool is clear and no signs of algae.

 

[JoyfulNoise]

You should NOT drain a pool this time of year. The heat is way too high and you can easily cause shrinkage cracks as the plaster dries out. You really should not drain until the air temps drop below 85F consistently which is basically late October.

If you really want to get you CYA down and you're willing to pay a premium for it, look into RO filtration. It's not the greatest solution (costs more than a drain & refill) but it can be done anytime.

 

[Autonoz]

You should NOT drain a pool this time of year. The heat is way too high and you can easily cause shrinkage cracks as the plaster dries out. You really should not drain until the air temps drop below 85F consistently which is basically late October.

If you really want to get you CYA down and you're willing to pay a premium for it, look into RO filtration. It's not the greatest solution (costs more than a drain & refill) but it can be done anytime.

So the path I'm going is the correct one? Keep the pool clean, my chlorine levels to match the CYA levels and try to make it through the summer? Can you answer my concern about the storm debris? Does the storm debris cause a high usage of chlorine? Is this the possible reason for my high consumption in a 24 hour period? My overnight was 2PPM with dirty filters.

 

[Richard320]

Yes, a bunch of organic debris can rob chlorine. It doesn't differentiate between algae and other organics.

 

[JoyfulNoise]

So the path I'm going is the correct one? Keep the pool clean, my chlorine levels to match the CYA levels and try to make it through the summer? Can you answer my concern about the storm debris? Does the storm debris cause a high usage of chlorine? Is this the possible reason for my high consumption in a 24 hour period? My overnight was 2PPM with dirty filters.

Storm debris does not usually cause excess FC demand, that's a misconception promoted by pool stores so that they can sell more chemicals during the "dreaded" monsoon season ("Monsoon-proof you're pool!! Make sure you stock up on shock, algaecide, blah, blah, blah..."). Unless you get a ton of dirt and farm run-off into your pool, the excess chlorine demand is minimal as long as you keep the pool clean and don't let it decompose. Using disposable hair nets in the skimmer basket to capture fine & coarse debris helps to keep the pump and cartridge filter clean and minimizes the frequency of cartridge cleaning.

Based on what you have posted, you should do an overnight chlorine loss test to make sure you don't have the beginnings of an algae bloom. If you pass OCLT, then we'll see what other options we have.

 

[Autonoz]

Based on what you have posted, you should do an overnight chlorine loss test to make sure you don't have the beginnings of an algae bloom. If you pass OCLT, then we'll see what other options we have.

I performed the OCLT last night and had a 2 PPM loss. I would be more concerned if my pool had no extra debris from the storm, my filters were freshly cleaned, and my pool was not crystal clear without any signs of algae. But I am a rock and your stating if I fail the OCLT I should SLAM. That is a heck of a lot of chlorine with a CYA of 240.

- - - Updated - - -

Yes, a bunch of organic debris can rob chlorine. It doesn't differentiate between algae and other organics.

Thank you for you response. I hope this is the case.

 

[JoyfulNoise]

Then get your pool and filters clean and repeat the OCLT.

In general, storms don't make any difference to a pool. We've had a week straight of afternoon/evening rains here in Tucson and I've gotten up everyday to put the robot in the pool and clean out all the junk that blew in overnight. My FC holds just fine with no loss.

 

[Autonoz]

Then get your pool and filters clean and repeat the OCLT.

In general, storms don't make any difference to a pool. We've had a week straight of afternoon/evening rains here in Tucson and I've gotten up everyday to put the robot in the pool and clean out all the junk that blew in overnight. My FC holds just fine with no loss.

I appreciate your responses and I am not doubting you. Here is my game plan. I am going to make sure my pool is brushed and clean. I am going to put new filters in since I was going to do this anyways. I will then do an overnight FC test. If I do not pass I will slam. The calculator is saying add 12 gallons of 10%. Is this safe?

 

[JoyfulNoise]

No, don't add that much bleach. You can't test that high. Let me consult with some other experts on this. Hold tight.

 

[Autonoz]

No, don't add that much bleach. You can't test that high. Let me consult with some other experts on this. Hold tight.

Ok, holding off until I hear back from you. Thanks

 

[Leebo]

Autonoz,

For starters, welcome to TFP!

By far your best bet sounds like Reverse Osmosis. It’ll address both your CYA issue and the CH issue you’re heading into. It may not be cheap but it will be the best long term solution IMHO.

 

[Autonoz]

Autonoz,

For starters, welcome to TFP!

By far your best bet sounds like Reverse Osmosis. It’ll address both your CYA issue and the CH issue you’re heading into. It may not be cheap but it will be the best long term solution IMHO.

Unfortunately I have not found anybody doing this. There is a company in Tucson, but their machine is down and won't be repaired for a few months. If anybody else does it, they are not advertising for it, or I'm just not looking in the right place.

 

[JoyfulNoise]

Unfortunately I have not found anybody doing this. There is a company in Tucson, but their machine is down and won't be repaired for a few months. If anybody else does it, they are not advertising for it, or I'm just not looking in the right place.

Did you check up in Phoenix?

You really need to RO the water if you can. Draining a pool is just too dangerous to plaster. Your other option would be to run a slow submersible pump in your deep end and add water from your spigot in the shallow end and then try to match the discharge and input flow rates to keep the water level. You want to do this without the pool pump running so as to not mix the water. It will take a long time but it might work. The only other option would be a series of partial 3" drains over the course of a week to see of that lowers the CYA enough. You use more water with partial drains than one big drain but you can't do a big drain so your stuck with partials.

Are you near a municipal fire hydrant at all? In some areas you can apply for a permit from the city to use a fire hydrant to fill a pool. They give you a portable meter that you have to hook up to the hydrant and you pay for the water you use. If this is possible in your area, then you could quickly drain your pool while keeping the plaster wet with a garden hose and then refill quickly from the hydrant. A fire hose can fill a pool in a matter of a few hours rather than days with a typical household spigot. Just don't aim the fire hose spray at close range to the plaster or the force of the water could damage the plaster.

 

[JamesW]

Here's a way it can be done.

Rig up a way to lose water at a slow but controlled rate. For example, remove filter drain plug, screw in a threaded reducer down to 3/4" threaded, screw in a garden hose adaptor and run the garden hose to wherever you want to waste the water.

Get the oversize tarp or plastic drop cloth and put it on the pool with about 2 to 3 foot overlap and secure with something like water bags. Just enough to keep it from blowing in the wind. The excess tarp slack goes on the water.

With the pump on, water will begin going out of the hose to waste.

Then, begin filling with a garden hose at the same rate as the water is being lost. Watch water level and adjust fill as needed to maintain the water level.

The tarp will slowly lower into the water. Once the water exchange is complete, pull out the tarp.

The size of the tarp needs to be about pool size plus 6 feet plus 2x the number of feet desired to be drained.

For example, a 20 x 40 pool where you want to drain 3.5 feet would need a tarp 33 x 53.

The tarp should not be secured in a way that would allow tension to develop in the tarp. The tarp should remain loose and not support any water weight.

 

[JamesW]

You really don’t even need the tarp. It’s just more efficient.

For example, going from 200 CYA to 80 CYA, you need to exchange about 60 % of the water for a total water demand of about 10,200 gallons.

However, if you filled and drained at the same rate without a tarp, the water would be continuously diluted. The total water demand would be about 88%, or 14,960 gallons.

The difference in water demand is 4,760 gallons. If your water is not expensive, that might be the best solution. No need to buy a tarp or expend a lot of effort.