Trying to get the CYA under control.

[LordBob]

Your CYA is out of testable range. So by diluting the pool water 50/50 with tap water, you can hopefully get the test within the range of your test kit. But you have to multiply the test result by 2 because only half the water is pool water. Tap water has zero CYA.

Okay so by multiplying it by 2 if it is in the testable range, it gives me what my actual CYA is in the pool now. which is 90x2=180. My thought was if I dilute the pool water by 50% and it came in within the range I am looking for that would be what I would want to dilute the pool by, but I understand now thanks.

 

[DeanP66]

You really want to get that CYA down to around 50. Even 60 would be ok. If your CYA is 180, you need to drain almost 75% of the water to get you down to 50.

 

[LordBob]

Another question, this is what the health department requires my test kit to do:

The pool operator shall maintain a test kit for measuring the disinfectant residual, pH, and, if used, cyanuric acid concentration at the public pool. This test kit shall be available for use by the pool operator and the enforcing agent at all times the public pool is in use. The chlorine or bromine test kit shall be the diethyl-p-phenylenediamine (DPD) type or otherwise be capable of testing free-halogen residual. Chlorine test kits shall be capable of testing for free chlorine and total chlorine.

What is residual Disinfectant, and is the TF-100 kit a diethyl-p-phenylenediamine (DPD) type or otherwise be capable of testing free-halogen residual?

 

[Teald024]

Hello and Welcome to TFP!!
The TF-100 kit can and does meet those requirements. In fact it uses industry standard Taylor brand reagents. You can’t find a better, more accurate test kit.

residual Disinfectant is the measured FC.
The TF-100 kit FC/CC test is technically FAS-DPD, but it is very suitable to give the results needed. It measures FC and CC separate and can be added to get TC

 

[LordBob]

Hey guys, it's me again with more questions. here's the update on where I'm at, I have drained about 70% of the pool, and am in the process of refilling the pool. I put 2 gallons of chlorine in while it is filling, and as soon as it is filled I will post the test results for some help with where to go with the chemicals.

When the pool is filled and I'm getting ready to fire the pump and filter back up.
Should I break down the filter and clean it to start fresh?
Do I need to prime the lines, and if so where do I find how to do that?
What is the optimum CYA level to get the best use of the chlorine?
Is there a place I can find these answers, or do I just keep asking questions?

Thanks again guys, you have been so very helpful in this massive learning process.

 

[DeanP66]

Just keep asking questions. There's always someone willing to help you out. I'll try to answer a couple of them. How long has it been since you last cleaned the filter, or even backwashed it? If it's been a while, it might be a good idea to do it now while you wait for the water to fill back up. Take it apart and hose off all the grids, and then re-install everything so it's ready for the DE when you get your pump turned on. For the DE, it's best to mix the powder in a bucket with water and stir it before adding it directly to the skimmer slowly. It will coat the grids evenly this way.

When you're ready to turn on the equipment, you'll have to prime the pump first. Make sure the water level is above the skimmer line so the pump doesn't draw air when you turn it on. To prime the pump, simply open the pump lid and fill it with water from a bucket fast. Close the lid, lock it down, and start the pump. Make sure you have your filter air bleeder valve open when you do, so the air will escape out of the filter. Once water starts to come out of the air valve, close it all the way.

The optimum CYA really depends on your conditions. Do you get a lot of organics falling in the water? Leaves, debris? What's the weather like where you are? If it's generally very hot during the summer, I'd go with a CYA of 50. If you go with 30, you probably won't make it through the day without your FC dropping below your required minimum. With CYA of 30, you FC only needs to be in the 4-6 range and never below 2. However, the sun will burn it off quicker than if you keep your CYA at 50. I'm in San Jose and it's very hot here. I keep my CYA at 50 year round. Although I have to maintain FC of 6-8 PPM and never below 4, the chlorine seems to burn off more slowly. This way it gives me a little leeway in case I can't get to it that day or if something comes up. I wouldn't go above 50 though.

There's general rules in pool school and a lot of those other articles, but the best way to learn this stuff is to monitor your pool closely, at least at first, until you get a feel for how everything works. It will become 2nd nature after a while as long as you maintain the FC/CYA relationship. That's the key to TFPC in my opinion. Just about everything else can be fixed quite easily if you maintain the proper FC to CYA in your pool. That's why liquid chlorine is so important. Once you get your CYA to where you want it, it won't go any higher without you adding any of those solid forms of chlorine. (tablets, powdered shocks, granules)

 

[LordBob]

I back washed the filter right before the health department shut down the pool, about 3 weeks ago. We just got the pool totally refurbished last summer, and the guy that usually does the pool said they told him the filter doesn't need to be cleaned (as in opened up and the grids washed off) just to backwash it, but that doesn't sound right to me, and he is known to do things (pardon the expression) half assed. Everything I have read says to wash the grids down at least at the beginning of the season. I am familiar with how to clean the filter and put in the DE so totally comfortable with doing that.

My assumption is when you say open the pump up, you mean where the debris basket is?

There is a lot of organic material that get's in the pool, and it is a Mobile Home Community pool so it gets a lot of use too, so I'm thinking around 50 would be best.

Previous to this mess, we exclusively used the granular chlorine, and the 3" tabs in a chlorine dispenser that is built-in the piping (not sure what it's called, but I have seen the name in my reading). I will not be using either from now on. I have looked for tablets that don't have stabilizer in them, but as yet have not found any.

 

[DeanP66]

Yes, open up the pump lid so you can expose the basket. Clean the basket while you're at it as well. Then load it up with water and close it up quickly before all the water gets sucked back down the pipes.

The filter should be broken down and fully cleaned at least once a year. Regular backwashes are fine the rest of the time. Might be a good idea to fully clean it if you've got the time. That way you start fresh. Just remember you can't add the DE back in until your pool is filled up enough so you can start the pump.

 

[Teald024]

Is there a place I can find these answers, or do I just keep asking questions?

Thanks again guys, you have been so very helpful in this massive learning process.

I suggest you read Pool School - ABCs of Pool Water Chemistry and also read the entire Trouble Free Pool School book. The book is not too long and covers the basics of what we teach here at TFP. Use PoolMath to help you calculate the amount of chemicals you need to use.

I would also recommend the Pool Math app. For a low yearly subscription, you can use it to log the test readings and track chemical usage. This will be a great help when the the health dept comes knocking looking for logs.
Above all, after you read through these, ask as many questions as needed. There is also a search box at the top right of each page. It will search all of the forum posts.



There are only a few kinds of solid chlorine. Each has it's own disadvantagees.
Dichlor powder - adds chlorine and CYA at about 1:1 ratio
Trichlor tabs - adds chlorine and CYA at about 10:6 ratio
Cal Hypo tabs - adds chlorine and CH at about 10:7 ratio (calcium hypochlorite and calcium hardness)

Cal Hypo is the only one that doesn't have stabilizer (CYA) but the CH level can get very high and cause scaling if not controlled. The best way is through liquid chlorine or a SWG. Since this is a public pool, you may want to find an automated type system to add chlorine to the pool.

 

[santacruzpool]

I have looked for tablets that don't have stabilizer in them, but as yet have not found any.

You will find tablets with CYA or Calcium Chloride. One raises CYA like you have seen, the other raises CH up. At one point you posted that you had 600ppm CH in your water which is a bit high, but your drain and refill should have solved that problem.

You will want to get liquid shock and/or liquid chlorine (aka bleach). The liquid shock often sold at pool stores, Walmart, and many big box stores will generally have a higher % of sodium hypochlorite than plain household bleach. However, bleach in some cases is cheaper. You don't have a huge pool, so you may find you will need around gallon to a 1-1/2 gallons of 6-8% bleach per day - or just under a gallon of 12% liquid shock. Depending on price, and your chlorinating needs you can do the math to figure out which version is cheaper for you locally.

I found Safeway bleach to be my best bet locally - but we don't have a lot of options.

 

[santacruzpool]

Dave already covered much of what I posted - and I second the idea of a SWCG - they are awesome!

 

[26venus]

With a CH of 600 prior to your 70% drain you should be left with an approximate CH of 180. Assuming you still have an abundance of cal-hypo I would recommend using enough of it to sanitize while bringing up your CH up to the recommended level. You want to ensure that the new plaster is protected

 

[LordBob]

Cal Hypo is the only one that doesn't have stabilizer (CYA) but the CH level can get very high

Well, we already have very hard water here, so looks like Liquid Chlorine is my only option, was just hoping to find a way to supplement that to prevent having to test multiple times a day.

- - - Updated - - -

Dave already covered much of what I posted - and I second the idea of a SWCG - they are awesome!

Well, I'm at the mercy of the corporate office that owns the park, so I'm pretty sure they won't want to put the money out for any type of automated system.

- - - Updated - - -

With a CH of 600 prior to your 70% drain you should be left with an approximate CH of 180. Assuming you still have an abundance of cal-hypo I would recommend using enough of it to sanitize while bringing up your CH up to the recommended level. You want to ensure that the new plaster is protected

I'm pretty sure the CH is so high mainly because of the hardness of the water in this area, but we'll see after the fill.

 

[DeanP66]

With a CH of 600 prior to your 70% drain you should be left with an approximate CH of 180. Assuming you still have an abundance of cal-hypo I would recommend using enough of it to sanitize while bringing up your CH up to the recommended level. You want to ensure that the new plaster is protected

His new CH will really depend on what the CH of his fill water is. To get down to CH 180, he would have to be refilling with water with 0 CH. More than likely, it's probably anywhere from 100 to 250. At 250, his 70% drain and refill would drop his CH from 600 down to 350. At 100, it would drop his CH level from 600 down to 250.

- - - Updated - - -

LordBob, run all the tests once have finished refilling your pool. That will give us a much more accurate view of where to go from here.

 

[LordBob]

LordBob, run all the tests once have finished refilling your pool. That will give us a much more accurate view of where to go from here.

I will, I'm not expecting the CH to go down much if any.

 

[DeanP66]

Test the pH, TA, and CH of your fill water. My CH here in San Jose is around 300. I bet yours is somewhere around there. I did a full drain and refill last March ('17) because of super high CYA (200) and CH (1000+). After the refill, the CH settled in at 300. It's since gone up to around 500 with the top ups, but I've since discovered that I have a faucet outlet that comes from my water softener. So now, I only top up with soft water, which when tested comes out at 20 PPM CH.

 

[Teald024]

so looks like Liquid Chlorine is my only option, was just hoping to find a way to supplement that to prevent having to test multiple times a day.

The use of liquid chlorine doesn’t require more frequent testing in itself. The frequency of testing should be daily or as mandated by your local health department.

 

[LordBob]

Okay The pool is about 6" (which is aprox 3,000 gal.) from being filled, but because of water restrictions in The city I live in, in Southern California I have to wait till Friday to finish filling. I took a water sample and tested it just to see where I'm at. They are as follows.

Ph: 8.2 Pretty high, but nothing some Muriatic Acid won't take care of.
FC: 4.5
CC: 1.0
CH: 300 it did go down, that makes me happy LOL
TA: 140 not sure if this is good or bad, I haven't read up on this one yet.
CYA: 30 a bit low, but we still have some granular chlorine I think some one said it was 1:1 I guess there would be etter ways to get it where I need it though.

it looks like things are getting better a little fine tuning and we should be up and running again, any suggestions would be greatly appreciated... as long as it's not that I have to partially drain the pool again LOL.

Another thing I have noticed that when I do some of the tests after they sit fir a couple minutes the color changes (example the FC, CC tests) I'll get it clear then write down the number read the next step pick up the tube and it's slightly pink again taking 1 or 2 drops more to turn it clear again. My assumption is that I need to let the tests sit for a little bit to let everything settle before doing the math.

 

[mknauss]

Can you circulate the water you have? If not, keep the FC up and use a brush to move it around until you can get your pump operating.

Dichlor is close to 1:1 chlorine/CYA. So use Effects of Adding Chemicals in Poolmath to see what you add. Shoot for a CYA of 40. But be sure the water you have is really well circulated and test CYA again before you add more CYA via dichlor.

 

[LordBob]

Can you circulate the water you have?

Yes, I just shut the valve to the skimmer and just circulate it through the main drains.