CYA out of control...among other things

Jump to latest Follow Reply
V

Vyrolan

0
Jul 1, 2014
64
Prospect Heights, IL (NW Chicago)
Hello everyone. I'm new around here having just recently given in and sold my condo in the city for a big fancy house in the burbs with a pool.

Pool specs are (need to set my sig sorry) ~36.5K gallons IG gunnite with cartridge filter.

Well to no great surprise, the previous owner did all the maintenance himself. That's resulted in me buying a brand new filter (both he had were garbage) and some new temp sensors and other misc equipment. Then for the water his efforts seemingly consisted of nothing but trichlor pucks, dichlor shocks before parties, and soda ash to keep the PH up. Consequently the CYA (and TA) is ridiculous. I estimate it to be as high as 450 or even more...I haven't yet managed to dilute the water enough to ever actually get a reading.

Does anyone know a company in the Chicago area that does RO for pools? That seems to be my only way out of this mess. Otherwise I may just wait until next spring and have water trucked in for a massive replacement. I mean it almost seems ridiculous how messed up this thing is for it to be crystal clear and looking like everything is hunky dorey.
 
Welcome to TFP!

As far as I know, RO is only available in the extreme SW. If you can make it through this season, you'll usually lose a lot of CYA over the winter.
 
Wow, if we go with CYA 450 that means FC should be
Minimum 33.75
Target 51.75
Shock 180

Numbers calculated from ChemGeek's calculations
A reasonable approximation to the above table is the following:
.... "Min FC" is 7.5% of the CYA level
.... "Target FC" is 11.5% of the CYA level
.... "Yel/Mstrd Min" is 15% of the CYA level
.... "Shock FC" is 40% of the CYA level
.... "Yel/MstrdShock" is 60% of the CYA level.
Since chlorine is more effective at lower pH, it is normally recommended to lower the pH before shocking at a high FC level, especially for yellow/mustard algae where lowering the pH to 7.2 before shocking at the above levels is best (and remember that the pH test will not be valid during shocking due to high FC levels).
Click to expand...
 
JohnT said:
If you can make it through this season, you'll usually lose a lot of CYA over the winter.
Click to expand...

Yea that would be nice but I'm kind of worried about now. I don't know much about this gunite stuff...is it as susceptible as plaster to corrosion/scaling? I don't want to get into an even bigger mess. Sometimes the CSI number on poolmath scares the **** out of me (or even shows NaN), but I suspect a lot of these things break down when numbers are this crazy.

tim5055 said:
Wow, if we go with CYA 450 that means FC should be
Minimum 33.75
Target 51.75
Shock 180
Click to expand...

I know right! FC has been under 10 for like 3 weeks and water is crystal clear. All signs point to me not being able to do the CYA test correctly but I'm fairly confident that's not true. I did a dilution today of 2 parts pool to 3 parts pure water (from RO drinking water inside) and still the black dot was long gone well before I even got up to the 100 line on the comparator. It's nuts! I need to dilute more and at least try to get a reading but also I think at this point the CYA is essentially "way too freaking much". =(
 
Vyrolan said:
I know right! FC has been under 10 for like 3 weeks and water is crystal clear. All signs point to me not being able to do the CYA test correctly but I'm fairly confident that's not true. I did a dilution today of 2 parts pool to 3 parts pure water (from RO drinking water inside) and still the black dot was long gone well before I even got up to the 100 line on the comparator. It's nuts! I need to dilute more and at least try to get a reading but also I think at this point the CYA is essentially "way too freaking much". =(
Click to expand...

No, always use one part pool water, so

Pool water......Tap or distilled water.........Multiply result by**

....1...................1................................2
....1...................2................................3
....1...................4................................5

You may not be as high as you think, but still too high


**Chart by JamesW in a 2012 post
 
tim5055 said:
No, always use one part pool water, so

Pool water......Tap or distilled water.........Multiply result by

....1...................1................................2
....1...................2................................3
....1...................4................................5

You may not be as high as you think, but still too high
Click to expand...

I don't have any great way to measure volumes accurately...so I did up to 10ml on my comparator in pool and filled to 25ml with water from our RO...so 2:3...so actual number should be 5/2=2.5 times measured result. But I couldn't accurately measure so it was still way over 100...
 
Vyrolan said:
I don't have any great way to measure volumes accurately...so I did up to 10ml on my comparator in pool and filled to 25ml with water from our RO...so 2:3...so actual number should be 5/2=2.5 times measured result. But I couldn't accurately measure so it was still way over 100...
Click to expand...
Kitchen measuring cups is what I used when mine was over 200. One cup pool water, one cup tap water mixed in a glass. Then to the first line in the CYA bottle.

If it's still too high one cup pool water, two cups tap water mixed in a glass. Then to the first line in the CYA bottle.
 
As I've been thinking more about this...maybe some water replacement to lower the CYA could be a good idea here...it would hurt me in the CH department (pool is already at 675 CH and fill water from well is even higher)...but that seems arguably better than massive CYA. Unfortunately with the cartridge filter I don't even know how to go about draining short of siphoning with a garden hose. The pool equipment pad is not in the greatest location (IMHO) so doing a huge drain at the filter with the cartridge removed is a bad idea. Any recommendations for a little transfer pump I could use to pull water out? Even better if it's one I could adapt the suction side to run a vacuum as a way to vac to waste.
 
So I can get trucks of ~6000 gallons for $300... So for $900 I could replace roughly half the water...that would probably help me a lot with CH in addition to obviously with CYA. Maybe do that and then let the over-the-winter CYA reduction and closing/opening water replacement make it completely right for next season... Hmm...really need to get a reasonable grasp on what the CYA level really is...must dilute further tonight!
 

Enjoying this content?

Support TFP with a donation.

Give Support
Vyrolan said:
So I can get trucks of ~6000 gallons for $300... So for $900 I could replace roughly half the water...that would probably help me a lot with CH in addition to obviously with CYA. Maybe do that and then let the over-the-winter CYA reduction and closing/opening water replacement make it completely right for next season... Hmm...really need to get a reasonable grasp on what the CYA level really is...must dilute further tonight!
Click to expand...
If you are going to go this route, do it all at once - Drain the pool half way then add the three trucks of water. If you do it in 3 separate operations it will not give you the 50% reduction, but a smaller % (if my math is right, with your pool each truck load would be a 16% reduction.

So, if we say your CYA is 400 for arguments sake,

3 truck loads done at once will drop you to 200

Truck loads done separately will yield you the following
Truck 1 Start 400 less 64 (16%) 336
Truck 2 Start 336 less 53 (16%) 283
Truck 3 Start 283 less 45 (16%) 238
Truck 4 Start 238 less 38 (16%) 200

Someone check my math, but it would appear to get 50% separately you need 4 trucks.

Please remember, high water tables and some other conditions may preclude you from draining too much from the pool.
 
tim5055 said:
If you are going to go this route, do it all at once - Drain the pool half way then add the three trucks of water.
Click to expand...

Oh that would definitely be my plan...just let them do it all in one go....they can apparently dump the 6000 gallons in like 10 minutes....so it could be back up in like 30 minutes....but obviously it would take me like 18 hours to get it drained that low. =(


tim5055 said:
Please remember, high water tables and some other conditions may preclude you from draining too much from the pool.
Click to expand...

Yea that was my biggest concern....draining 18000 gallons would leave my shallow end at about 6" (3.5' shallow end, 8.5' deep end)... I'm not sure if I can go that far or if it's safe or what...
 
Smykowski said:
You guys are on a well in Prospect Heights? I thought all of the suburbs, with the exception of the far north suburbs, were on municipal water.
Click to expand...

We have well for input and municipal sewer for output. Apparently all of Prospect Heights is like that...no municipal water exists. In many ways well+sewer is the best of both worlds...but the well is a negative when it comes to the pool. =(
 
Rainwater is a very viable alternative given your pool conditions.


ANY CYA above about 200 I would consider an UNMANAGEABLE pool and would make no attempt whatsoever to salvage it. Drain and refill is the only thing that makes sense,
 
duraleigh said:
ANY CYA above about 200 I would consider an UNMANAGEABLE pool and would make no attempt whatsoever to salvage it. Drain and refill is the only thing that makes sense,
Click to expand...

That makes sense...I'll probably look to do that after this weekend with family visiting. How do I know how far I can drain? I'd rather not get into a series of small drain and refills with ever-diminishing returns each time.


Also...anyone have advice for convincing the wife that we should spend ~$1000 to drain and refill half the pool when it "looks" like nothing is wrong...I try to tell her that our clear beautiful water actually has bad levels of these things that don't make it unsafe to swim but do make it a pain to maintain...but she doesn't really care about such things. =p
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply