High CH and CYA at our 'new to us' pool-help!

[Summoner12]

My brother in law/sister in law have just started renting a home that has a pool. Collectively we have no personal experience operating/maintaining a pool. I am a mechanic, so I am pretty technical. We figured out how the pool functions pretty quickly. I am sort of spear heading the 'get rid of the pool guy, it can't be that hard to maintain this pool' idea. I seem to be getting them on board the more we research. In the first couple of weeks I convinced them to get The Pool Cleaner and a venturi surface skimmer that operates using the return water jets. Adding these two items has made the pool pretty much spotless, and they have trees all the way around the pool dumping leaves continuously.

Here is a bit about the pool: the pool/spa seems to be fairly old, but everything works and equipment is fairly new. The pool has a Hayward 60DE filter, a Pentair variable speed pump, a Hayward heater (not sure on size). The plumbing... Bits of it have been updated around the equipment but the stuff coming up out of the ground looks original. It seems that there once was a dedicated vacuum connection on one side of the pool, but I am pretty sure has been plugged at the equipment pad. I am not really sure why. The skimmer has a single hole in it. When we hooked up the rover to it, we did not have any issue with water being pulled from the single floor drain. I am not sure of it, but maybe there is already a diverter installed on the skimmer (any idea how to determine if there is one)? The equipment pad has two return lines and two suction lines. One return is to the spa's four jets, the other is the pool, which also has a T on it that returns some water to the spa (there is a small waterfall). There are three jets on the wall in the shallow end, farthest from the skimmer. The suction options are from the skimmer/floor drain of the pool (but floor doesn't seem to work) and then the spa has two floor drains. We think the pool is 18,000 gallons... it's an odd shape and hard to calculate.

Typical operation is to have the plumbing set to: suck from pool (with rover plugged in to the skimmer) and return to the pool with our newly installed skimmer on the return jet in the far corner of the pool. We plugged two of the jets to get more flow at the return jet with the skimmer attached. The pool is mostly used on the weekends. Since it's gotten cooler, my brother in law fires up the heater and brings the pool to 90* on Fridays.

So now that we've figured out the cleaning aspect of the pool care, we broke out the test kit they purchased (Taylor K-2006). Here is what we got:

FC 2.4
CC .6
PH 7.4
TA 150
CH 800
CYA >100 (it was 'off the chart' since the test vial doesn't give a range above 100)

I pumped these numbers into the calculator on this site and it said I'd need to drain 63% of the pool water to get my CYA down to 50 (guessing that the reading was 130).

So far our experience with the pool has been that we itch like CRAZY after we get out. This itching continues for a couple of days and lotion is needed to calm the skin. I am assuming this has something to do with the CH and CYA?

We intend to drain the pool down maybe 50%, does this seem like a good starting point? or should we start fresh? I did some research on the cost of refilling. According to the city rate, it'd only be about $35 to fully drain and refill 18,000g.

I wanted to get some veteran feedback before we do this. I am assuming we will need to treat the pool as a 'new pool'? I need to further research that process.

Thanks in advance!
Kevin

 

[kimkats]

HI! We are SO glad you found us! Good job getting the test kit! WONDERFUL first step!

I will not speak of the equipment as that is not my strong area.

The water I can help you with! We will work on CYA and CH to start with.

You are so right in that you NEED to drain down your water to get that CYA and CH under control.

I see that you are in CA. How are your water restrictions where you are at?

If you can drain and refill 50% that would be the way to go. You MIGHT need to do it again depending on how high your CYA really is. It could be higher than you think.

How are you adding FC to your pool now?

When you get it drained and refilled let the pump run overnight to mix it real good. Run a full set of tests and we will go from there.

I would NOT drain the pool dry as there is always the risk of the pool popping out or the plaster getting too dry.....or something bad

I will be waiting to hear back from you.

Kim

 

[Swampwoman]

Welcome, summoner.

Can you please add pool surface and equipment details to your signature?

If your pool is vinyl line, you do not want to drain further than 1 foot in SHALLOW end...or risk floating I wrinkling the liner.
If fiberglass, there is a risk of popping, so again, partial drain s better.
For gunnite/plaster pools when draining trick is to keep plaster moist by spraying if hot so it doesn't dry out.

Drainly safely also depends on water table, so safest bet is always a partial drain or series of partial drains if required -- especially if this is a rental pool in that landlord may have specific preferences in terms of risk tolerance

Does the rental agreement specify the pool service? If so, you'd need to get landlord on board with TFP methods, I think.

Lastly, at such a high cya level, your FC isn't adequately sanitizing the water -- the relationship between FC:cya is what determines sanitization. Please read the FC:cya ratios in my signature link.

My bet is that the skin irritation is from low-level non-sanitization, eg. Something like Pseudomonas (also called hot tub itch...but not exclusive to hot tubs...this bacteria grows in improperly sanitized pools too, especially at higher temperatures) or harsh ccs that have not been oxidized via higher FC levels.

So if you go back in the pool before you change the water, bring your FC up to just under slam level to see if that makes a difference

 

[Summoner12]

I am pretty sure the pool Surface is plaster. The texture is a bit rough.

I will edit my signature, thanks.

I called the city about their water rate to see if there are tiered rates. I said 'for example, I need to refill my pool'. She didn't bat an eye and just said the rate is simply per unit used (100 cubic feet). So I am guessing it's not a big deal.

What at are the risks with the plaster being damaged? The pool hardly gets direct sunlight for very long during the day. The temperature is very cool right now.

My my hope is to get the floor drain working so we can use the pool pump to drain the pool. This should go much faster than using a Danner mag 5 I have laying around. My other option is to drain the spa down a couple of times. But this would be a slow process ask well.

This is the skimmer we added. Works pretty well.


Once the pool is drained and refilled. Is stabilizer a one time deal, or do you need to add more over time, like chlorine?

 

[kimkats]

It is mostly a not a many time deal. You will have to add it when you fill the pool. With a lot of rain and overflow you might have to add some more every once in a while.

IF you use chlorine tablets or powder shock you will be adding CYA for each tablet or bag..........that is why we use liquid chlorine/bleach for our daily FC.

Kim

 

[Summoner12]

Here is an update:

My brother in law drained the pool down 36" on Tuesday. He figures this is 60% of the volume. He read that the taylor kit CYA test can be done diluted 50% with distilled water to get readings higher than the 100ppm mark. So he did the diluted test after the drain/refill/circulate for 18 hours. His reading: 150ppm (75ppm diluted). This is AFTER a 60% drain down. The CYA wasn't just 'off the chart', it was WAAAYY off the chart. When I did the test the water was chunky... like floating bits in the water, not just cloudy.

​

Because he has his family in from out of town, he decided to spike the chlorine to make it safe to swim and will continue the drain/refill procedure. He has also removed the chlorine blocks which are the main source of his issues.

I was talking to a coworker and he said plaster pools should be smooth. Well this pool isn't smooth. It feels like 40 grit sand paper. Is this a type of surface or is the plaster just F'd? Maybe I can get a photo of it when he drains the water down again. But my feet feel like I was getting a pedicure and the technician went a little overboard removing my calluses. My niece likes to arm walk around the edge of the pool so we have to hold on to the wall and use our feet to 'stand' on the edges of the pool as a safe guard (she's only 3 and can't swim). So it's not 'normal' pool activity that causes our feet to hurt.

 

[duraleigh]

Sounds like the pool you are speaking of has been badly neglected for a very long time. The CYA needs to be at a manageable 50 ppm or so.

The harshness of the surface you are describing sounds like Calcium scale. High CH and high pH over a long period of time usually causes that condition.

The fix is your BIL need to manage his pool by learning and understanding why you keep certain parameters withing certain guidelines. Suggest to him he read "The ABC's of Pool Water Chemistry" up in Pool School.

 

[Summoner12]

Sounds like the pool you are speaking of has been badly neglected for a very long time. The CYA needs to be at a manageable 50 ppm or so.

The harshness of the surface you are describing sounds like Calcium scale. High CH and high pH over a long period of time usually causes that condition.

The fix is your BIL need to manage his pool by learning and understanding why you keep certain parameters withing certain guidelines. Suggest to him he read "The ABC's of Pool Water Chemistry" up in Pool School.

The BIL is now very aware of the pool chem. He's been reading this site as well.

Apparently the pool guys aren't FULLY to blame for the water condition. I guess they told the realtor/property manager the pool needed to be drained and she refused. But what gets me is, why not tell to new tenent who is paying you and swimming in the junk water? I still don't like the pool guys... If they were testing this water why wouldn't they tell my BIL what the deal with the pool is and stop using the darn chlorine blocks?

Either way, the pool is getting much better care than it was and will be far more enjoyable now. My sister in law texted me today saying the water feels much better, even with the CYA at 150ppm, at least the FC is much higher than it was.

Is there any fix to the plaster besides replacing it?

 

[duraleigh]

First you have you assume that's Calcium scale on that pool surface. It most likely is, but it is still an assumption.

Next, you need to find out the CH of your fill water to see if a apartial drain is helpful.

Then, over a LONG, LONG period of time you can monitor and lower your pH down to 7.0 and make sure it stays EXACTLY there. This will "disolve" the calcium scale buildup. It will take at least months and perhaps longer.

No drain acid wash and a drained pool are also possible but quite expensive if it's not your pool.

 

[Summoner12]

Just an update. We did a full drain and refill on the Nov. 25th. We got all of the parameters within range and the water feels great!

Thanks for the help guys! I will upload some photos I took during the process.

 

[Summoner12]

Here we draining down the pool. As we drained we swept the pool and kept the rover cruising around.



You can see the port where a rover could be connected, where the hose crosses over itself on the left wall. I keep telling my brother in law I want to dig down and follow the plumbing....



Working into the night... water starts flowing a bit faster at this point, well appears to



Spa drained down... is that texture supposed to be there? It looks neat, but not sure if it's intended.



Here is a close up of the plaster. When you brush you can see dust flying up...

 

[kimkats]

How did the "texture" feel in the spa? My guess is it is calcium build up or such. Did you do anything to clean it out?

I would be digging with you to find where that pipe goes.

Kim