New pool owner first water test, need some advice

[Guest]

I am a first time pool owner, and just got K-2006 test kit today. Here are the results:
FC: 5
CC: 0
PH: 7.6
TA: 90
CH: 450 ( ~ 500)
CYA: 100 (maybe 110)

Very high CYA, I guess because my pool service guy use several 3" Chlorine Tabs every week...

Plaster pool. No SWG.

So, does this mean that I have to replace 50% of the water?
I have a hayward multiport value (SP740DE), filter-backwaste-booster-waste. Should I use the waste port to drain the water?
Could someone give me any advice on how to replace the water? and roughly how long it will take for the who process, given that my pool is about 15k gal.
Thank you so much in advance!

 

[linen]

Welcome to tfp, snuzxj

Yes, a partial drain/refill would be our first suggestion. The waste port is right for draining.

Do you know your ground water level? If it is high, then be careful about draining too much at one time...the ground water can float your pool.

Could someone give me any advice on how to replace the paper?

I don't understand this question..."replace the paper"?

 

[Guest]

Thank you, linen!
My pool is in ground, but the ground level is higher than neighbors. But I don't know the exact ground water level...
I really appreciate your pointing this out. Is there anything else I should pay attention when I drain/refill my pool?
Sorry for the typo... Not "paper", should be "water"

 

[Richard320]

Hopefully you have a valve to isolate the drain from the skimmers, because otherwise when the water level gets low, the skimmer will start sucking air and you will lose the prime and run your pump dry. That's not good for it. Think big $$.

And from personal experience... if you buy a backwash hose to hook onto the waste port: when you unroll it to wherever the water is to drain, be sure there are no kinks or twists in it anywhere. It will ballon and pop before you can get back to the switch!

 

[Guest]

Thank you for your advice, Richard!

I checked, there is 2 main drain on the floor, and there are separate cutoff values for main drain, skimmer, and cleaner (suction side). I will cut the skimmer and cleaner line off, and leave main drain on.

As for the backwash hose, I almost headed off to pool store to buy one yesterday, but found that the waste (backwash) line to the multiport valve is "close-end", connecting somewhere underground (maybe sewer system). I guess, in this case, I don't have to worry about the waste water, is that right?

Thank you again for your kind comments!

 

[ping]

It seems you are set up nicely with the main drain isolation and your waste line setup to the sewer.

You might want to check the CYA with half tap water and half pool water to get a better idea of your CYA level. You want to multiply your result by 2. When the CYA test measures above 100, it could very well be much higher than 100 as the test is logarithmic.

 

[Guest]

Hopefully you have a valve to isolate the drain from the skimmers, because otherwise when the water level gets low, the skimmer will start sucking air and you will lose the prime and run your pump dry. That's not good for it. Think big $$.

And from personal experience... if you buy a backwash hose to hook onto the waste port: when you unroll it to wherever the water is to drain, be sure there are no kinks or twists in it anywhere. It will ballon and pop before you can get back to the switch!

Another question:
My pool looks perfect for now even with 100+ CYA (as the test result in OP)
Should I still need to replace the water, or hold it until there is some problem?

 

[Richard320]

Another question:
My pool looks perfect for now even with 100+ CYA (as the test result in OP)
Should I still need to replace the water, or hold it until there is some problem?

From my response in this thread about 2 weeks ago.

When I took over my pool, I got somewhere between 220 and 240 on CYA, because the previous homeowner and his inept pool service used pucks exclusively. There were a few other deficiencies, but that's another topic. I was under water restrictions that year, so draining was not an option. I would have ended up with a hefty bill, and a water restrictor installed on my meter at my expense...

It CAN be maintained with astronomical CYA, but it is not easy, nor would I recommend it. Just for starters, the pH test will always be iffy, because the FC level has to be kept so high. And the color block quick test for FC is useless. The only way to test FC is the FAS-DPD test every day.

By watering my lawn with pool water then refilling, and capturing rainwater from the gutter downspouts I was finally able to get CYA down to 40ish in about a year. It's much easier to maintain with low CYA. I can eyeball the OTO test and know if I need to add bleach or not, the pH test is accurate, and I have enough breathing room on the CYA that I can use pucks when I leave town.

 

[anonapersona]

Another question:
My pool looks perfect for now even with 100+ CYA (as the test result in OP)
Should I still need to replace the water, or hold it until there is some problem?

Doing it in one step rather than many steps is more water efficient. For example, if you needed to replace half the water you could drain the pool about halfway, then refill once. Or you could do a 10% drain, refill, then repeat.... but you will have to do this more than 5 times to replace 50% of the water for the second time you drain some water, some of it is the water you just added. It gets to be rather wasteful. Especially if you are also having to re-balance the pool water after each refill.

You will want to get a test of the fill water, CH, TA, and possible metals. This will give you an idea of what to expect when you refill the pool. Don't bother testing CYA or pH or FC of fill water. CYA will be zero, and pH and FC will change after the water has been at normal pressure and exposed to sunlight.

 

[Guest]

Doing it in one step rather than many steps is more water efficient. For example, if you needed to replace half the water you could drain the pool about halfway, then refill once. Or you could do a 10% drain, refill, then repeat.... but you will have to do this more than 5 times to replace 50% of the water for the second time you drain some water, some of it is the water you just added. It gets to be rather wasteful. Especially if you are also having to re-balance the pool water after each refill.

You will want to get a test of the fill water, CH, TA, and possible metals. This will give you an idea of what to expect when you refill the pool. Don't bother testing CYA or pH or FC of fill water. CYA will be zero, and pH and FC will change after the water has been at normal pressure and exposed to sunlight.

I also prefer to doing one time water refill. Although Richard's method will eventually reduce the CYA, it takes too long and too many efforts. I was in hope that CYA would be reduced by itself, which seems impossible...

I appreciated you mentioned to test the tap water, it definitely will give me an estimation of what the water would be after I refill the pool.

 

[Guest]

From my response in this thread about 2 weeks ago.

Thank you for the pointer.
I have read a lot of your replies in TFP :-D
But your way seems too hard for a first time pool owner like me...

 

[Richard320]

From my response in this thread about 2 weeks ago.

Thank you for the pointer.
I have read a lot of your replies in TFP :-D
But your way seems too hard for a first time pool owner like me...

That's why I don't recommend it. But I didn't have much choice that year.