Getting ready to drain & refill...what do I need to know?

[azkevman]

I am going to begin to drain my pool this evening due to high CYA (190)...as I have been discussing here: First Test = Worst Fears Realized...

Based on my CYA level, I assume I need to replace 100% of the water to just start fresh?

Do I just turn on the pump and drain the whole thing at once, or is there any reason i need to do this in stages?

Also, I believe I may have a couple spots of black algae, and assume I should attack those when its drained...but not sure how?

Then once I refill do I just go straight to balancing chems, or do I have to do a period of shock level, etc?

 

[zea3]

Re: Getting ready to drain & refill...what do I need to know

Make sure your local municipality does not have any restrictions on where the water from the pool is discharged. Also if your sewer charges are linked to water usage then letting them know you are filling a pool usually gets you a break on the sewer charge.
I would not drain 100%, maybe 90% at most. No point in buying more of what you already have (CYA)!

The black spots can be treated with a 75/25 solution of water (75) and bleach (25). Mix solution in a spray bottle, spray on spots and brush with wire brush. Spray again after brushing and let sit for a minute then rinse with clear water.

Once the pool is filled test and balance the water. You can bring the FC to shock level and run the overnight test to make sure everything is killed.

 

[azkevman]

Re: Getting ready to drain & refill...what do I need to know

Arggggh...looks like the city states that pools must be drained into the sewer clean-out, which can only handle a max flow rate of 12gpm. I don't know if it's an actual ordinance, but the city website states "Pool water must be drained into the sewer clean-out. Pools MAY NOT be drained into the street, alley or neighboring properties" :x :x :x

How do I know if my pump flows more than 12gpm? This really throws a wrinkle in my plans....

As for as the sewer charge it looks like the city sets the rate each April only based on usage only from DEC-MAR. so draining/refilling a pool APR-NOV has no impact...so I should be good as far as my sewer rate goes.

 

[azkevman]

Re: Getting ready to drain & refill...what do I need to know

I would not drain 100%, maybe 90% at most. No point in buying more of what you already have (CYA)!

The black spots can be treated with a 75/25 solution of water (75) and bleach (25). Mix solution in a spray bottle, spray on spots and brush with wire brush. Spray again after brushing and let sit for a minute then rinse with clear water.

Good point on partial drain...and not reinvesting in something I just flushed down the drain...

Although, if I only partially drain, the couple spots I suspect may be black algae will still be under water, as they are on the floor of the pool. Can I still treat them with water covering them? How is black algae treated when the pool is full?

 

[krazykrames]

Re: Getting ready to drain & refill...what do I need to know

Pools MAY NOT be drained into the street, alley or neighboring properties

Drain it on your own property slowly enough that it soaks in.

 

[duraleigh]

Re: Getting ready to drain & refill...what do I need to know

Full or not full, you don't want to waste much time trying to treat black algae with a CYA of 190ppm or more....anything ovger 100 becomes almost unmanageable.

Drain 1/3 of your pool and then refill. Repeat. Repeat again. That should probably get you down to around 50 or so. Then you can treat the black algae, if that's what it is.

12 gpm is pretty generous so I think you are fine. If you are worried about that, buy a sump that only pumps that gpm and put it in the bottom of the pool.

You need to get that CYA out of their or struggle with the pool forever.

 

[azkevman]

Re: Getting ready to drain & refill...what do I need to know

Drain it on your own property slowly enough that it soaks in.

Unfortunately, not really an option here in my area. The desert hard pan means water flows across the ground and not into it. The rate I would have to drain the pool to contain it within my lot is just not feasible.

 

[azkevman]

Re: Getting ready to drain & refill...what do I need to know

Drain 1/3 of your pool and then refill. Repeat. Repeat again.

Just curious, why do you recommend doing it in phases instead of draining say 80% all at once?

12 gpm is pretty generous so I think you are fine.

Does my pump have a GPM rating? Supposedly the risk is too high of flow can cause the sewer clean out line to back up into the house... that would be bad.

You need to get that CYA out of their or struggle with the pool forever.

I hear you! I was ready to start pumping it out as soon as I saw my first test results last night.... unfortunately or fortunately doing my homework today so I can get going on it tonight.

CAN"T WAIT TO BE TROUBLE FREE!!!

 

[azkevman]

Re: Getting ready to drain & refill...what do I need to know

Well, heres an update....
I rented a couple submersible pumps and started them up last night. Had to go that route since my city requires it to be drained through the sewer cleanout at no more than 720gph, and my pool pump was outputting about 3,600gph through the backwash....a little too high to send down the cleanout!
I decided to just do 80% drain in one shot...which should be about when the level reaches the shallow ends. That will hopefully leave me right about where I want to be CYA wise after refill (fingers crossed).

[attachment=0:3j44k58z]uploadfromtaptalk1344095001293.jpg[/attachment:3j44k58z]

Getting excited about being trouble free soon!

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[azkevman]

Re: Getting ready to drain & refill...what do I need to know

Should I add anything while the pool is refilling, or wait until it is done filling and see where the numbers are?
I did run a test on the fill water and here are the results:

FC: 0.5
CC: 0.5
pH: 7.6
TA: 130
CH: 0

Since it is mixing in with the 20% of water I left in the pool I know these numbers will change as it fills.
Just not sure if I should be testing and adding bleach, etc. as it fills, or wait??

Really appreciate all the help I have gotten reading here on TFP and in the forums.

 

[azkevman]

Re: Getting ready to drain & refill...what do I need to know

Here are test results as of right now....pool is about 60% filled:

FC: 8.5
CC: 0.5
pH: 7.6
TA: 120
CH: 200

I am figuring its not worth testing CYA until its filled, but since I drained 80% of the pool, expecting it to be around 40.

I have been running the filter/pump the entire time I am filling it to circulate, mix, and filter the incoming water. I have also been brushing the entire pool every 30-60 minutes.

Depending on how much the FC dilutes with the remaining 40% fill water coming in, it may go below the target level of 5, so I will watch it and add bleach if it looks like its going to go below. I dont expect it will complete filling until the middle of the night so I will do an OCLT tomorrow. Does that seem appropriate?

Hope I am on the right track...

Oh, also when the pool was mostly drained I inspected for black algae and did not find any, woohoo!

 

[jblizzle]

Re: Getting ready to drain & refill...what do I need to know

Sounds like a plan. No real point in testing anything until it is full. Run a full set and then an OCLT test should let you know if you need to do the shock process.

Btw I highly doubt your fill water is a CH of 0ppm.

The idea of draining in stages was just a safety net for avoiding floating your pool. Not really a problem for most of AZ.

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[azkevman]

Re: Getting ready to drain & refill...what do I need to know

No real point in testing anything until it is full. Run a full set and then an OCLT test should let you know if you need to do the shock process.

OK, that's how I will proceed. Thanks for the confirmation.

Btw I highly doubt your fill water is a CH of 0ppm.

I was a bit skeptical of that as well, but thought maybe it was due to the fact that my fill water goes through my water softener??
I did not perform a second test of the fill water to confirm the first result.

The idea of draining in stages was just a safety net for avoiding floating your pool. Not really a problem for most of AZ.

OK, that makes sense.

Thank you for your response. I am feeling more comfortable with where I stand now.

 

[jblizzle]

Re: Getting ready to drain & refill...what do I need to know

wow. That is going to work the softener quite a bit to fill the entire pool ... Although it should help keep your CH low which its also a problem in this post of the country.

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[ultra800_96]

Re: Getting ready to drain & refill...what do I need to know

I believe you are correct on your ch=0 test. My softened water tests also at 0. That's what I'm using to top off with.

 

[azkevman]

Re: Getting ready to drain & refill...what do I need to know

I don't believe my entire fill will be soft water, as the softener only has the ability to soften a certain amount of water each day, and then hard water comes out until it regenerates overnight. So I would imagine the majority of my fill is actually hard water.
When I get a chance sometime, I will test the water when it bypasses the softener to compare.

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[azkevman]

Re: Getting ready to drain & refill...what do I need to know

OK. Refill is complete. Here is my latest test results:

FC: 5.5
CC: 0.5
pH: 7.6
TA: 130
CH: 140
CYA: 50 (slightly less, but I will use this as my number)

If I am correct in what I am learning in pool school, my TA is high and my CH is low...is that correct? I am heading to pool school now to learn about these two...any recommendations would be appreciated.

My target FC level is 6 based on CYA of 50, and I should never let it get below 4...so my question is, if I chlorinate in the evening do I bring it to 6, or do I bring it to a higher level expecting it to come down to the target level during the next day? Not sure on this??

Anything else I need to address, based on my test results?

 

[jblizzle]

Re: Getting ready to drain & refill...what do I need to know

You CH is a little low. TA is not really something you need to worry about, it will come down as you adjust pH down.

You need to boost the FC high enough that it does not drop below the minimum by the next time you test and adjust.

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[UnderWaterVanya]

Re: Getting ready to drain & refill...what do I need to know

FC: 5.5
My target FC level is 6 based on CYA of 50, and I should never let it get below 4...so my question is, if I chlorinate in the evening do I bring it to 6, or do I bring it to a higher level expecting it to come down to the target level during the next day? Not sure on this??

My pool tends to end the day about 5-5.5ppm and I have a similar CYA level. I pour in a 96 oz container of 6% bleach each evening adding about 3.4ppm which leaves it at around 8.5-9ppm in the morning. By mid day (the earliest anyone is likely to swim it's below the 8ppm top end goal for my CYA level when not shocking. Kids, sunlight and fun drive it back down to close to 5 or so and then we do it again. I tend to use the numbers in the pool calculator rather than the CYA chart but the process is similar. Even if the FC was 9 or 10 when people were swimming - this is well below shock value and fine so I'm not too picky about the volume of bleach required. If it says 85-105oz - I'm more likley to put in 96; because it works better with my helper (mentally disabled adult) if there is a routine. If things are too far off - I adjust things - but I try to keep the basics the same so he is able to feel like a part of things.

 

[azkevman]

Re: Getting ready to drain & refill...what do I need to know

You CH is a little low. TA is not really something you need to worry about, it will come down as you adjust pH down.

So, do I need to lower pH? I was under the impression 7.6 was a good range for pH...

You need to boost the FC high enough that it does not drop below the minimum by the next time you test and adjust.

OK, so basically I will need to get a feel for what my average daily FC consumption is, then add that to the min to get my dosing target...correct? Until I see what that daily average is, I am going to assume a daily loss of 3ppm to be safe. Does that logic seem ok?

Thanks for your reply.



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