Cyanuric Acid blues - draining pool

tlwilson

0
LifeTime Supporter
Aug 15, 2010
50
Nebraska
I have tested several times and finally believe it. My pool's Cyanuric Acid level is between 85 and 100, so I am going to drain half my pool before the swimming season gets started here. I will also quit using Leslie's 3" pucks and start sanitizing with Chlorox. :-D I have a submursible pump set on the bottom step. I'd like to drain even more out, thinking I need to remove most of the water in the shallow end to achieve a 50% reduction. Will it damage the vinyl liner to set the submrusible pump directly on the liner?
 
Will it damage the vinyl liner to set the submrusible pump directly on the liner?
Nearly impossible. I suppose there might be a circumstance under which the liner could be sucked up into the intake but that would be a phenomenal event.

You could always submerge a couple of bricks to set the pump on if you wanted to be stunningly safe.
 
I thought the recommendation was to leave at least a foot of water in the shallow end to ensure the liner does not shift. If you leave the pump on the step you are probably ok, but pay attention if you are going to drain more.

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tlwilson said:
I have tested several times and finally believe it. My pool's Cyanuric Acid level is between 85 and 100, so I am going to drain half my pool before the swimming season gets started here. I will also quit using Leslie's 3" pucks and start sanitizing with Chlorox. :-D I have a submursible pump set on the bottom step. I'd like to drain even more out, thinking I need to remove most of the water in the shallow end to achieve a 50% reduction. Will it damage the vinyl liner to set the submrusible pump directly on the liner?


Cya of 85 to 100 is high, but not unmanageable. I'd leave it, and just stop adding more with pucks. It will slowly drop as the kids splash water out.
 
texasdad said:
tlwilson said:
I have tested several times and finally believe it. My pool's Cyanuric Acid level is between 85 and 100, so I am going to drain half my pool before the swimming season gets started here. I will also quit using Leslie's 3" pucks and start sanitizing with Chlorox. :-D I have a submursible pump set on the bottom step. I'd like to drain even more out, thinking I need to remove most of the water in the shallow end to achieve a 50% reduction. Will it damage the vinyl liner to set the submrusible pump directly on the liner?


Cya of 85 to 100 is high, but not unmanageable. I'd leave it, and just stop adding more with pucks. It will slowly drop as the kids splash water out.

Yep, this is what I did last year when I found TFP and quit my puck habit. It was at about 90/100, and it came down to 50 (before I got a pool plumbing leak and it went down to 10, LOL.)
 
Cya of 85 to 100 is high, but not unmanageable.
The shock value for CYA of 100 approaches 40ppm. The maintenance FC values for CYA of 100 should be somewhere around 8-12ppm kept in the pool at all times.

Anecdotal success of someone's pool who chose to live with that CYA value is often not good advice. It is very difficult for the average owner to maintain his FC that high and the forum discourages anyone to attempt it. Your pool water management becomes much easier when your CYA in a manually chlorinated pool is around 50ppm.
 
With 2 submursible pumps I reduced water by about 40% and then filled it back up overnight. I don't want to see my next water bill. Pool is full, filter pump is running and I'll look at my numbers tonight after work. With the filter pump running all day, is that enough time to get the water circulated enough for a good test tonight?
 
Yes, your water should be circulated just fine. One word of caution, I hope your CYA is 50 or so but don't be overly discouraged if it is not. There are lots of reports on the forum of the drain and refill not yielding quite the reduction that it should. I can't explain exactly why although I suspect it is difficult to really drain as much as you should and most tend to drain a little less. Let's see how it turns out. :lol:
 

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Should I lower the Alkalinity since it is a little high?
You copuld but I wouldn't if it was my pool. Watch your pH. If it starts to go up, bring it down with acid and then lower the TA using the method described in Pool School.

Now, raise your chlorine up a bit and keep it between 4-6ppm (per the CYA/FC chart in pool school) all the time and you will have a great swimming season. Very nice work! :lol:
 
jblizzle said:
I thought the recommendation was to leave at least a foot of water in the shallow end to ensure the liner does not shift. If you leave the pump on the step you are probably ok, but pay attention if you are going to drain more.

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I agree with you, this isn't really an issue of will the vibrating pump damage the liner (it can, but unlikely) but you need at the very least 6 inches (that is cutting it very short) in the shallow end to hold everything in place, one foot should be a safe level.
 
Hi - I'm facing a similar issue to reduce CYA by draining off the water as the OP did. My calcs show I need to get rid of 50-60% of the water.

My question is, by leaving a foot in the shallow end, how much water am I removing during a drain/refill process? Would seem that leaving the foot of depth in the shallow end would only be removing 30% tops of the total volume of a 16x32 rectangular? Of course this is just visualizing it in my mind. I'm sure I need to do the volume calculations to get this figured out.

Thanks all.
 
I've been reading this thread as well as others regarding the cyanuric acid curse. My pool has been in service for less than 1 year and the CYA level is already over 100. Not that many pucks have been used.. and the pool is big. I think the pool service company anticipated rain dilution over the winter, which didn't happen. Partly because I kept the pool covered and pumped the water off the cover and partly because there wasnt that much rain. So, I'll have to drain and refill. The water I must use is relativly clean, but not city or well water. It will contain some contaminants including some algae. The strategy is as follows.
1. Shock the pool heavily
2. Turn off all filtration after shock is complete
3. Start adding new water at approx 20 GPM at the bottom of the deep end. Put a diffuser on the hose end to minimize mixing
4. As the water rises, it will flow over the low dam wall and out the drain in the cover well.
5. Because the incoming cold water is dense, it will stay on the bottom and the warmer water will flow out over the cover dam wall.
6. In around 18 hours, about 50 percent of the water will be swapped, with some allowance for mixing
7. Turn on filters, reshock and balance
So, thats the plan. Any thoughts? Thanks.
 
For what it's worth--concerning sub pumps sitting on liner earlier in thread.
I've taken a 5 gal bucket, and drilled about 7 or 8 1 1/2" holes out of it near the bottom (on the sides of the pail). Set your pump inside the pail, and lower the pail in the pool with a rope. No chance of damaging liner, and easy in/out of the pool with the rope.
 

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