General start-up question

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Hmmmm, I may be missing something with all that math you just threw at me :(

We bought this house and they had been using pucks for years. At least 2-3 years, but likely more.

I also know that small water changes, or even overfilling and draining, isn't the same as simply draining the needed amount and then refill. But, are those pucks the pool place has in the strainers really replacing CYA I may drain off at a rate where I'm wasting my time entirely? I do know it's adding more back in, but I was thinking of reducing a three year accumulation.

LOL, I hope the newb phrasing makes sense :)
 
you are on it, If you have pucks in the pool, it is adding CYA... If you are draining and refilling but still have pucks, they are just adding CYA back in...

Do 1 or the other..

take pucks out, drain and refill and use liquid chlorine/SWG
or leave pucks in, do not drain, also use liquid chlorine, but know your raising CYA and will have to bring fc level up higher

It does not make sense to drain and refill and still use the pucks
 
As I said, they're rough numbers because I don't know how much you've drained or how many pucks are in the pool. Maintaining as opposed to rising CYA will help you limp along for the week without increasing the needed FC amounts. I do think you'd be better off taking them out and dosing with bleach to reach your FC goal.

Small, partial drains and fills are much less effective than a larger drain and fill.

You aren't necessarily reducing a three year accumulation - during that time the pool has likely been drained due to heavy rainfall which has helped some.
 
I have to say, you are just going to be spinning your wheels still to a point. You SWG is going to be over worked and destroying its lifespan. You will have to put in extra work keeping things balanced.

Even with your rainfall, I would get it down to at least the top of the recommended chart (80). What is another 1000g or so of drain vs the added headache?

Once you get it down if the rain comes and dilutes quickly, how difficult is it to raise it up 10ppm? Not that hard, or expensive.
 
Pucks are also gone, although the pool place will be back on Thursday and likely want to drop more. I'll be checking FC twice a day and using bleach otherwise. If they DO drop more pucks in I doubt it will add much more CYA in a short time until I find them and pull them out.

Otherwise, I'm well aware of many of the other inputs. I know fill and drain in small amounts isn't the same as draining 36% and refilling. Maybe I just talk to much, but I'm only doing what I can to start bringing it down until next week and THEN drain whatever is needed. However, please don't take that as a hint to shut up or anything, as I appreciated ALL of the input and by next week will likely need help from all. Just clarifying that I understand "those" things. My question was mostly about a puck or two replacing CYA as fast as my hose could dilute it. LOL, the pucks that are gone already if I had looked.

Pool is still not overflowing though, and I am really interested to see which direction it flows to. From midpoint of the strainer we keep it at to overflow is 9 inches of water but even after a quick nap it's still just short :(

Thanks for all the help from all!! In the end it WILL be drained as much as needed to get CYA down. Soon :)
 
I misunderstood. I thought you were going to ride it our until after your company, then drain to around 90 CYA. I was just saying you should lower to at least 80 after your company. If that is what you meant, I apologize! No offense taken btw.
 
You didn't misunderstand much :) I was shooting for 90 to start. All you missed was the temporary situation and me hoping to start drawing CYA down as I could, even if not in as efficient a manner as would be normal.

I also think I'd have a hard time offending anyone with a 1st Cav emblem as part of their signature :)
 
The Army in general does tend to thicken your skin a little! Cav is a whole other story...!

It takes quite a lot of toning down on my part to not get in trouble here on the other hand. I tend to be overly straight forward and often too sarcastic.
 

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With a high CYA level in a pool with a lot of sunlight on it you do NOT lose more FC per day even with a proportionally higher FC level. It is precisely for this reason that we have the SWCG CYA target be higher. It actually saves life of the cell. You are assuming that at the higher FC level there is a higher absolute loss because the loss is a percentage of the FC, but that is only true at a constant CYA level. Higher CYA levels protect the chlorine from getting broken down by sunlight and it does so in a non-linear way so a higher FC and CYA actually uses LESS chlorine. See the chart in this post to see what I mean.

So I see nothing wrong with just having an FC that is a minimum of around 5% of the CYA level, so 7 ppm FC with 140 ppm CYA. As shown in this post, the Hayward AquaRite T-CELL-15 outputs 1.45 pounds of chlorine over 24 hours so in a 15,000 gallon pool that is 0.483 ppm FC per hour. The FC loss per hour in direct sunlight at the 140 ppm CYA level should be less than 0.1 ppm FC per hour implying a % ontime needed to sustain the recommended chlorine level (i.e. 7 ppm) of around 20%, but only during the main daylight hours when most sun is on the pool. Because you need to last overnight as well, you'll want to run a little longer to go above 7 ppm so that you end up at 7 ppm for the start of the next day when the SWG comes on again.

This way you can take your time doing water dilution over time to get the CYA into a less risky level. The only real risk of the higher CYA level is if you were to get algae then SLAM levels are quite high so that's a lot of manually added chlorine that would be needed.
 
LOL, a SLAM would take a pickup truck load of bleach :)

Thanks for all that great info and links. I've even read all of those but it didn't fully click until you used mine for the example. You even did all that math to give me an idea of a starting point when I turn it on.

So, with all of that, I'm not going to worry about bringing it down entirely all at once, but I'd like it in the testable range to not have to mess around with using dilution just to know where it stands. Salt and water aren't nearly as expensive as all the bleach I'd need if I ever need a slam so I might as well bring it down.

Out of curiosity, does the UV reduction due to being in a screened enclosure have any measurable impact? Not that I need to measure it, just curious if it helps or is so minor it's effectively zero difference.
 
You all have covered a lot of math in this thread, most of which is above my head ;-).

I do want to say that you can maintain FC with your SWG. I live in Texas. My pool gets full sun. Summer time I've been running it at 50% for 6 hours a day, but the hours are spread out among the 24 hour day, not all 6 hours at once. In the cooler months, I drop to 30%-35%. I'm still learning, but the only time I've had to add bleach since my SLAM was when I was out of town and a dead rabbit landed in the skimmer. The poor SWG couldn't keep up with the organic matter the FC was using up. I got in from out of town and the FC was 1. Thankfully no algae and the CC was still 0. I added a gallon of bleach to get the FC back up and kill whatever yuck was left from the dead rabbit. FC has been holding fine ever since. In the future, based on the advice from this forum, in going to add bleach to shock level before going out of town - just to be safe!

PS - tell the pool company no more pucks! Liquid chlorine only.


Sent from my iPhone using Tapatalk
 
NeedMoreSun said:
Thanks for all that great info and links. I've even read all of those but it didn't fully click until you used mine for the example. You even did all that math to give me an idea of a starting point when I turn it on.
Click to expand...

Just so you know, some of the math is easy to do if you use Google (the general one in the browser or on Google's site -- not the site-specific TFP one) to do unit conversions for you. For example, type in

1.45 pounds per 24 hours per 15000 gallons in milligrams per hour per liter
Click to expand...
and you will get

0.482634221 (milligrams per hour) per liter
Click to expand...
which are the same units as ppm per hour. Though the calculations can also be done with my spreadsheet, these unit conversions are most easily done using Google. The trick is using "per" for division (for multiplication you just sequence the unit terms as in "kilowatt hour") and only use one "in" for the word that separates what you are going from to what you want to go to.
 
Well, CYA is showing 100 now, FC has only dropped to 10 though. I found there was a little bit of almost dissolved puck still in a strainer so I'm assuming that's why it hasn't dropped much yet. I've been ready with bleach but not needed any yet.

Anyway, I got my replacement Polaris pressure pump all plumbed up today, and with the electrical for that done finally started working on getting the Aqua Plus going. I've not set timers yet but I can turn everything on and off, change speeds, etc so all looks good.

Now a dumb question.... How do I know if the SWG is on or not? Not necessarily if it's REALLY functioning, but if the controller at least thinks it is. I want to play with my VSP speeds and find the low point where it cuts off, as well as I'd like a warm fuzzy that it at least thinks it's working. If I see a voltage reading in the diagnostics menu is that all I'm likely looking for? Well, along with the same menu showing flow and I'd assume once to low it will change to no flow.
 
Pogueld said:
You all have covered a lot of math in this thread, most of which is above my head ;-).

I do want to say that you can maintain FC with your SWG. I live in Texas. My pool gets full sun. Summer time I've been running it at 50% for 6 hours a day, but the hours are spread out among the 24 hour day, not all 6 hours at once. In the cooler months, I drop to 30%-35%. I'm still learning, but the only time I've had to add bleach since my SLAM was when I was out of town and a dead rabbit landed in the skimmer. The poor SWG couldn't keep up with the organic matter the FC was using up. I got in from out of town and the FC was 1. Thankfully no algae and the CC was still 0. I added a gallon of bleach to get the FC back up and kill whatever yuck was left from the dead rabbit. FC has been holding fine ever since. In the future, based on the advice from this forum, in going to add bleach to shock level before going out of town - just to be safe!

PS - tell the pool company no more pucks! Liquid chlorine only.


Sent from my iPhone using Tapatalk
Click to expand...

I missed this earlier somehow. A dead rabbit? Ewwww!! I'm really liking having an enclosure now, lol.
 
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