Normal FC drop

[tim86]

is a FC drop of 3.5-4 daily drop normal if outside temp is close to 90, and water temp is at 81 with cya of about 35, pool is used basicly daily for least 1 hour and it located under a large tree, water is crystal clear and all other checmicals are in range, ph 7.2-7.4

 

[Perpetual summer]

That is probably normal for some pools, each one will be different and in different parts of the country will cause it to vary.
we have been also in a hot spell 90 +, I lost almost 5ppm with the heat and high bather load. Make sure you keep a close eye on fc during these hot days.

 

[tim86]

since i have a sand filter that needs to be backwashed weekly, and reg evaporation, do u think be fine to use the pucks in auto chlorinator if only put in one puck at time and at very low setting, since ill have eventuly add stablizer anyways,

 

[Jimrahbe]

tim,

Most pools use 2 to 4 ppm of FC per day. But as other have already said, each pool is different because of the environment it is in.

We are not against people using tabs as long as they understand what will happen and follow up with tests so that they know the status of their pool chemistry...

Tabs are not the problem, it is the lack of testing and a poor understanding of pool chemistry that causes most pools to turn green..

Thanks for posting,

Jim R.

 

[mknauss]

You would think that sounds logical. But - evaporation does not remove CYA. It stays behind. When you backwash, how much water do you have to add back in? Typically not much.

The problem with the theory is that you would have a moving CYA level,thus a moving FC need. Plus the acidity of the tablet could crash your pH unless you have high TA fill water and lots of aeration.

It would be helpful if you could fill out a signature -- Pool School - Read This BEFORE You Post

Take care.

 

[tim86]

i know whats involved with chlorine tablets, for every 10 ppm chlorine it adds 6 ppm stablizer, and lowers ph over time, i have 40 pucks left over, and just asking if i use one puck at a time only, and my chlorinate goes from 0-7, i have it at maybe .2, to where omost no water is flowing, if it would cause a huge issues, this way i can at least use tablets up, and no evaperation may not lower cya, but the water u re add to fill it up from the slow eveperate will dilute the cya slowly, so asking if between backwash and evap if amount stablizer added will more or less offset what little is lost. Pool is perfectly clear and balanced atm

 

[mknauss]

Again. The CYA does not leave the pool with evaporation. So if you take 1/10 of your water out of your pool due to evaporation, your CYA ppm would increase by 10%, until you added back that water (which has no CYA).

As Jim said, as long as you know what you are putting in your pool and it works for you - great.

Take care.

 

[tim86]

in your opinion do u think the amount of cya added by using chlorinator on low would add up to more then amount cya lost from water i lose weekly from backwash, im at 35-40 atm on cya and like keep it ruffly around there

- - - Updated - - -

it will not be my main source of chlorination

 

[mknauss]

Based on you data above, you stated 1 tablet would add 6 ppm stabilizer. If you have 40 ppm in the pool, to stay steady each week you would need to remove 15% of your water each time you backwash. You do not state the volume of your pool in your signature, (would be great if you would set that up), but that might be a bit more water than you normally use to backwash.

Take care.

 

[tim86]

guessing close to 10k but not easy to figure out due to fact the the drop from deep to shallow isnt as graduale as most and half way down walls sloap in also, and ill just remove puck and not worry about it

 

[tim86]

lol pool not in best shape, built in late 1980s, liner is new, but roots are growing under liner, omost entire distance of pool, and top step of pool is cracked bad, patch for now but needs be replaced

 

[proavia]

Your best bet is to save those tablets for when you go on vacation.

With an FC loss of 4, I'd be inclined to perform an OCLT - Pool School - Perform the Overnight FC Loss Test (OCLT) - to see how much you lose overnight. That will give a much better indication of whether anything needs to be addressed regarding your daily FC loss.

Can you post a full set of test results from your own test kit?
What test kit are you using?

Please complete your signature as outlined here (include teskit info): Pool School - Getting Started
This helps us provide quicker, more consistent advice - and we don't have to continually ask for the information each and every time you post.

Thanks!