So, is it safe to go in?

[morzh]

So, (measured with TFT kit, fresh) since I have

15ppm FC
0.5ppm CC
110ppm TA
7.4ppm Ph
200ppm CH
37ppm CYA

Is it safe to go in, say for a short time, or should I wait for another week?

I figure, if I deduct 1plm FC for every 10ppm CYA, I still have about 10ppm FC equivalent, maybe a tad less as it was measured 3hrs ago and it is a bright sunny day and it goes down by 2.5ppm a day (two days ago at the same time it was 20ppm).

What do you folks think?

 

[Texas Splash]

If we round-up your CYA to 40, the SLAM FC level is 16 and you are just under that. So if the water is clear, yes, you can swim.

 

[mknauss]

If the water is clear enough to see the bottom of the deep end - jump in!

Use 40 for your CYA - the vial you use is not designed for in between estimations.

Not sure what you mean on the deduct FC for CYA -- CYA buffers the FC, You can very safely swim in up to a FC of 16 with a CYA of 40.

Take care.

 

[AimeeH]

Why wouldn't you go in

It's safe to swim up to shock level for your CYA and you can't measure 37 accurately. I'd call that 40.

Jump in

 

[Donldson]

SI figure, if I deduct 1plm FC for every 10ppm CYA...

That's not how FC/CYA relationship works at all. SLAM FC is 40% your CYA number, which is generally considered 'safe' and is about the equivelent of 0.7 FC in unstabilized water (for normal CYA levels, things are a bit different as CYA gets too low or too high). Not that it is necessarily unsafe to enter the water above SLAM level, but A) it becomes less comfortable to swimmers and can become a problem to swimsuits and B) your FC shouldn't really be going above SLAM level very often if ever. Also your FC is not going to drop by 2.5 every day, as your FC gets lower your loss to sunlight will slow down as well. That's the biggest reason not to keep your FC at SLAM level all the time, you lose more FC each day than you do if you keep it in the target range.

 

[morzh]

Oh, the water's been sparkling since the opening day. My sole concern was the FC level.
Thanks guys! I

Ps. Is there a chart for safe levels of FC to swim in?
And minimum FC vs CYA that should be maintained for safe swimming?

 

[pooldv]

Yep, [FC/CYA][/FC/CYA], up to shock level is safe to swim.