Started my experiment with bleach

[Steve]

Help me understand a few things as I have been out of the industry a while now...

My recollection of bleach was that it dissipated very quickly in the water making it not as cost effective as some would assume, had a very high pH, was more dangerous to handle and was more effective in a swimming pool application for treating algae. Bleach was a very poor choice of sanitizers for sustaining chlorine readings and “could” be used as a shock if that was all you had. I also heard that it voided some warranties. Dunno if that was really true though…  :-?

In over a decade of water testing, I found that draining a spa every 3-4 months made the CYA reading a moot point as very rarely did it play a factor so utilizing bleach to address it was pointless. TDS was far more critical and had a greater impact on the effectiveness of the sanitizer and other readings.

Steve

[tony]

Help me understand a few things as I have been out of the industry a while now...

My recollection of bleach was that it dissipated very quickly in the water making it not as cost effective as some would assume, had a very high pH, was more dangerous to handle and was more effective in a swimming pool application for treating algae. Bleach was a very poor choice of sanitizers for sustaining chlorine readings and “could” be used as a shock if that was all you had. I also heard that it voided some warranties. Dunno if that was really true though…  :-?

In over a decade of water testing, I found that draining a spa every 3-4 months made the CYA reading a moot point as very rarely did it play a factor so utilizing bleach to address it was pointless. TDS was far more critical and had a greater impact on the effectiveness of the sanitizer and other readings.

Steve

Adding bleach to the water will increase the free chlorine level and sustain it as long as any chlorine.  As with any chlorine, it works best if there is some stabilizer (CYA) present (30-40 ppm).  It does dissipate sitting in the bottle unused after a period of time or more accurately looses some of its strength.  Bleach or liquid chlorine is also sensitive to sunlight so it must be stored properly.  It does have a higher pH, about the same as lithium hypochlorite but does not add any where near the TDS.  CYA also adds to TDS.  Most manufacturers do not like the use of bleach.

[Vinny]

I haven't done the cost per use breakdown so here it is: 96 oz of 6% bleach costs approx $1.50 and a 400 gallon tub takes about 2 1/2 oz to reach 3 PPM (I will use 3 oz for calculation simplicity), that would give a months worth of daily doses (actually 32 days) without using it for shock; 1.50 x 12 = $18.00. Dichlor would be around $30 so it is a little cheaper but you still need dichlor before using the bleach to get some CYA (20 to 30 PPM) into the tub.

Now for some thoughts on bleach vs all other chlorine. All chlorine acts the same on bacteria or algea as long as you use the proper amounts to get the desired effect. Trichlor adds CYA and is acidic, Dichlor adds CYA and is neutral, cal hypo adds calcium and I believe is alkaline and bleach adds salt and is alkaline. All chlorine apparently adds salt but 1/2 of what bleach does and all chlorine adds to the TDS of the water.

My water's PH stayed about the same while using bleach. Apparently, the reaction of using the disinfection ions (can never remember the names of the 2 ions) is acidic and counteracts the alkalinity of the bleach.

I can't comment on the "lasting" time of bleach in my tub because my tub seems to retain chlorine at times whether it's from bleach or dichlor; if anything I think it lasts about the same but I can't be positive.

The CYA is the real issue as it builds up over time. Yes, chlorine does kill most bacteria at a 300 PPM level but it's power is greatly reduced. If you use 3 PPM of dichlor at a time it adds about 2.7 PPM of CYA.. If you used the tub 6 days and shocked to 10 PPM on the seventh that would be 2.7 x 6 = 16.2 + 9 (shock) = 25.2 PPM per week; so 100 PPM can be achieved in a month depending on use. Of course not using the tub will reduce the amount of CYA in the tub. After about 30 PPM CYA chlorine has lost it's effect on the hot tub itch bacteria if it gets introduced. This bacteria needs a total contact time (minutes) and dose (chlorine) number of 2500 to consider it disinfected, chlorine effectiveness loses it's strength as CYA builds and higher levels of chlorine are needed to keep this bacteria in check.

The truth is - most people don't have to worry about the hot tub itch bacteria, using bleach seemed to be a little more of a hassel than granuals, draining water every 3 to 4 months is the most effective way to deal with the water, some people seem to want to keep their water forever and learning something new is FUN!

[Nitro]

Vinny,

Glad to hear bleach is working out for you. I've been using it for 3 months now with zero problems. To me it's a no brainer. It's cheaper, easier and safer than using Dichlor alone.

As a matter of fact I turned two people on to using bleach. One coming from Bromine, and the other coming from a Copper based system. Since they've been on Bleach, they couldn't be happier.

Anyone using Dichlor, should seriously consider switching to the Dichlor/Bleach method. As far as the hot tub warranty, there is no possible way a manufacture (or anyone) can determine you were using bleach instead of Dichlor in your hot tub, IF you have CYA also. They are chemically identical in the water.

[cashews]

I've just started using bleach this month. I'm glad it's so cheap and that it won't raise my CYA level!  8-)

 hi nitro!