very green water and very high level of chlorine

Algae problems in swimming pool water.
Green (cloudy) water or slimy pool walls.
Black algae. Mustard algae. Pink or white pool mold.
chem geek
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very green water and very high level of chlorine

Postby chem geek » Tue 29 May, 2012 01:42

We're talking residential pools, not commercial pools, and residential pools are not shut down because the FC is too high. Even commercial/public pools are not necessarily shut down when the FC is over 4 ppm. The limit in Florida, for example, is 10 ppm as shown here and Texas allows 8 ppm as shown here . The EPA limit of 4 ppm for drinking water is in the FIFRA rules for product labeling, but it is state and county regulations that determine the actual limit used in commercial/public pools.

I have the 2009 "CPO® Handbook, National Swimming Pool Foundation®" with front cover title "Pool & Spa Operator™ Handbook" right in front of me where on page 83 it talks about phosphates and nitrates being nutrients for algae, but nowhere does it even refer to phosphate removers (that's something I suggested they do in the future). Instead, they end with the following:

Since all the nutrients that algae needs, including phosphate and nitrate, are commonly available in pool water or are stored within algae, it is very important that disinfectant residuals be maintained at all times to prevent the growth of algae.


So when you are going to be referring to sources to bolster your argument, you should actually make sure they are truly consistent with the points you are making. In this case, they are not though I believe that is flawed and that the manual should refer to phosphate removers as another alternative to using algaecides when one is unwilling or unable to maintain a sufficient active chlorine (hypochlorous acid) level (i.e. FC/CYA ratio). In fact, the first paragraph in the Algicides section of the manual on page 82 states the following:

Disinfectants that chlorinate or brominate the water kill and prevent the growth of algae. Algae (and bacteria) prevention has driven more commercial facilities to install automatic chemical feeders, controllers, and probes to maintain adequate disinfectant levels at all times. Facilities without these mechanical systems are at a greater risk to have algae grow, since pool water almost always contains the nutrients algae need and there are likely times when the disinfectant is absent.


3 ppm FC would be OK if the CYA didn't get much above 30 or 40 ppm, but in pools that use stabilized chlorine, the CYA keeps increasing. High bather load commercial/public pools have most of the chloirne loss from bather load rather than from sunlight so have little need for a CYA level higher than around 30 ppm so there really is no excuse except that many such pools are unfortunately not using unstabilized chlorine (e.g. chlorinating liquid or a saltwater chlorine generator). Again, we've got tens of thousands of residential pool owners who manage their pools without phosphate removers, algaecides or other products -- just chlorine alone to control algae growth regardless of phosphate and nitrate levels. Because most chlorine loss in such low bather-load outdoor pools is from sunlight, the CYA level tends to be higher, around 50 ppm or so up to 80 ppm in sunny areas and in pools using SWCGs, BUT the FC level is raised proportionally relative to the CYA level -- that is the key to keep the same active chlorine (hypochlorous acid) level.

If you find it easier to use phosphate removers or algaecides at extra cost, then that's perfectly fine to do. Just don't fool yourself into thinking it is the only way to prevent algae growth.

By the way, when you refer to Ezi-Chlor, are you referring to the Clearwater Ezi Chlor peristaltic pump for automatically dosing chlorinating liquid or bleach or are you referring to Ezi-Chlor which is granulated Trichlor? If the latter, then for every 10 ppm FC you add, it also increases CYA by 6 ppm. That would not be keeping your CYA low unless you had significant water dilution. According to this MSDS , the product is a combination of Trichlor and borates where the latter helps balance the pH, but also accumulation of higher borate levels (around 50 ppm) is an algicide that you could instead separately add either from a combination of 20 Mule Team Borax and acid or from boric acid.

Also, you refer to having water with algae turn cloudy when you shock with chlorine as a bad thing, but that's what ANY chlorine source will do since it bleaches out the chlorophyll in the algae and then the algae needs to be further broken down or filtered out. Stabilized chlorine isn't the cause of that specifically. Cal-Hypo can cloud the pool if it is already saturated with calcium carbonate (e.g. a plaster pool).


Guest

very green water and very high level of chlorine

Postby Guest » Mon 23 Jul, 2012 12:43

I had the same problem last summer. We finally hired a pool man. I was spending so much money in chemicals. When the pool man came he said that the algicide I had poored in makes the pool use so much more chloiene. Hum the pool store forgot to mention this to me. The more algicide the more cloriene you will rip threw. The pool man used liquid cloriene and we ran the pump for several days t get it backk. Also, you need to drain and re fill the pool every few years. You have to start with fresh water sometimes.
chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

very green water and very high level of chlorine

Postby chem geek » Tue 24 Jul, 2012 20:57

If you manage your Cyanuric Acid level by not always using stabilized chlorine (Trichlor, Dichlor), then you wouldn't need to refill your pool water. The chlorinating liquid (same as bleach, but stronger in concentration) is key. You do want to have some water replacement over time so that the salt level is kept somewhat in check, but usually winter rains are sufficient for that (depending on where you live).
reacer2

very green water and very high level of chlorine

Postby reacer2 » Sun 01 Sep, 2013 16:49

joyschenck wrote:Hello
My problem started last week with my pool . On wed it looked alittle green so i went and purchased algecyde for the pool . the next day my pool was greener then the day before. So i put in more and it made it greener. I then got shock it for the pool and the water was clear but lots of alge on the bottom. I stir up the alge thinking that the filter would take care of it. but it didnt. So i was told to shock it again and use 2 bags. in which i did but water still really green and my chlorine level is really high.
Any advice as to what to do next??
racer2

very green water and very high level of chlorine

Postby racer2 » Sun 01 Sep, 2013 16:57

my pool 15,000 gallons it turned green on me i put in 5 gallons of clorinrine and yellow out which usually works but now its getting greeneri have a sand filter? whats going on.

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