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We've Been Asked... Algae Problems  
Algae - green, mustard, black, causes & cures.

Question:
My pool water has been diagnosed with having ammonia in it plus mustard algae.  We live
in the country and the farm fields are chemically treated.  All summer there has been no
chlorine reading and it has just now been found that perhaps ammonia has been blocking it. 
What is your opinion and how should I take care of the ammonia/algae problem??  We take
water samples regularly to the pool store for testing.  I am very frustrated with my pool
company...all summer I have purchased hundreds of dollars worth of products to take care
of the problem and no luck so far.   They do the Alex testing, but it has been a guessing
game with us.  Too expensive to guess!

Response:
I wanted to get back to you as quickly as possible.  The problem that you've been dealing
with is probably a bit more complicated than what you've mentioned.  If there have been
fertilizers added locally, you're almost guaranteed that some of it has & continues to drift
into the pool -- and it doesn't take a lot.  You may want to read our article on
Phosphates & Nitrates (ammonia is a chemical combination of Nitrogen & Hydrogen).  You
can help treat the problem using PhosFree plus a real heavy duty shock - as much as 20 lbs.
(or perhaps more) plus per 20,000 gallons.

If you're not already using it, Optimizer Plus is a FANTASTIC product that really does a great
job of inhibiting any algae growth.  Optimizer Plus helps snuff out carbon dioxide in the water
which is a major food source of algae as it photosynthesizes.

Your problem is the Phosphate & Nitrates (unfortunately you won't be able to stop them from
coming in), plus a chlorine demand (from the incessant algae) which isn't being met & algae
which is basically out of control because it's continually being fed.  If you've been having a
problem with the water balance, I wouldn't be surprised.

Get the situation under control NOW & definitely don't winterize the pool in this condition. 
If you do, next year will be even worse.  We have had other customers with very similar
conditions & have successfully treated their pools so that are sparkling & clean & for all
practical purposes, algae free.  After the PhosFree is used, Optimizer Plus gets in there. 
Then it's just a regular weekly shocking with Smart Shock & a dosage of Back Up Algaecide.
 

Question:
We have had more rain and wind this summer and have had to fight
the yellow algae - we have
brushed and super shocked.
 

We have been told two different ways of when to put the algaecide in -so I would like your
opinion as to whether it goes in "before" super shocking
or "after".  Have always done it after
for years.  My theory is that when
you super shock it - takes everything out and if you put
the algaecide in before
it would take it out.

Response:
Our preference is to use the algaecide first & brush any algae that are clinging onto the walls
or floor.  Let it circulate for a good 1 to 2 hours, then shock the pool.

Adding the algaecide first allows it to attack or begin "softening up" the algae so that the shock
can better & usually more effectively kill the algae.  When you shock - you folks are probably
dealing with a chlorine demand as well - you may have to add 5 to 10 times the normal amount
of shock to effectively treat the problem.  If you don't do that, you'll keep playing with the algae
for weeks.  A "normal" 5 to 10 lbs just isn't going to do it.

This year 2006, we found that properly treating chlorine demands the first time (sometimes adding
25 to 50 lbs of shock at once), treats the problem once & for all.  Oftentimes, that's what it takes.
 

Question:
We live in Orlando Florida, and are relatively new to owning a pool.  Ours is an in-ground somewhat
kidney shaped pool, approximately 17x32.  In the last 2 days, we have been fighting a problem with
Algae.  The one we have was "diagnosed" as mustard algae by our local pool supply store.  It is
yellowish, but looks green when brushed away, and tends to form into "piles" on the bottom of the
pool in yellow clumps.  We have a tablet chlorinator on the filter system, the filter is new, and we use
liquid chlorine.  We recently installed a pool heater as well, and are wondering if the heat is contributing
to the algae problem, as we have never had it this bad before.  The pool supply store recommended
using Muriatic Acid, the liquid chlorine, and the chlorine tablets, and said if we did the treatments today,
we could swim in 24 hours.  My husband actually had put the liquid chlorine in last night, and we used
the muriatic acid today.  The store said you could use the pool after 2 hours as far as the muriatic acid
was concerned.  This evening, I got into the pool to see if the chemicals would burn or cause me any
problems before I let my grandchildren in.  I did have some burning sensations, not bad, but enough to
keep me from allowing the children to get into the pool.  I am wondering if we are getting correct
information from our pool supply store, and are hoping you will give us additional (or correct) information,
as to what we need to be doing.

Response:
What you describe does indeed sound like mustard algae.  Now..., I hope that you've had a proper
water analysis done.  I don't like to hear that pool stores have you adding muriatic acid on a "willy-nilly"
basis.  That's only going to treat the symptoms & not the actual cause. Mustard algae is difficult to
deal with but is treatable.

If you're feeling that the water is uncomfortable, the water may be severely out of balance.  If you
can't find a good pool store to do a proper analysis, at least test it at home regularly & maintain a
pH of 7.4 - 7.6, total alkalinity of 125 ppm & calcium Hardness of 200 ppm.  Algae is much easier to
treat & cure when the water is in good balance.  Furthermore, using a product such as
BioGuard Optimizer Plus at the correct levels will virtually eliminate any algae problems. Period.
 

Question:
You mention small cell green algae (SCGA), which it is resistant to chlorine and seems to make chlorine
"disappear" and that sounds like what is happening in my pool this season.  I've used many bags of
powdered shock, gallons of liquid chlorinator and gallons of an algaecide/clarifier.  In the past few
weeks, I've spent big bucks on the above; have vacuumed daily both through the filter and to waste. 
The water is still not very clear, and it eats any chlorine I add in a matter of hours.

Response:
Constant algae blooms are a sign that you have a chlorine demand problem; in other words, you're
just not getting enough chlorine in the water at one time to kill off all of the "stuff", no matter
what it is.

Keep in mind that when you use liquid chlorine & gallon algaecide, you're using products that are
pretty well diluted.  When treating situations such as yours, always use the most concentrated
products you can.  They may cost more initially, but they'll do a better, more thorough job &
save you money in the long run.

Back to your chlorine demand problem.  Depending on your pool size, you'll probably START with
using 8 to 10 lbs. of shock (BioGuard Burn Out Extreme) per 10,000 gallons PLUS a good quality
algaecide (BioGuard Back Up or Algae All 60).  That may sound like a lot, but trust me, it's not.
Using Optimizer Plus will also further help because of the chemical reaction; the algae will not be
able to photosynthesize, when used in the proper dosages. SCGA needs to be treated
AGGRESSIVELY because it's very tough to kill.  My advice to you would be to find a local BioGuard
dealer who has the AccuDemand 30 chlorine demand test station.  They'll be able to properly
guide you.  If you can't find a dealer, you can overnight a 1 qt. water sample & we can perform
that test for you & make the necessary recommendations.  Make sure that the water is properly
balanced first.  That allows the chlorine to work properly & effectively. 
 

Question:
Help!!!! I can not get rid of the green stuff.  I have shocked the pool three times now and I still
have a light green look to the pool.  I have a 20X40 inground liner pool and the ph is between 7.2
and 7.8 and 120 and the chlorine level is off the charts.  I clean the filter regularly 2-3 times per
day and the green look just won't go.  What should I do?  Should I get an algaecide?  What would
you recommend as a program to get rid of it and then maintain it properly?

Response:
To be on the safe side, I would first recommend that you have the water checked for heavy metals,
copper in particular.  Oxidized copper will turn the water a light, clear green.  Treat with BioGuard
Pool Magnet - 1 qt. / 10,000 gallons / 1.0 ppm metals present. 

I would definitely treat with a good algaecide (BioGuard Back Up or Algae All 60 are both good 
products) if you haven't already done so.  Algicide should be added at start up, then weekly 
for the remainder of the season.
 
If you really want to keep algae at bay, BioGuard Optimizer Plus is a great algae preventative.  
When used properly, Optimizer Plus prevents algae from photosynthesizing & growing.  As a bonus, 
you'll notice better balanced water & a soft feel.  Most customers find a significant decrease in the 
amount of sanitizer used (works with any pool sanitizer) - up to 25% to 30% less.  Now that I've 
said that, I hope you don't live in California where it's not available for use.
 
Follow a good maintenance program of weekly shocking, algaecide & good chlorine levels plus good 
water balance.  You may find that BioGuard products are a little more expensive, but they just work 
better, so they end up being less expensive in the long run.

Question:
We have an above ground vinyl liner swimming pool.  We live in the country on a farm and every
year I have to replace the liner due to the fact that I keep getting what I believe is some type of
algae that I can not scrub off to save my soul.  It seems as if it welds itself onto the liner.  Also, it
feels like sand paper and will make your feet and hands very tender.

Response:
It almost sounds as if you may have some kind of ground fungus that's getting through the liner. 
You may have to use a ground cloth first then put the liner on top of it.  Check with a local nursery
or landscaper to see if they can recommend any kind of fungicide that can be put down as well. 
Purchasing a good quality liner will also make a difference.  Cheap liners are not treated as well to
guard against fungus & mildew.
 

Question:
I just cannot get rid of the green algae in my pool.  

There is not much clinging to the walls.  Tuesday and Wednesday I put 40 lbs. of chlorine in the
water.  I added a good algaecide and some clarifier.  The filter is relatively new (3 yrs); cartridge
(2nd set).  Pump is brand new.  The filter has been running non-stop for a week. 

Response:
You're doing all the right things.  Keep the chlorine high, maintain pH at 7.4 - 7.6, TA at about 120. 
Only clean the cartridges when they become really clogged & there's no pressure returning back
to the pool.  40 lbs may sound like a lot, but in a 20,000 gallon pool, that's not a lot especially with a
bad algae problem.  Remember, it took several MONTHS to get into this condition; it's not going to clear
in a matter of days.  It will be a slow process.  Keep brushing & the filter running 24/7 until clear. 


Question:

Is it safe to swim in a pool that has/is being treated for mustard algae? 

Response:
 
It's perfectly OK to swim in a pool that has been treated for mustard algae.
 
As long as the ph (7.4 - 7.6) & total alkalinity (about 125 ppm) are in balance & the chlorine level is 
under 3.0 ppm, you'll be fine. 
 
If there is still some mustard algae present, I would recommend laundering the bathing suits using a bit 
of bleach to make sure the algae is killed so as to not possibly contaminate another pool or spa.

Copyright© Par Inc. of Conn., Par Pool & Spa 2007