Problem Solving - Some Frequently Asked Questions

The following Technical Information Bulletin comprises a selection of "Frequently Asked" technical questions.  Many of these have been adapted from the BioGuard Product Reference Manual issued to participants at the annual BioGuard workshops. Technical problems are often the subject of Technical Information Bulletins; consult your BioGuard Account Manager or check the Bio-Lab website for updates.

A. Green Water
B. Cloudy Water (White, Grey or Blue, not Green)
C. Cannot Maintain Chlorine Residual
D. Metal Stains or Coloured Water
E. Black Spot Algae
F. Mustard Algae
G. Pink Slime (Pink or Red Algae)
H. Pool Goo or Pool Tar
I. Disappearance of Cyanuric Acid
J. Purple Deposits Around Skimmer or at Waterline
K. Products Compatible with Ionisers, Ozonators and Salt-Chlorinators

 

A. Green Water

The following set of questions will help identify the most probable cause of green water and direct the best recommendation to remedy the problem as quickly as possible.

Question Action
A1 Is the water cloudy or hazy? Yes: Question A3.
No: Question A2.
A2 Is the water clear with a greenish tinge? Yes: Question A3.
No: Question A3.
A3 Is the pH of the water within normal range
(7.4 - 7.6)?
Yes: Question A4.
No: Adjust pH, then proceed to Question A4.
A4 Has there been a recent problem with low pH
or low Total Alkalinity?
Yes: Question A5.
No: Question A5.
A5 Have you found copper and/or iron in the
pool water?
Yes: Treatment A1.
No: Question A6. The water must be tested for
metals before treatment can begin. In determining
the origin of these metals, it is advised that the
source water be checked for copper and iron,
too.
A6 Are you able to keep chlorine in the water? Yes: Question A7.
No: Treatment A2.
A7 A7 Have you recently opened the pool for the
season?
Yes: Treatment A3.
No: Question A8.
A8 A8 Have you recently drained or refilled the
pool?
Yes: Treatment A3.
No: Question A9.
A9 Has the pool recently been re-surfaced?

Yes: Treatment A3.
No: Contact Bio-Lab.


Treatment A1 - Copper and/or Iron in Water:

Treatment A2 - Algae:

Treatment A3 - Trace Organics:


B. Cloudy Water (White, Grey or Blue, not Green)

Cloudy water is one of the most common complaints of customers. Treatment depends on the cause and rarely is there an overnight cure, although Super Clear Tabs, Polysheen Plus and Quick Clear can often be used to speed up the removal of particulate (undissolved) matter from the water. In all cases of cloudy water, the very first thing that must be checked is the filtration system. The following are questions you should ask to identify the probable cause and, in turn, enable you to prescribe the most suitable remedy.

Question Action
B1 Is the pH of the water within normal range
(7.4 - 7.6)?
Yes: Question B2.
No: Treatment B1.
B2 Has the filter been cleaned recently? Yes: Question B3.
No: Treatment B2.
B3 Has the filtration system been checked for
broken or worn parts?
Yes: Question B4.
No: Check filtration system.
B4 Are there any broken or worn parts? Yes: Treatment B2.
No: Question B5.
B5 Has the pool maintained a steady chlorine
residual of 1 ppm or greater for the past few
days?
Yes: Question B6.
No: Treatment B3.
B6 Is the total alkalinity of the water high? Yes: Treatment B4.
No: Question B7.
B7 Is the calcium hardness within range (plaster
200 - 275 ppm, vinyl 175 - 225 ppm)?
Yes: Question B8.
No: Treatment B5.
B8 Does the pool use calcium hypochlorite (eg.
BioGuard Cal Chlor CLC) for normal
chlorination?
Yes: Treatment B5.
No: The water appears to be in good balance and
has no chlorine demand. In all probability, the
customer has a filtration problem they are not
aware of. Suggest that they have a serviceman
check the filtration system

 

Treatment B1 - pH:

Treatment B2 - Filtration Problems:

Treatment B3 - Chlorine Demand:

Treatment B4 - Water Out of Balance:

Treatment B5 - High Calcium Hardness and/or Excessive Use of Calcium Hypochlorite:

 

C. Cannot Maintain Chlorine Residual

If a customer cannot get a chlorine reading or keep chlorine in the water, the following questions should be asked before a recommendation can be given.

Question Action
C1 Is the pH within range (7.4 - 7.6)? Yes: Question C2.
No: Adjust pH, then proceed to Question C2.
C2 Is the stabiliser (cyanuric acid) 30 ppm or
above?
Yes: Question C3.
No: Raise stabiliser level to at least 30 ppm and
proceed to Question C3.
C3 Have you double-checked the chlorine
reading by diluting test sample with tap water
(1 part sample to 4 parts tap water) and retesting?
Yes: Question C4.
No: Dilute sample as directed, then multiply
reading obtained by 5 to get Free Available
Chlorine (FAC) level. Then proceed to Question
C4.
C4 Is the Free Available Chlorine (FAC) reading
still zero?
Yes: Treatment C1.
No: Question C5.
C5 Is the Free Available Chlorine (FAC) greater
than 5 ppm for a residential pool, or 10 ppm
for a commercial pool?
Yes: Treatment C2.
No: Contact Bio-Lab.

 

Treatment C1 - Chlorine Demand:

Treatment C2 - Too Much Chlorine:


D. Metal Stains or Coloured Water

The following questions will help you to identify the potential problem but not necessarily the cause. Given that you can't always explain to a customer why a stain occurred, your main goal should be to remedy the situation.

Question Action
D1 Is the pH within range (7.4 - 7.6)? Yes: Question D2.
No: Adjust pH, then proceed to Question D2.
D2 Has there been a recent problem with a low
pH and/or total alkalinity?
Yes: Question D3.
No: Question D3.
D3 Has the pool water been tested for iron,
copper and manganese?
Yes: Question D4.
No: Perform tests, then proceed to Question D4.
D4 Has MSA II, Back-Up II or Protector been
added to the water?
Yes: Question D5.
No: Question D6.
D5 Were levels of copper in excess of 0.8 ppm
and/or iron and/or manganese in excess of
0.1 ppm detected in the pool water?
Yes: Question D7.
No: Question D7. There can be metal stains
even though no metals have been detected in the
water. All this means is that the metals have
completely precipitated out of solution.
D6 Were levels of copper and/or iron and/or
manganese in excess of 0.1 ppm detected
in the pool water?
Yes: Question D7.
No: Question D7. There can be metal stains
even though no metals have been detected in the
water. All this means is that the metals have
completely precipitated out of solution.
D7 Does the pool have a heater? Yes: Question D8. High levels of copper may
indicate that the heater element or exchanger is
corroding. If this is suspected, advise the
customer immediately to minimise further heater
damage.
No: Question D8.
D8 Is the fill water from a bore or some other
groundwater source (ie. not municipal
water)?
Yes: Question D9. Apart from calcium, bore
water is often high in metals like copper and iron.
No: Question D9.
D9 Has the source water been tested for metals
recently?
Yes: Question D10.
No: Test source water for metals, then proceed to
Question D10.
D10 Does the source water contain metals in
excess of 0.1 ppm?
Yes: Treatment D1.
No: Question D11.
D11 Is the water discoloured? Yes: Note colour and check Table below, then
perform Treatment D2.
No: Question D12.
D12 D12 Can the stain be removed or partially
removed with brushing?
Yes: Stain is most probably due to algae. See
sections on treating black spot, mustard algae
and pink slime, below.
No: Note colour and check Table below, then
perform Treatment D3.


Table - Metal Stains and Discolouration

Metal Surface Stains Water Discoloration
Iron Brownish
Rust colour
Orange/Brown
Rust colour
Light brown
Greenish
Copper Blue
Black
Grey
Turquoise Green
Deep Blue
Grey (not common)
Manganese Black
Dark Brown
Coffee Brown
Violet Purple

 

Treatment D1 - Metals in Source Water:

Treatment D2 - Discoloured Water Due to Metal Ion Contamination:

Treatment D3 - Metal Stains:

 

E. Black Spot Algae

The following questions are used to determine if the customer has black algae.

Question Action
E1 Are the black spots raised on the pool
surface?
Yes: Possibility of black spot algae. Go to
Question E2.
No: Question E2.
E2 Do the spots feel slippery or slimy? Yes: Possibility of black spot algae. Go to
Question E3.
No: Question E3.
E3 Can the spots be removed partially or totally
by brushing?
Yes: Black spot algae confirmed. Perform
Treatment E1.
No: Black spot algae unlikely. Go to Question E4.
E4 Is the pool surface fibreglass? Yes: Possibility of black spot osmosis due to
damaged gel coat. Perform Treatment E2.
No: Most likely metals-related. See section on
metal stains, above.

Treatment E1 - Black Spot Algae:

 

F. Mustard Algae

The following questions are used to determine if the customer has black algae, mustard algae or a stain of some sort. After determining that they do have one of the two then you can prescribe a treatment.

Question Action
F1 Is the surface growth a yellowish-orange to
mustard colour?
Yes: Possibility of mustard algae. Go to Question
F2.
No: Question F2
F2 Does it readily brush off like a powder, only
to return shortly afterwards?
.Yes: Possibility of mustard algae. Go to Question
F3.
No: Most likely metals-related. See section on
metal stains, above.
F3 Has the water maintained a 1.0 - 3.0 ppm
chlorine residual for the past couple of days?

Yes: Mustard algae confirmed. Perform
Treatment F1.
No: Satisfy chlorine demand (see above,) then
perform Treatment F1.

 

Treatment F1 - Mustard Algae:

 

G. Pink Slime (Pink or Red Algae)

Pink slime is a surface growth that is caused by bacteria (to be precise, Methylobacteria) and is often mistakenly called pink or red algae. Here are some questions that should be asked before a recommendation can be given.

Question Action
G1 Does the growth feel slimy or slick? Yes: Question G1.
No: Question G1.
G2 Does the slime brush off the surface
relatively easily?
Yes: Pink slime confirmed. Go to Question G3.
No: If the pool is vinyl-lined, the pink colouration
could be due to a fungus that grows underneath
the liner. Unfortunately, this discolouration
appears to be permanent and no treatment exists
for its removal.
G3 Has the water held a steady chlorine residual
between 1.0 - 3.0 ppm for the past couple of
days?
Yes: Treatment G1.
No: Satisfy chlorine demand (see above,) then
perform Treatment G1.


Treatment G1 - Pink Slime: 

Prevention of Pink Slime:


For further information on this topic, see "Pink Slime", Bio-Lab Australia Technical Information Bulletin BG-027.

 

H. Pool Goo or Tar

The following questions should be asked to decide whether a pool has a tarry goo build-up or scum.

Question Action
H1 Is the goo on a vinyl liner pool? Yes: Question H2.
No: Treatment H1.
H2 Is the goo on the bottom and sides of the
pool?
Yes: Question H4.
No: Question H3.
H3 Is the goo at the waterline? Yes: Treatment H1.
No: Question H4.
H4 Is the vinyl liner in its first or second season
and/or has this pool been opened for the
season recently?
Yes: Treatment H2.
No: Treatment H1.

 

Treatment H1 - Waterline Scum:

Treatment H2 - Pool Goo or Tar:

 

I. Disappearance of Cyanuric Acid

The following questions should be asked to determine which of five mechanisms could be the cause of cyanuric acid disappearance. Irrespective of the mechanism, the corrective action is generally the same.

Question Action
I1 Has Stabiliser 100 or Salt Pool Stabiliser
been added to the pool recently?
Yes: Question I2.
No: Treat with Stabiliser 100 or Salt Pool
Stabiliser. Monitor stabiliser levels to ensure no
further disappearance.
I2
Was the pump run continuously and not
backwashed for 24 - 48 hours after the
addition of Stabiliser 100 or Salt Pool
Stabiliser?
Yes: Question I3.
No: The stabiliser has not had time to completely
dissolve and has been largely removed by the
pool's filter. Reapply Stabiliser 100 or Salt Pool
Stabiliser, ensuring that the pump runs for 24 - 48
hours. Do not backwash during this time. Monitor
stabiliser levels to ensure no further
disappearance.
I3 Did you neutralise the chlorine in the water
sample before you added the cyanuric acid
test tablet?
Yes: Question I4.
No: Repeat the cyanuric acid test, adding 2 drops
of No. 4 Chlorine Neutraliser before adding the
test tablet. In cases where the chlorine level is
high (> 3.0 ppm), add 1 additional drop of Chlorine
Neutraliser for every additional 2.0 ppm of
chlorine. If cyanuric acid still reads zero, go to
Question I4.
I4 Are the cyanuric acid test tablets relatively
new (not more than a year old)?

Yes: Cyanuric acid level is low. Go to Question I5.

No: Obtain fresher tablets and repeat test. If
cyanuric acid still reads zero, go to Question I5.

I5 Was the pool just opened for the season
when you noticed that the cyanuric acid level
had dropped?
Yes: Clean filter with Filter Brite, re-balance pool
and shock with Burn Out Extreme (120 grams
per 10,000 litres). Monitor stabiliser levels to
ensure no further disappearance.
No: Question I6.
I6 Has the pool had an algae or bacteria (slime)
problem recently?
Yes: Clean filter with Filter Brite, re-balance pool
and shock with Burn Out Extreme (120 grams
per 10,000 litres). Monitor stabiliser levels to
ensure no further disappearance.
No: Question I7.
I7 Has the cyanuric acid disappeared in a short
period of time (around 2 to 3 weeks)?
Yes: Treat with Stabiliser 100 or Salt Pool
Stabiliser. Monitor stabiliser levels to ensure no
further disappearance.
No: Question I8.
I8 Has the pool had a chlorine demand problem
recently?
Yes: Clean filter with Filter Brite, re-balance pool
and shock with Burn Out Extreme (120 grams
per 10,000 litres). Monitor stabiliser levels to
ensure no further disappearance.
No: Question I9.
I9 Was the chlorine level too high for any length
of time?
Yes: Treat with Stabiliser 100 or Salt Pool
Stabiliser. Monitor stabiliser levels to ensure no
further disappearance.
No: Question I10.
I10 Has the pH been high (above 7.6) for any
length of time in the past couple of weeks?
Yes: Treat with Stabiliser 100 or Salt Pool
Stabiliser. Monitor stabiliser levels to ensure no
further disappearance.
No: Question I11.
I11 Is the pool on a non-stabilised chlorination
program (ie. salt chlorination, liquid chlorine,
cal hypo or lithium hypochlorite)?
Yes: Convert pool to a program involving either
Power Chlor, Power Tabs or Smart Sticks
(Authorised Dealers only).
No: Question I12.
I12 Does the pool have, or had, a slow leak as
indicated by having to add more than the
usual volume of make-up water?
Yes: If pool is leaking then it must be repaired
before making any water balance adjustments and
re-stabilising the pool.
No: Reason for stabiliser loss could not be
ascertained. Treat pool with Stabiliser 100 or
Salt Pool Stabiliser, and monitor stabiliser levels
to ensure no further disappearance.

 

J. Purple Deposits Around Skimmer or at Waterline

This problem tends to show up in pools with very high stabiliser levels and at least 1 ppm of copper.

Question Action
J1 Are there any plants with purple foliage
and/or flowers near the pool?
Yes: Skim the material off the water and wipe
surfaces, using Off The Wall if necessary.
No: Question J2.
J2 Is there any copper (above 0.1 ppm) in the
pool?
Yes: Question J3.
No: There can be copper present in a pool even
though no copper has been detected in the water.
All this means is that the copper has completely
precipitated out of solution. Go to Question J3.
J3 Is the cyanuric acid level in excess of 200
ppm?
Yes: See comments below regarding testing. The
cyanuric acid level must be lowered by partially
draining and refilling the pool with fresh water.
Remove any deposits using Treatment J1.
No: Question J4.
J4 Does the pool have a very high chlorine
residual (> 10 ppm)?
Yes: Lower the chlorine residual using Chem Out;
18 grams per 10,000 litres will reduce the chlorine
residual by 1 ppm. Once chlorine level is less
than 5 ppm, remove the purple deposit using
Treatment J1.
No: Question J5.
J5 Does the pool use Power Chlor or Smart
Sticks?
Yes: More than likely, the deposit will be confined
to the area around the skimmer. Remove the
deposit using Treatment J1.
No: The source is unknown but may be fallout
from some process in the vicinity of the pool.
Skim the material off the water and wipe surfaces,
using Off The Wall if necessary.

Treatment J1 - Purple Deposits:

Testing Cyanuric Acid Concentrations in Excess of 100 ppm Using the Wet-Lab

K. Products Compatible with Ionisers, Ozonators and Salt-Chlorinators


The above information is supplied by Bio-Lab and represents its best interpretation of available technical information at the time of preparation. The sole purpose is to supply factual information to Bio-Lab customers. It is not to be taken out of context nor used as support for any other claim not made herein.