Troubleshooting & Miscellaneous Mathematical Formulas

Here are some commonly used mathematical formulas that are helpful in the pool and hot tub industry for calculating pool volumes and chemical dosages among other things.

Circle Area = Pi (3.14) x Radius²

Circumference = Pi (3.14) x Diameter or 2 (Pi) 3.14 x Radius

Diameter = C / Pi (3.14)

Radius = C / 2 Pi (3.14)

Rectangle or Square Area = length x width

Triangle Area = 1/2 base x height

Cube or Rectangular Box Volume = length x width x height

Standard/Metric Conversions

inch x 25.4 = millimeter            millimeter x .0394 = inch
foot x .3048 = meter            meter x 3.2808 = foot
yard x .9144 = meter             meter x 1.0936 = yard
mile x 1.6093 = kilometer          kilometer x .6214 = mile
quart x .9463 = liter               liter x 1.0567 =  quart
ounce x 28.3495 = gram         gram x .0353 = ounce
pound x .4536 = kilogram               kilogram x 2.2046 = pound
degrees F x 5/9 = degrees C        degrees C x 9/5 +32 = degrees F

Units of Capacity

1 Gallon = 4 Quarts = 8 Pints = 16 Cups = 128 Oz
1 Quart = 2 Pints = 4 Cups = 32 Oz
1 Pint = 2 Cups = 16 Oz
1 Cup = 8 Oz. 

Troubleshooting pool and hot tub problems. 

Here are answers to some commonly asked problems related to swimming pools and swimming pool equipment.

I have sand going into my pool when I run my filter.

The most common problem is a broken “lateral” in the bottom of the filter. In order to find the problem, you need to remove all of the sand from the filter and inspect the components inside the filter. If any of the “laterals” are cracked, or if the center “standpipe” is cracked, it will allow sand to blow back into the pool. The “lateral” usually unscrew from the base of the “standpipe” for easy replacement. Make sure you order the proper length lateral for your filter.

I have earth going into my pool when I run the filter.

The most common problem is a torn or damaged “finger”, grid” or “element”. The earth is put into the filter through the skimmer. It is then trapped in the filter when it pushed against the “finger”, “grid” , or “element”. If the element is cracked or torn, instead of trapping the earth in the filter, it goes back into the pool. To find the problem, you need to visually inspect the internal components of the filter and look for holes in the nylon grid material. If you have a Hayward Perflex filter, make sure all of the bolts and nuts are in place, and that the plates that hold the “fingers” are not cracked. A missing bolt or cracked plate will allow the earth to pass through the filter and return to the pool.

I have a sand filter and have dirt going back into my pool when I filter. 

The small dirt particles are passing through the sand in the  filter. You can solve the problem by changing the sand (if it has been in the filter over a year for aboveground filters, or over 5 years for an inground filter); or utilize a clarifier or sand aid product to help trap the small dirt particles.

My vacuum head keeps sticking to the bottom of the pool.

The brushes on the bottom of the vacuum head are worn. When you vacuum, the suction is causing the brushes to collapse and the vacuum head then sucks to the liner. You should replace either the vacuum head or the brushes.

My filter is very noisy. 

The noise is coming from the motor. The bearings in the motor are worn out. You can either have the bearings replaced by a motor shop, or you can replace the whole “motor/pump” of the filter.

When I turn my filter on, my circuit breaker goes off.

The bearings in the motor, or the windings in the motor are bad. The motor needs to be replaced. You can try to run the motor on a different electrical outlet to rule out a problem with your electrical wiring. If the problem continues, replace the motor.

My heater will not turn on.

Try to backwash the filter and then restart the heater. The heater has a “pressure switch” (a safety device) which will not allow the heater to operate if there is not adequate water flow through it. If the problem persists, call a qualified technician for service. One or more of the components may be defective - thermostat, hi limit switches, on/off switch, etc..

My kids hair turns green when swimming in our pool.

The presence of copper in water will cause light colored hair to turn green. To remove the copper, add a mineral remover to the water. Extremely high levels of copper can cause sever staining of the pool liner. The source of copper can be from the use of algaecide which uses copper, a winterizing kit which uses copper, or from a deteriorating heater core - caused by low water pH

My pump will not prime.

There are many possible causes. Check each of the following.

              1). No water in the strainer pot.
              2). Strainer pot lid not on tight.
              3). Damaged strainer pot lid o-ring.
              4). Water level in the pool is below the skimmer.
              5). Strainer basket or skimmer basket is clogged.
              6). Closed valve in the plumbing system.
              7). Pump is on low speed (two speed pump units only).
              8). Air leak(s) in the suction line.

I have low water flow, and the pressure on my filter is high.

There are two possible causes, (1). the filter needs backwashing, or (2). there is a restriction in the return line.

I have low water flow and low pressure on my filter.

           Check the following:

              1). Strainer basket or skimmer basket is clogged.
              2). The impeller is clogged.
              3). Air leak in the suction line
              4). Restriction in the suction line.

My motor will not turn on.

             Check the following:

               1). Power switch is off.
               2). Circuit breaker has tripped
               3). Timer circuit is in off mode.
               4). Motor shaft is locked because of bad bearings
               5). Impeller is locked by debris.