Frequently Asked Questions
- What is the difference between chlorine and shock? Do I need to use both?
- I think I have algae. What do I do?
- My pool is cloudy. How do I clear it up?
- My water is green and does not improve with shock. How do I restore the water clarity?
- I have white powder at the bottom of my pool. What is it?
- Why do I need all these chemicals?
- My pool is stained. How do I clean it?
- How long after adding chemicals can I swim?
- How often should I run my filter? When should I clean or backwash it?
1) What is the difference between chlorine and shock? Do I need to use both?
Chlorine is a sanitizer, and (unless you use Baquacil products) is necessary for maintaining a clear and healthy pool. Shock is chlorine, in a high dose, meant to shock your pool and raise the chlorine level quickly. Chlorine tabs (placed in a chlorinator, floater, or skimmer basket) maintain a chlorine residual in the water.
You do need to use both tabs and shock. Without tabs, the chlorine shock will dissipate quickly out of the water; without shock, the chlorine level will not get high enough to fully sanitize the water. You should aim to keep the chlorine level at between 1 and 3 ppm.
We suggest shocking the pool every week to two weeks; with hot weather or increased use, you may need to shock more often. When tabs run out, replace them.
2) I think I have algae. What do I do?
Algae is typically a green growth, though it may also be mustard, black, or red. Sometimes it resembles a stain along the walls or floor; if you can brush it off, it is algae. If you can’t brush it off, it is probably a stain (see question 7). You cannot test for algae – if you see it in the water, or feel a slime along the liner, then you have it. Add a dose of algaecide, bring your chlorine level high by shocking, and run the filter continuously until the problem clears. The next day you should vacuum up the dead algae and backwash your filter.
Algae thrives in hot weather and in pools with low or no chlorine. Be dutiful in shocking every week to two weeks and add a maintenance dose of algaecide every other week to prevent further algae growth.
3) My pool is cloudy. How do I clear it up?
Water clarity issues typically stem from one of two causes: water imbalance or filtering problems. When your pool is cloudy, first check to see if it’s balanced properly. The easiest way is to bring a water sample to Splash Pool Supply. We will analyze your water within a couple minutes and set you up with any needed chemicals. You may also use test strips or a test kit at home. Common causes for cloudy water are low chlorine or low alkalinity levels. If the water is balanced, you could try a clarifier or flocculent; these products coagulate the particles in your water and drop them to the bottom so they can be vacuumed up. Run your filter until the water clears.
If treating the water does not solve the problem, you may have a filtering issue. Backwash your sand or DE filter; rinse the cartridge of your cartridge filter. If you have a sand filter, make sure to change the sand every 3 to 5 years. If you have a DE filter, try rinsing the fingers or grids with a filter solution and changing the DE powder.
If these tips still do not clear the water, you may have a metal problem (see question 4). The best thing to do is bring a water sample into the store and talk to a trained employee.
4) My water is green and does not improve with shock. How do I restore the water clarity?
Once you've ruled out algae (see question 2), It's time to think about metals. If the water is lime green, does not improve with shock, or gets worse after shocking, you may have metals in your water. The most common metals around here are copper and iron, especially common in well water. Chlorine oxidizes the metals, turning the water green, and sometimes staining the pool walls and floor. Bring a water sample to Splash Pool Supply and ask to be tested for metals. If they are present in your water, we will set you up with a product to remove them. You should also refrain from further shocking until the metal problem is resolved.
5) I have white powder at the bottom of my pool. What is it?
One possibility is that chemicals added incorrectly are sitting at the bottom of your pool. Did you remember to pre-mix the calcium balance in a pail of water? Did you add the water stabilizer through the skimmer? If not, these chemicals may not have dissolved correctly.
If you have a DE filter, however, it is likely that there is a tear in one of the fingers or grids inside the filter tank. DE powder escapes through these tears and is blown back into the pool. Remove the lid of the tank, wash off the fingers or grids, and carefully check for tears. You may need to replace a grid section, a few fingers, or even the whole tank. You may also have a crack or loose screws in the faceplate of the filter.
6) Why do I need:
Alkalinity helps to stabilize the pH; when the alkalinity is in range, the pH will fluctuate less. Low alkalinity will also cause hazy water. Alkalinity levels decrease with the acid rain; it is important to add Alkalinity Balance periodically throughout the summer to maintain a level between 100 and 150 ppm.
A low pH means that your pool is acidic. Acidic water can corrode metal fittings, filter systems, and especially heaters. The pH goes down with rain, so it is important to add pH Up periodically to maintain a level between 7.2 and 7.8. A pH that is too high or too low can also irritate your eyes. If your pH is too high, you may need to add some pH down.
Calcium Balance softens the water. Here in Connecticut, we tend to have rather hard water, so it is normal to need a good deal of Calcium Balance at the beginning of the season and after additions of fresh water to your pool. A proper level of calcium protects your liner and equipment from the harshness of the chemicals. If you own an inground gunite pool, adding calcium is essential; if the water is too hard, it will take minerals from the wall, thus deteriorating the walls and the paint. Calcium is also important to the clarity of your water.
Water Stabilizer acts as a sunblock for your pool, helping to hold chlorine in the water. Without a high enough stabilizer (cyanuric acid) level, the chlorine that you add to the water will quickly be sucked out by the sun. Add about 2 lbs. of stabilizer per 5,000 gallons of pool water. To add, pour stabilizer very slowly through your skimmer while the pump is running. Do not backwash the filter for 5 days; if you need to vacuum or backwash, do that first. The stabilizer will dissolve under pressure in your filter. Usually you will need to add another small dose of stabilizer towards the end of July.
Shock is liquid or granular chlorine. You should add one gallon (or one pound) of shock per 10,000 gallons of pool water every week to two weeks. During hot weather or frequent use, you may need to shock more frequently. Low chlorine levels often cause green or hazy water, so if your water looks a little cloudy and you haven't shocked in a while, adding shock is the first step. It is always best to shock the pool in the evening, when the sun if off the water. If not, the sun will suck it out as fast as you add it.
You should use chlorine tabs in conjunction with shock. The slow dissolve tabs hold a chlorine residual in the water. Tabs alone, however, will not provide sufficient chlorination for a pool.
7) My pool is stained. How do I clean it?
The most common cause of staining is metals in your water (see question 4). This is especially likely if you have well water or a heater. Bring a water sample to Splash Pool Supply and ask to be tested for metals. If they are present in your water, we will give you a product that removes metals and staining from pools. If the staining is due to other causes, our product Stain Out will quickly and easily remove it.
8) How long after adding chemicals can I swim?
Alkalinity Balance, pH up, pH down, Calcium Balance, Water Stabilizer, and clarifier are all swim-safe chemicals. Wait about 20 minutes, and you are free to swim. We suggest adding algaecide, Super Erace, and shock at night, after everyone is out of the pool. It is safe to swim again the next day.
9) How often should I run my filter? When should I clean or backwash it?
We recommend running the filter 8 to 10 hours a day, and running it continuously if the water is not clear. Make sure the filter is running when you add chemicals.
Backwash your sand filter once the pressure gauge reads 8 to 10 psi above normal (when it reaches 20 to 25 psi).
Bump your DE filter once the pressure gauge reads 8 to 10 psi above normal (when it reaches 20 to 25 psi). When pools are especially dirty, you’ll need to bump your DE filter more frequently. If the water pressure back to your pool does not improve, take apart the filter, clean the fingers or grids with a solution, and add fresh DE powder.
Replace the cartridge of a cartridge filter once a solution no longer adequately cleans it.