It will slightly raise your pH, so make sure you adjust pH while using it. As the name implies, it will also raise your calcium hardness levels in your pool slightly.
Cal-hypo shock: Use this if you have algae issues or if you want a powerful, weekly treatment. You will need to use this at night and wait at least 8 hours before swimming. Be careful using it in saltwater pools, since it can cause scale build-up in the saltwater generator by increasing your calcium hardness levels.
Calcium hardness should be kept at 250 ppm minimum. Once full, getting your pool to 250 ppm is important; from there if you're using calcium hypochlorite to add chlorine to your pool your calcium hardness will steadily increase. There is no real reason to lower your hardness.
If your calcium hardness is too low, you can increase it by adding calcium chloride into your pool water. This is very cheap to buy from your pool shop. Adding calcium to your pool will increase the calcium level right away.
Each pound of cal-hypo will add 5-7 ppm to Calcium Hardness levels. Vinyl pools benefit from non-chlorine shock, which won't bleach or fade vinyl liners, and also don't cloud the water or leave behind a dusty residue.
With low alkalinity, your pool's water becomes corrosive enough to damage equipment. Rainwater can also mess up the calcium hardness in your swimming pool. Since the rain has 0 ppm calcium hardness, it could lower the water hardness if your pool has soft water.
Calcium on the low and high end of the scales will eventually cause problems and when they do, be ready for some serious problems. Low calcium, as is often the case, will cause long-term serious damage especially to plaster, vinyl liners, grout in between tiles, metal rails, and even concrete decking around the pool.
A low hardness level can lead to corrosion of the pool surface, filter, heater, ladder, etc. Likewise, if the water is too soft(low calcium level) you are also more likely to experience problems with algae. A calcium hardness level that is too high can cause cloudy water and scaling (a white chalky appearance).
Calcium hardness must be actively managed—along with pH and total alkalinity—to keep water in proper chemical balance. Current industry standards call for maintaining calcium hardness in the ideal range of 200–400 ppm in pools and 150–250 ppm in spas.
The two are linked because as explained above, calcium hardness can cause PH to be hard to balance. If you have hard water in your hot tub, balancing the PH will also help prevent scale build-up as although hardness exists in the water, you are managing this correctly through PH.
Thankfully, it's easier to raise water hardness than lower it. Seek out a calcium hardness increaser. It sounds fancy, but this is usually a bucket of calcium chloride. Follow the directions and add the appropriate amount of calcium to get your water hardness back to safe levels.
No, baking soda does not increase calcium hardness. This is a common myth that exists in the pool industry. Adding baking soda when you don't need to can actually cause a whole host of problems later down the line.
The simple answer is yes, you can over shock a pool. This is when the chlorine level in the water becomes too high and can be harmful to swimmers. When you shock your pool, you are raising the chlorine level to 10 times its normal level. This is done to kill off any bacteria or algae that may be present in your pool.
If you put too much shock in the pool, simply wait it out. If you have a cover on your pool, take it off. The more sun that hits your water, the faster it will dissipate. Technically, if your free chlorine levels are holding up swimming UP TO your shock level, depending on your CYA, is safe.
Calcium hardness is sometimes overlooked when having testing done. This is an important step due to the fact that if levels are too high it can cause the calcium to fall out of solution and cloud the water.
Increases The Calcium Hardness
The rainwater will not directly increase the calcium hardiness or the dissolved solids in your pool. However, it will wash any dirt or minerals off your pool deck into the pool water. This may increase the calcium hardiness and affect your pool's total alkalinity levels.
Rainfall dilutes pool chemistry levels and lowers the readings for pH, alkalinity, hardness, stabilizer, and chlorine. Rainfall does not contain chlorine. As well, rainfall brings with it small amounts of contaminants that are washed into the pool.
How to Raise Hardness in a Pool. If your swimming pool doesn't have enough calcium, you can add a pool water hardness increaser to the water easily raises calcium levels. You can buy a bucket of granular hardness increaser at just about any swimming pool retailer.
After Adding Calcium Chloride to Raise Calcium Hardness
You should wait 2–4 hours (or one full cycle through the filter) to swim from the moment you use calcium chloride in your pool.
For vinyl pools, calcium should be between 150-250 ppm. A low level can result in foaming, which is unpleasant but shouldn't harm the liner. If calcium hardness goes above 400 ppm, you will likely see a white, flaky crust on the liner and pool equipment.
Is calcium hardness the same the total hardness? Calcium hardness is a measure of dissolved calcium in the water and total hardness is a measurement of the mineral content (calcium and magnesium) of the water.
Muriatic acid: Muriatic acid is known as a strong chemical. It can dissolve calcium deposits on pool tiles. It's important to use caution when handling this acid and to follow safety guidelines carefully. White vinegar: White vinegar is a more natural alternative to muriatic acid and can also dissolve calcium deposits.
How to Lower Calcium Hardness in Your Swimming Pool? There is really only one way to lower your pools high calcium hardness level and that is to partially or completely drain your hard pool water and replace it with fresh water.
Method 1: Drain & Replace Some Of The Water
Turn off the pool pump, then use a pump to drain a few inches of water. Replace this with water that contains little-to-no calcium minerals to bring down the overall hardness. Turn the pump back on.