Chlorine Granules are a powder form of chlorine (Sodium Dichlor) and they can be added directly to your hot tub water. Chlorine Tablets for hot tubs (Trichlor) are the size of a 50p piece and usually float in a dispenser or an in-line feeder.
The most significant benefit of using chlorine tablets for your pool is its longer-term nature compared to granules. Once you get the right dosage, you shouldn't have to add another chlorine treatment for at least a few days.
Liquid chlorine and granular shock have the same active chemical that sanitizes your pool, what changes is the strength and the way you use it. Liquid chlorine is less costly, unstabilized and comes in liquid form. Granular shock is stabilized and comes in a solid form that dissolves in your pool.
Never add Granular Chlorine to Chlorinator. Using the pucks can be a little tricky in the beginning. Again, without getting too technical, it is important not to overuse pucks. Having pucks dissolve too quickly can cause long-term problems with water chemistry, and this, regardless of your pool size.
The method to add dry, granular chlorine to a swimming pool is relatively straightforward. You just need to measure the chemical, dissolve it in a bucket or similar container, and add the mixture around the perimeter. Take care never to add chlorine directly to the skimmer.
Calcium Hypochlorite (Granular Chlorine)
It's also one of the strongest shock treatments, coming with 68% calcium hypochlorite and is recommended for use in your pool only to kill algae when there is a breakout—and not for regular or daily chlorination of your pool to maintain free chlorine levels.
Chlorine granules, meanwhile, are simply scattered over a pool. Their combination of a smaller consistency and lower concentration makes them much more suitable for this purpose than chlorine tablets, as they dissolve more easily. This, in turn, enables them to fight pool bacteria much more quickly as well.
Do NOT use chlorine granules in a floater or feeder. When you're adding granules, broadcast them evenly over a wide area in the deepest part of the pool – NOT in the skimmer.
Not all Chlorine is Alike. Although we do not recommend packaged chlorine as a primary sanitizer in the hot water of spas, one type Dichlor Granular Chlorine is very good for occasional shocking and is a quick-dissolving form.
Granular chlorine can be applied by broadcasting over the pool or adding it to the skimmer. Dichlor chlorine is small grained and quickly dissolves, so it doesn't need to be dissolved in water before adding to the skimmer.
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.
Typically, a 3-inch pool chlorine tablet is designed to chlorinate from 7,500 to 10,000 gallons of water per week, meaning it'll take seven days to dissolve. If you have a 30,000-gallon pool, you'll need to place three 3-inch pool chlorine tablets in a chlorinator or floater.
It Should Not Be Done Together
This is because when you mix chlorine and algaecide together, it renders both of them useless. Hence, you should first shock the pool and wait for the chlorine levels to fall below 5 PPM. Only then should you introduce algaecide to get the best results.
Place one tablet in the skimmer basket per 45.450 litres (10,000 gallons) and adjust tablet numbers as necessary to take account of your water flow to achieve 1 - 3 mg/I (ppm) relatively consistently.
Verdict: For most Lay‑Z‑Spa users multifunctional tablets are an excellent way to maintain healthy chlorine levels, however, when shock dosing or setting up your spa chlorine granules can be more useful as the chlorine level can be raised more rapidly.
The shortage is due to increased demand for pool supplies during the pandemic and a chemical fire at a BioLab facility in Louisiana after Hurricane Laura that knocked out one of the country's three main chlorine manufacturers.
Dichlor is perhaps the most “best of all worlds” chlorine sanitizer. It is typically found in concentrations of 60-65%, which is comparable to cal-hypo. It is a powder sanitizer, which makes it easier to spread or broadcast around the pool than chlorine tablets.
The best rule of thumb for pool owners trying to estimate how many tablets to add is this: Add one tablet for every 5,000 gallons of water and always round up. For example, if your pool has 21,000 gallons of water, add five tablets per week. If it has 8,000 gallons, use two tablets.
For every person who uses the pool each day, you will require a further 10 grams of chlorine. Example – A 50,000 litre pool will require up to 200 grams of chlorine and if 5 people use the pool a further 50 grams of chlorine is required = total of 250 grams per day.
The cold water, anything below 65°, has an impact on the ability of the chemicals to dissolve properly. I would recommend using liquid chlorine if you have to shock in lower temperatures. You can dissolve granular shock in warm water. Perhaps it will work if you completely dissolve it before adding it to the pool.
Small Intex pools under 12′ in diameter should use 2-4 of the 1″ tablets in a chlorine floater. In addition to everyday chlorination of your Intex pool, you may have heard of shocking the pool. This refers to raising the chlorine level above 10 ppm by adding a granular chlorine powder, also known as pool shock.
Granular chlorine, also known as calcium hypochlorite, is a type of dry chlorine primarily used to clean swimming pools. It is one of two forms of solid chlorine, with the other form of solid chlorine being chlorine tablets.
Common unscented household bleach (sodium hypochlorite) works well to shock a pool.
Depending on how much you have added and the size of your pool, it is generally safe to wait about 4 hours after adding liquid chlorine or until levels reach 5 ppm or lower.