Testing
Test strips eliminate your excuses! Testing is your most important task because you can't tell just by looking! You've got to know for sure if you have enough sanitizer OR if your pH is low. Water balance is essential or your water will eat up your equipment. With test strips you just dip and compare colors Couldn't be easier! 3 in one strips give you bromine or chlorine residual, pH and total alkalinity readings. With those three tests you will know all you need, in most cases, to create the safe, clear, sparkling water you desire! There are also more advanced test kits available. Kits are available that test for calcium hardness, the presence of metals, the presence of sequestering agents and many different factors, but the big three are right here!

Sanitizing
Keep algae, bacteria and viruses from growing in hot tub and spa water. It is not safe to use a spa that has unreadable sanitizer levels. pH refers to how acidic (LOW pH) or basic (HIGH pH) the water is. It needs to be just a little above neutral. Perfect spa and hot tub pH is 7.5... that's also the ph of your body so at that pH the water is chemically in sync with your body's pH. Water doesn't burn eyes and is kind to your skin etc. As it drops to 7.4 then 7.3 it becomes more acidic and begins to be corrosive to metals (heater elements, pump seals, heat exchangers and plaster), if you have a plaster spa. Once the ph drops below 7.0 and stays for a while - it has done some damage. It may take a while to manifest itself but it will! High pH is also a problem. It causes scale and stains to form.
Total alkalinity... The buffering ability of the water. Alkalines in the water " buffer" or protect the pH from change.

Sanitizers commonly used for hot tubs and spas are bromine and chlorine. bromine and chlorine are in the chemical family known as halogens. They are oxidizers. They burn up anything organic they come in contact with. They have a tendency to combine with nitrogens and ammonias which are bather by products. This reduces their effect and we must regularly rearrange this little chemical bonding orgy by shocking, adding a bunch more single atoms electrons and stuff to tear them assunder.

Ozone is a gas produced by a piece of equipment called an OZONATOR. Ozone is an oxidizer like chlorine and it's powerful too, but it has no residual effect. It does not linger in your water on patrol. It reduces your need for chlorine or bromine but when using ozone to treat your spa you still need some chlorine based SANITIZER to have complete protection! In a bromine treated spa ozone does a great job of keeping bromine away from nitrogen and ammonia. Shocking is reduced but the need for residual sanitizer remains. You won't need alot but you will need some. Nature2 reduces your need for chlorine or bromine by using natural elements to trap viruses and kill algae. It is becoming popular as a sanitizer assistant! It does not work with bromine however. Spas treated with bromine must be drained and refilled first.

Recommended

Not Recommended

Sodium Dichlor	(65% available chlorine, pH 7)	Calcium hypochlorite	(65% available chlorine, pH 13)
Lithium Hypochlorite	(35% Available Chlorine, pH 8)	Trichlor Chlorine Tablets	(80% avail Chlorine, pH 2)
Bromine Tablets	(65% available Bromine, pH 2)	Liquid Chlorine	(14% available , pH 14)

Raising sanitizer levels is shocking
The quickest way to raise sanitizer levels is to shock with a chlorine based shock. This is NOT harmful even in a spa treated with bromine. Dichlor and lithium are granular chlorines with close to neutral pH. They are completely soluble. The amount to add would be approximately a short cap full of lithium or a tablespoon or two of dichlor. A little more little less depending on the size of your spa and your water condition. You can always dissipate chlorine by running your spa and aerating it. If it looks crummy, or you've ignored it for awhile, lithium or dichlor will immediately correct any sanitizing problem lack of attention may have generated (algae, cloudy water, musty locker room smell!) A weekly shock would be in order for all bromine treated spas. I'd recommend it as well for spas using ozone or Nature2. That weekly treatment may be the only chlorine you'll have to add!
Lowering your chlorine
Oops, you meant to sprinkle it in but a big clump fell out. Don't despair! Just turn on your spa with the cover off and run it for awhile with the jets on and the blower on as well. Turbulence, sunlight and heat all decrease chlorine levels. If it's slightly high don't worry about it it will dissipate fairly quickly.

pH level and alkalinity level
Raising your pH is accomplished by feeding the alkalinity. If you use bicarb (baking soda) you will raise the alkalinity as well as the pH. They follow each other and using bicarb is a gentle way to effect a pH rise. Use 1/3 cup to raise 20ppm per 500gals. While you don't want to way over treat, like put 5 cups in at a time, over treating won't really hurt anything. If the spa shell becomes sand papery, your pH and alkalinity is too high! You'll need to drain your spa.

Lowering Your pH is accomplished by adding acid, pH Down. This will erode both the alkalinity and the pH. In some areas of the country water is extremely alkaline or hard and adding acid is necessary at fill. Most areas do not require lowering the pH. You only need to lower it if it tests above 8.0. If you misuse pH down (acid) it will eat up your equipment and your plaster!

When to drain
Hot tubs and spas need to be drained at least once per quarter. If you are really using it daily then possibly you might want to drain it even more often. Just remember, if you are suddenly having a hard time getting the chemicals to line up right - just drain it. Starting over is sometimes the best thing you can do. As we use the spa it builds up with TOTAL DISSOLVED SOLIDS that are too small to be filtered but can cause cloudy water and alot of foam. If this is happening a fresh fill will help the situation. If bromine smell is catching in your throat and the water from your jets looks like smoke - drain it. Shocking will help but not for long. Think about an ozonator and Nature2. Caution. Always turn your heater thermostat all the way down when draining. You always want to turn the heater on LAST after you power back up and only when you are sure the pump is primed and pumping!

Problem water
WELL....If you have well water with a high mineral content, you may need a stain and scale preventer. These products either sequester (cause to clump) or chelate (surround and protect) metals and minerals. They are extremely important at fill in some areas of the country and completely unnecessary in others. They should be used if needed and not used if not. If you know you have problem water they will be part of your regimen. Follow the instructions on the bottle.

Soft water
Try not to use soft water. Bypass your softener if you can. Soft water is aggressive and can cause problems with your equipment or plaster. If you must use it you'll need to add calcium back to it and toughen it up.