Outdoor Spa Bath Facts from Oasis Spas Australia

Filtration Costs

Some spa brands promote energy efficient filtration pumps but if they run 24 hours a day they will actually cost you more to run. One brand uses a multi-speed pump for filtration which can save a small amount of money, but these pumps offer a less powerful massage and the technology is new and complicated.

Pump Sizes

Be aware that some manufacturers mislead their customers into thinking that they are getting a larger pump on their front yard or backyard outdoor spa. The truth is that a 4.8 BHP (brake horse power) pump is exactly the same as a 3 HP pump and a 3.6 BHP pump is in fact only a 2 HP pump.

Running Costs

Be aware that many manufacturers only include filtration costs when discussing overall running costs, but this is only true if you are not heating your hot tub!

Other manufacturers promote running costs based on incorrect power costs and the use of a smart meter and heat pump (which won’t apply to most spas). If specific running costs are claimed, ask what these figures are based on.

Heating Costs

Comparing different electrically heated spas, the only thing that will effect running costs is the size of the heater (larger heaters will heat the water quicker, allowing the pump to turn off sooner).

Unless you use a heat pump, the most important factor in reducing running costs is how well the spa is insulated.

Insulation and Energy Efficiency “Star Ratings”

At this point in time, no independent body is able to allocate “efficiency ratings” to individual spa brands. Where star ratings are being used, they’re simply being “made up” by manufacturers who are giving themselves

“8 star” ratings with only basic insulation systems.

If you want to understand how efficient a front yard or backyard outdoor spa bath is, look at the amount of and/or number of layers of insulation on the shell, the inside of the cabinet panels and the base.

Some companies claim that insulation on the shell is not necessary. This claim is refuted by 99.99% of spa manufacturers as this form of insulation is in fact the most important way to stop heat loss.

The size of the gap between the shell and cabinet is also important as hot air escapes and cold air can enter through this gap.

UV “Sterilisers”

While these are now being used by a handful of companies around the world, this form of water treatment is not successful in spas due to the inadequate size of the UV sterilisers being used and the “by-pass” plumbing system they’re fitted with. Regarding this type of system, the major supplier advised us… Most water does not pass the UV chamber and the sterilisation will not be good enough so we do not recommend this by-pass unit

These systems can also be dangerous as when the bulb breaks, electricity will pass into the water. The bulbs will also need to be replaced regularly and your filtration costs will increase dramatically to get any noticeable benefits. If these small “by-pass” systems were effective, safe and reliable, all spa manufacturers would be using them, not just a few companies who are using this concept as nothing more than a marketing gimmick. A correctly sized “inline” system could work, but these are too large and very expensive.

Ozone

Ozone is a proven method of treating outdoor spa bath water. It is used in over 95% of hot tubs, improving water quality and reducing chemical use. However it is not legal or possible for an ozone system to replace all of your sanitation requirements – an approved sanitiser must still be used.

Ozone is not harmful to your health while you are in your spa as all the control systems are designed to turn the ozone system off when it is in use.

It is, however, very important that your ozone system has some form of mixing or (de-gas) chamber to make sure that the ozone gas has the longest “reaction time” with the water and to ensure any excess ozone gases are not released into the water (which will damage your cover and headrests).

“Salt Water” Spas

Salt (NaCl) can only be used to sanitise water when it is transformed (by a salt chlorinator) into chlorine. As such, “salt spas” are actually chlorinated hot tubs. People generally don’t like chlorine but an even bigger problem lies in its unsuitability to hot water.

Firstly, chlorine is very corrosive and will damage your heater element. More importantly, it is virtually useless in hot water, which has serious health consequences. If you insist on a salt/chlorine based sanitiser, remember that you will also need to add “bromine” to maintain safe water quality.

Spas with TV’s

Built-in TV’s in spas have proven to be quite appealing but if you talk to any hot tub repair technician they will tell you that the average in-spa TV is lucky to last more than a year and the cost to replace or repair them is very high. The fact is that moisture, metal and electronics don’t mix and the mechanisms used to raise and lower the TV are prone to problems. They also take up valuable room inside your outdoor spa. These facts have meant that most major brands no longer offer TV’s and as a potential owner you have to decide if you are prepared to pay to have the TV repaired many times over its life.

Most retailers recommend that if you want to watch TV in your spa bath, a better option is a wall mounted, big screen TV near the outdoor spa that will cost you a fraction of the price and can be easily serviced.

Heat Pumps

Heat pumps are the best way to reduce spa running costs. Only hot tubs with a “Spa Net” brand control system and heat pump can be run as an integrated system, where your heat pump is connected to the control system and is controlled through your touch pad. This system also allows you to use your heat pump in “reverse cycle” to cool down the water in summer.

The only other ways to connect a heat pump is by 1) using a separate power supply and an additional filtration pump and plumbing system or 2) power the heat pump from the electric spa heater, which will damage the heat pump over time as it can’t shut down properly after each use (outdoor spas with 2 speed pumps can’t be run like this). Either way, you cannot cool the water with either of these alternatives.

Jet Quality

It is important to find out what type of plastic has been used to make the spa jets as most jet manufacturers use a soft plastic that becomes damaged and brittle with chemical use. The back of the jets disintegrate and the clips that hold the jets break off, meaning the jets have to be replaced regularly.

The material used to produce the best quality jets is PVC which is almost impossible to damage. These jets do not have clips (they screw in) which makes them easier to swap and remove and have a bearing-less design which means they don’t need cleaning and won’t get clogged and stop spinning.

Micro Filters

These filters are offered by some brands and can improve water quality as they filter much finer particles from the water (1-5 micron instead of 50 micron). They have the added advantage of being impregnated with silver ions which help stop bacteria multiplying.

However, you must replace the filters every month or so as the fine membrane becomes easily clogged, at which point filtration reduces and your pump can be damaged. If you don’t mind the extra cost to replace them regularly they are not a bad choice for time poor spa owners.