Replacing Hot Tub Covers

When is it time to replace a hot tub cover?

While there is no set point at which a cover should be replaced, most covers will need to be replaced after 5-7 years. Over time, hot tub covers will become saturated with water, becoming heavier and heavier. Eventually they will either become too heavy to lift or the seam between the two sides of the cover will tear and the cover will split in two. Covers can also start to "cup" if they are subjected to  heavy loads, like an excessive amount of snow or ice.

Covers should be replaced as soon as you notice either happen. Foam insulates by trapping

A badly cupped hot tub cover. Any cover
that develops puddles like this is cupped and
should be replaced.

warm air in the bubbles of the foam. As  covers become saturated and those bubbles fill with water the cover will lose it's ability to effectively insulate and can cause your monthly energy bill to increase. A cupped hot tub cover will also cause an increase in energy costs as it causes the corners of the cover to lift up, breaking the seal around the edge and allowing the heat to escape.

What to look for when buying a new cover

The first thing to do when looking for a new hot tub cover is to look at a sample of the covers the retailer provides (or at least a sample of the vinyl). Check the thickness of the vinyl, the thickness of the cover, and the quality of the stitching as these are usually the first things that are neglected on cheaper covers.

 If your hot tub has a cover lifter we've found that a 4"-3" tapered cover tends to sit best, and last the longest. Thicker covers will tend to put added stress on the seam of the cover when sitting on the arm of the cover lifter. As it gets saturated (and heavier) it will rip on that seam. The added insulating ability of the thicker cover is therefore negated by having to buy a new cover sooner.

Most retailers will also offer different "foam densities". The higher the density of the foam, the better the insulating value of the foam, and the stronger the cover will be. While the added insulating value of higher foam densities is not very significant, the added strength can be a big plus if you experience heavy snowfalls, or if there is a chance of pets or children climbing on the cover (still not recommended).

Some common extras you can get for covers are a full foam sealer (also known as a full hinge seal or centre seal), aluminum backing for the foam to help strengthen the centre of the cover (and help prevent cupping under heavy loads), and a vapour barrier wrap around the foam.

Thermal images of a cover with and
without a full foam sealer. Without the
full foam sealer there  is a 19 degree
difference, with it less than 1 degree!

 A full foam sealer is a piece of foam that fills and insulates the area between the two sides of the cover. Without it the cover will have a 1" gap that is only insulated by the cover's vinyl skin when it is closed. Most covers will come standard with only small (4") pieces of foam on either end of the cover. These are useful for preventing evaporation, but do not offer much in the way of insulation.

Wrapping the foam with a plastic vapour barrier will help slow down the rate at which water saturates the foam, extending the life of the cover. They will typically range in thickness from 2ml to 10ml, the thicker the better.

Lastly, watch out for some online retailers that will advertise low prices for their basic covers. When those retailer's covers are priced with features that are comparable to what other retailers provide as standard they will often end up being very similar priced. By buying a cover online you may also be losing out on free delivery or disposal of your old cover, and if there is a problem with the cover you would have to worry about return shipping and dealing with notoriously bad online service.

Extending the life of your hot tub cover

We'll close out this entry with a few tips for how to extend the life of your current hot tub cover.

•  Keep the cover clipped in to prevent it being potentially carried off and damaged by high winds.
•  Avoid resting anything heavy on your cover, remove any heavy loads of snow or ice in the winter. When removing snow off of a cover don't use a shovel. Shovel blades can catch on the cover and tear the vinyl, leading to the cover rapidly becoming waterlogged. Brushes used for cars work well.
• Leave your cover fully open for at least 30 minutes after shocking your hot tub. After you shock the hot tub, strong chemical vapours are released that can harm the underside of the cover.
•  If you don't have a cover lifter, use the cover's handles when moving the cover on and off the hot tub. This will reduce wear on the stitched seams of the cover and prevent them tearing from improper handling.
• Clean your cover using a UV protecting spray at least twice a year to help reduce the harmful effects of the sun on the vinyl finish and stitching.

Biofilm -What It Is and How It Affects Your Hot Tub

What Is Biofilm?

Biofilm is any group of bacteria and other micro-organisms that stick themselves to a surface which is in regular contact with water. These micro-organisms will cover themselves in a protective layer of slime that is resistant to disinfectants (like chlorine or bromine). Biofilm can harbour harmful bacteria like Legionella (Legionnaire's Disease), Pseudomonas Aeruginosas, Mycobacterium Fortuitum and E-Coli. It forms naturally under most conditions but thrives in dark, warm (>90°F), water rich environments. If the surface that biofilm is on dries out it will not die but rather it will go into a dormant state, reactivating once it comes in contact with water again.

How Does Biofilm Affect My Hot Tub?

As mentioned in the last section biofilm forms on any surface that is in water, or that is in consistent contact with water and thrives in warm, dark areas. The plumbing and filtration system in hot tubs provide an ideal environment for biofilms to grow. Add in all of the organics that humans introduce in the water like lotions, soaps, antiperspirants, and sweat and you've got a perfect environment for biofilms to grow. Because of this, even relatively new hot tub (less than a year old) can experience problems with biofilm.

Biofilm will greatly decrease your sanitizer's (chlorine/bromine) effectiveness in keeping your water bacteria free as the residual in the water is constantly being used up trying to get rid of the biofilm. You may also notice it as a visible ring at the waterline or discolouration on your filter.

How Can I Get Rid of Biofilm?

A hot tub with plumbing cleaner running through
it.The dicoloured foam is biofilm that has been
lifted off the surface of the plumbing.

Biofilm growing on the shell of the hot tub (usually at the waterline) can typically be wiped off with disinfecting wipes. Biofilm growth on filters and in the plumbing can be more difficult to remove however. As previously mentioned simply draining the hot tub and waiting for the plumbing or filter to dry out will not kill biofilm, just put in a dormant state. Once you refill the hot tub, or re-wet the filters, it will reactive itself and continue to grow.

In order to get rid of existing biofilm in your plumbing you will need to add a pipe cleaning product, typically right before draining. The cleaner is added with the jets running for a few cycles to allow it to properly circulate through the entire plumbing system. The hot tub is then drained and re-filled. To clean your filters properly soak them in a chemical cleaner made specifically for cleaning hot tub filters for a few hours or overnight.

How Can I Prevent Biofilm From Returning?

Adding AquaFinesse weekly will keep
biofilm from forming and will even
break down existing biofilm.

Once you've removed the biofilm from your hot tub you will want to keep it out. Enzyme based products like Natural Chemistry's Spa Perfect or Eco One's Spa Monthly can be added weekly or monthly to break down oils and other contaminants. These products rely on natural enzymes to break down the protective slime layer that covers the bacteria and will help to slow the formation of biofilm but won't completely stop it. Plumbing cleaners should still be used at least once a year to clean out the hot tub's plumbing and the filters should be chemically cleaned 3-4 times a year to rid them of biofilm.

While not cheap, we have found using AquaFinesse weekly to be the best way to keep biofilm out of hot tubs. It can even break down existing biofilm, allowing you to treat your plumbing without having to drain and refill the hot tub.

If you have any questions about biofilm or any other water care issue call our certified water care specialists at 905-666-5333. Like us on Facebook (www.facebook.com/TheSpaShoppe) or follow us on Twitter (@thespashoppe) to get notified when new blog entries are posted.