Get Rid of Hot Tub Scum

hot tub

Scum lines are one of the more unpleasant and disgusting problems that occur in hot tubs. It can manifest itself as a greasy green build up along the liner or a gray, brownish layer of filth. No matter how it looks or where it came from, you just want it gone. Here’s a guide to help you diagnose and get rid of hot tub scum.

Keep Water Clean

The first line of defense is maintaining proper chemistry levels, regularly replacing your hot tub water, and properly sanitizing the liner itself. This means emptying and refilling your hot tub every 60-90 days and using a cleaner while it’s empty to help keep everything as hygienic as possible. If it’s a mild scum problem, you may use a wipe or cleaning system along the water line without having to empty it entirely.

Shower First

One of the biggest sources of junky scum comes from bathers themselves. If you’re having continuous buildup problems in your spa, make sure you take a shower before you enter the soothing water of your hot tub. Want to know all of the stuff you collect on your skin and hair that can gunk up your water? Oil, dead skin cells, lotions, creams, deodorant, and hair products can all contribute to scummy H2O. If you take a few minutes to shower off before hand, you can get all that stuff down the drain instead of circulating in your spa water (and collecting on your liner).


Make sure you’re doing a regular shock treatment in your hot tub, particularly if you are heavy users of your hot tub. If scum constantly presents itself in your water, you might need to boost your sanitizer levels and weekly shock treatments are a great way to do that.

You should also maintain a regular cleaning schedule which includes draining and scrubbing down your acrylic liner with a non-foaming cleaner before refilling with new water.

Assessing the Problem

Green Scum

If your scum is green, this is usually a sign that there is some kind of metal in your water. Copper, magnesium, or some other dissolved metal in the water often reacts with bromine and can leave behind a green residue. To help eliminate the problem? Try a pre-filter so that your fill water will have as little extra metal in it as possible and you won’t have to do as much post-fill adjusting.

Blue/Green Scum

If your scum has a bluish green tint to it, there’s a chance that there’s a problem with your filters. It could be clogged, torn, or just worn out. Remember: standard paper filters should be replaced entirely every 1 ½-2 years, depending on how well they’re maintained. Filters should be getting sprayed off and cleaned once a month to help ensure their effectiveness so that the water stays properly sanitized and has proper circulation.

Brown Scum

If you have a brown/grey color scum presenting itself, it could be a mineral like iron reacting in your water. This could also be an indicator that your pH level is a little high and you should try using a pH decreaser. Try to keep it at the lower end of 7.2-7.4 for a few months.

Extra Treatment

There are a few different products you can add regularly to your water to help keep it scum-free.

  • Any water clarifier (Spa Perfect, Leisure Time Enzyme, Spa Pure Clarifier)
  • Stain and scale preventer
  • Scum Away or any kind of scum digester or absorber
  • You can also buy floating sponges like the Swimline GooGetter or the Scumball that will absorb lotions and oils in the water.

To sum up, make sure you clean your spa regularly and maintain your sanitizer levels, change out the water completely every two to three months, and clean the liner thoroughly between emptying and filling. If you have a chronic problem, don’t be afraid to add some extra clarifiers or preventers to help treat it properly.

Leave a Reply