How To Deal With Spa Algae?

[billp333]

How to deal with spa algae.

Hi, I'm new, and I hope this is the right forum for this question.

I have a (gunite) spa, approx 2000 gallons. Since installation we've always had a huge problem with algae. It's so bad we haven't used it for a while, but I want to get it cleaned out again.

The spa is electrically heated, so we don't keep it that hot most of the time -- it's about $40 just to get it up to temp. So usually we keep it around 55 degrees in the winter, and just turn it up when we want to use it. In the summer it stays around 85 or so by itself. There is a 'stretch type' cover but no longer a thermal blanket, it made the algae worse. Bather load is very low -- 2 people for an hour, maybe 1-2 x per month max.

Filtration is via a 2 HP pump and a 90 sq foot filter which runs 24 hours a day. There is a Delzone ZO-900 ozonator.

Water chemistry is typically 100 ppm Alkalinity, 300 ppm Hardness. ph tends to creep up into the mid 8 range, so sometimes I add muriatic acid to get it back to the mid 7's.

We use bromine, with granules in the water and extra tablets in a floater.

Any thoughts on what I’m doing wrong?

Would an UV clarifier help? (I just added one to my outdoor ornamental fountain, and it helps a lot, but if using it with the spa I'd have to do a lot of plumbing, and I want to make sure before I delve into that).

I'd like to get it really cleaned out, powerwashed, and start from scratch, but want to make sure I have a better plan than what I've been doing so it just doesn't all start over again.

Thanks for any suggestions.

[Hillbilly Hot Tub]

How to deal with spa algae.

Hi, I'm new, and I hope this is the right forum for this question.

I have a (gunite) spa, approx 2000 gallons. Since installation we've always had a huge problem with algae. It's so bad we haven't used it for a while, but I want to get it cleaned out again.

The spa is electrically heated, so we don't keep it that hot most of the time -- it's about $40 just to get it up to temp. So usually we keep it around 55 degrees in the winter, and just turn it up when we want to use it. In the summer it stays around 85 or so by itself. There is a 'stretch type' cover but no longer a thermal blanket, it made the algae worse. Bather load is very low -- 2 people for an hour, maybe 1-2 x per month max.

Filtration is via a 2 HP pump and a 90 sq foot filter which runs 24 hours a day. There is a Delzone ZO-900 ozonator.

Water chemistry is typically 100 ppm Alkalinity, 300 ppm Hardness. ph tends to creep up into the mid 8 range, so sometimes I add muriatic acid to get it back to the mid 7's.

We use bromine, with granules in the water and extra tablets in a floater.

Any thoughts on what I’m doing wrong?

Would an UV clarifier help? (I just added one to my outdoor ornamental fountain, and it helps a lot, but if using it with the spa I'd have to do a lot of plumbing, and I want to make sure before I delve into that).

I'd like to get it really cleaned out, powerwashed, and start from scratch, but want to make sure I have a better plan than what I've been doing so it just doesn't all start over again.

Thanks for any suggestions.

Make sure to keep the Bromine levels up. Also, algea needs sunlight and phosphates to live. Have you tried algeacide and/or phosphate remover? These will cloud the water while killing the algea, but you can use a clarifier to help pick up the dead algea in your filter. Check out Sea Klear, the have great products for this issue.

[billp333]

Make sure to keep the Bromine levels up. Also, algea needs sunlight and phosphates to live. Have you tried algeacide and/or phosphate remover? These will cloud the water while killing the algea, but you can use a clarifier to help pick up the dead algea in your filter. Check out Sea Klear, the have great products for this issue.

Thanks for the info. I have used PhosFree, I assume that is a phosphate remover? I have used algeacide, but none I could fine are for spas, just pools, so I've tended to use this as a last resort. I've tried to keep the bromine up, and I guess I'm just suprised how fast it breaks down, I guess I'll have to put it in every day even with the tablets?

I'm just wondering why I get so much algae and most people don't seem to in spas?

[Hillbilly Hot Tub]

Thanks for the info. I have used PhosFree, I assume that is a phosphate remover? I have used algeacide, but none I could fine are for spas, just pools, so I've tended to use this as a last resort. I've tried to keep the bromine up, and I guess I'm just suprised how fast it breaks down, I guess I'll have to put it in every day even with the tablets?

I'm just wondering why I get so much algae and most people don't seem to in spas?

Sea Klear has products for spas for algea. They just came out with them this year. Be careful using pool stuff Phos free would have to be scaled down a lot for the gallons.

As far as bromine breaking down, do you start with Bromide to form a reserve and do you shock at least weekly with MPS (non chlorine shock) or chlorine? Shocking re-establishes the bromine in the tub. I feel MPS is best for this. Turn up the feeder that holds the tablets to help keep your bromine level up also.

It is not very common for spa to have algea, most are covered with a hard cover all the time so there is not enough sunlight, plus the sanitation levels kept in spas is higher than pools, so it is harder for it to grow. I am not sure what kind of stretch cover you have, but if sunlight can get through it, algea can grow. Open spas will also have to be shocked more do to dust, pollen ect getting into the water

[Kim Andi]

We just figured out we had algae in our spa as well.

The main reason is the extremely hot weather that we've been experiencing (high 80s and in the 90s) and it's the hottest summer that I've lived in since I've ever owned my first hot tub in 2001.

It's kind of funny too, that the first thing you would see in a lake or pond is algae, especially in the summer.

I'm going to shock ours since we just got it filled about 2 weeks ago for the first time and hopefully that will do the trick.