White Mold In Spa

by Jackie Perry

I have a 300 gallon spa and use use Baqua Spa products 1,2 & 3 and cartridge filter(have a new one on hand).

There are white floating things in spa and really bad when I remove the filter! The pH, alkalinity and hardness are all in "ok" range on test strips.

Can I shock the hot tub? Can I use Baqua spa oxidizer to shock it? How do I do this?

About a month ago I drain the spa I used Swirl Away(half a bottle) still had white floaties.

Thanks so much!

Thanks for the question Jackie

There's good news and bad new. The good news is that I can help with your situation.

The bad news that Baqua products take time and a skill set to develop. If you're not a stickler, to the smallest detail, of using Baqua products, the water will more than likely get fouled.

It does sound like you have water mold. As the white mold pages says it's similar to having roaches. You see one but there's 10,000 others. The mold is throughout the entire system.

Here's a good but very dry read on Baqua products and their use. It does take some self educating to get right:


There is no one single formula for a hot tub. One might be heavily used while another one may only be used once per week.

You're going to need to do alot of draining and refilling to get rid of the water mold.

First is the drain, refill, then shock with liquid chlorine. It's 5 oz. per 500 gallons to shock the hot tub. Allow this to run through the system, about 1 hour, then drain and refill. I'd suggest doing this process a 2nd time.

Drain and refill after the 2nd shock, then use a product called Sea Klear Spa System Flush. Follow the directions on the bottle. Be sure to clean the filter after each shock. Have 2 filters on hand and rotate them out.

Drain and refill once again.

I'd suggest going to a chlorine based or bleach based form of sanitation. It's much cheaper than Baqua products and will sanitize the hot tub.

You'll need to get some stabilzer (CYA) using Dichlor. This is a stabilized form of chlorine. Once you reach the 30ppm mark, stop with Dichlor and go back to regular liquid chlorine.

For hot tubs you want to focus on water temperature, calcium hardness (CH), total alkalinity (TA) and Potens Hydrogen (pH). We'll say your water temp. is between 100 - 102 degrees.

Keep the CH between 100 - 150ppm, TA at 80 - 100ppm and pH 7.4 - 7.6.

Swimming Pool Chlorine

Pool Shock

Pool Chlorine

Chlorine Tablets

Pool Chlorine Tablets

You can use bleach as this is nothing more than watered down pool chlorine, sodium hypochlorite.

Never allow the chlorine to get to zero as the bacteria will reproduce very quickly, within a matter of hours. You should get a good test kit, Taylor DPD-FAS K-2006 and learn to use it. Don't rely on test strips as they are more convenient but not as accurate.

You need to test the water at minimum every other day and preferably each day. The heat will always cause the chlorine to rapidly decrease, much faster than a pool.

To post a reply, or if you have a similar question, you can see your post on the Q&A page in the "Hot Tub/Spa Questions" category.

Check back to this post for updates or answers.

If you need immediate assistance (within 24 hrs) or for emergency personal assistance, you can make a donation of your choice and I'll answer your questions by phone.

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Hope this helps and have a great Summer.


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Black Streaks In My Hot Tub

by Steve
(Pittston, PA)

After not using my hot tub for a few months, doing nothing but maintaining minimal chlorine, I found several black lines in different places on the hot tub. There were also a few small, black, speckled spots. I drained the tub and attempted to clean off the lines. I got the worst of them off, but could not get them off completely.

I have ordered a new filter and am leaving the tub to dry. Will the dryness and cold temperatures (around 40 degrees) kill the mold? Do I need to refill the tub, run some chemicals through the system, drain it again and refill it again? Are there any particular chemicals I should use?

Hi Steve. We can't jump to conclusions of mold or bacteria. Normally, it could be one of three things, or possibly a combination.

First would be the gel coat wearing down. For that you'll need to get a qualified hot tub guy out there for an inspection.

If that's not it then we can look at the 2 kinds of staining, organic or metal. I would ask if you use well water or if your fill water has metal in it. Some city water does. If so, you'll need to use a metal sequestrant with the HEDP ingredient. Jack's Magic is good.

To get rid of the stain you can rub some crushed up Vitamin C on the affected areas, then rinse well. This is called ascorbic acid.

Next would be organic stain. This can be taken care of using a chlorine tab and a little light rubbing. You can put a tablespoon of bleach on a rag with a bit of water and rub the affected area.

If it is organic then I would suspect you have algae throughout the system. You'll need to refill and super-chlorinate. It's 1.5 cups of bleach per 500 gallons. Doing this a couple of times in a row will normally kill any residual algae in the pipes. You're getting a new filter so there are no worries with that.

For the chemicals, bleach will take care of the mold and bacteria, if that's the problem. For metals, as stated above, Jack's Magic works well.


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Spa Scum Remove

by Natanel

I got a 4 meter spa and since I wasn't using any enzyme, I got a huge scum buildup around the spa. I tried a lot of products that use the "power of citrus". It doesn't help, I need to use something more powerful. Any suggestions?

Hi Natanel. I understand how frustrating that can be. These are a few products that I've used and they seem to work pretty well.

A 50/50 blend of water and white vinegar is great. Very underestimated. You can also use a Magic Eraser. Simple Green is a good alternative but you need to be sure you rinse very well. Scumball and Zorbo from SpaDepot have worked in the past. You can also use Spray-Nine and terry-cloth rags.

Again, any kind of spray or liquid you put in your spa you need to be sure you rinse very well.

Hope this helps.


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