Algae Splotches on Flagstone Sundeck?

[FlyersDude21]

First summer with a plaster pool in Houston and water temp around 84. We get full sun all day and temps 97-99

We have our pool cleaned weekly and it's been great except today I noticed what I'm guessing is some algae on the sun deck in some of the grout and flagstone. There splotches of it throughout sundeck.

Is this normally something that happens in the summer and then just needs to be brushed off or would it be because of chemical imbalance/ missed area?

What can I do immediately or should I call to get fixed. Don't want anything spreading.

Drain pool so sundeck is exposed and scrub with something?

 

[PoolStored]

Black algae...likely do to poor circulation and chronic under chloritization. After you fix this (see link below), scrub daily and maintain proper FC for your CYA. Link-->FC/CYA Levels

Black Algae

This guide provides a step by step procedure for eliminating black algae in your concrete or gunite pool. Read full post here.

www.troublefreepool.com

 

[FlyersDude21]

Black algae...likely do to poor circulation and chronic under chloritization. After you fix this (see link below), scrub daily and maintain proper FC for your CYA. Link-->FC/CYA Levels

Black Algae

This guide provides a step by step procedure for eliminating black algae in your concrete or gunite pool. Read full post here.

www.troublefreepool.com

Typically I am hands off and let the pool company handle. How long do I scrub daily? It's a decent sized pool maybe 15-20k ga.

I have a nylon brush and don't want to use a metal one on the tanning desk as it's flagstone and will scratch.

So basically cally pool company and tell them to scrub it and triple shock it a few days in a row.

How do I check for better water flow? Pool rungs 8+ hours overnight

 

[PoolStored]

You need to read the black algae guide I posted! The pool company is likely unable to handle this situation. You can try, but, experience here says they will be uninterested. It will be a slog.

So basically cally pool company and tell them to scrub it and triple shock it a few days in a row.

No, read the guide. This is a detailed operation to clear the pool of Black Algae. It is a longer term process, and requires attention.

@Katodude is our resident BA expert. We'll see what he says, but you need to get in there and break the biofilm of all the BA spots. Bamboo skewers work great. Again, read the guide...Link-->Black Algae

 

[FlyersDude21]

I would need the pool company to still maintain the pool and dump chemicals in since they do all service. I'll have them triple shock and clean filter but I am wondering if they didn't maintain the levels to begin with but it's been blue and clean so who knows. I really don't want to but amd store chemicals.

Since it looks contained to the sun deck can I lower water to just below and scrub with something which might have better effect?
@Katodude

Because it's on the flagstone deck I would think a metal brush would scrape the flagstone bad. Can I use a nylon one?

Also seen people say run chlorine tabs on the algeo and also buy
Applied Biochemists 406303A Black Algaetrine Amazon.com

 

[Katodude]

I am struggling to understand is this on the deck around the pool, or in the pool?

If it is in the pool triple shocking most likely will not do anything. And to answer the second part of your question, yes they did not maintain the levels to begin with. That is how you get algae, black, or any other color.

Usually a nylon brush will not disrupt black algae but you can keep trying. If it is fairly localized you can use a wooden bbq skewer to pick at it. You can also try a weak pressure washer, but be very careful with flagstone.

Then get a 1 gallon pump sprayer fill it will LC and spray those spots that you just cleaned.

Tell your pool company they need to maintain FC higher or those spots will just come right back.

 

[FlyersDude21]

On the sundeck in 4 to 5 in of water. It's not as noticeable on the darker sun deck but that's why I don't want it to spread everywhere.

Sorry If I'm rattling off a zillion questions all at once but I have so many.

Would it make sense to drain the pool below the sun deck to work on it? Maybe I could use harsher chemicals and would be easier to rub a tablet on it. You has mentioned spraying with LC so do I do that under the water somehow or drain and spray directly on those scrubber spots?

I see things like use a wire brush but that would scratch up all the flagstone.

1. Will it spread to other parts of the pool?

2. How are black algrea chemicals like the one I listed which say they are specific for that but raise the metal level. Saw this one as well
In The Swim Black Algaecide – Copper Sulfate Pentahydrate - 1 Quart Amazon.com

3. Could I rub tri chlorine tabs on it?

4. After I scrape and power wash or whatever , can we triple shock?

5. The pool is about 8 or 9 years old and we are a second owner so I'm wondering if maybe this could have always been there but just came back because the levels were thrown out of whack?

6. Should I fire my current pool company and get another? As mentioned, everything's looked great up until this.

 

[Katodude]

1. If you FC is low yes it will spread to other parts of the pool.
2. Never add metals to your pool. Period.
3. You can but that is not my favorite method. First you need to break the surface of the BA.
4. You can but we dont use terms like triple shock around here. It’s a weasle word. Does not mean anything. We talk in terms of FC and CYA levels. You will need to maintain you FC at 20% of your CYA.
5. Once you have BA you pretty much have it for life. After you get rid of it, it’s a matter of keeping your FC level high enough so it does not come back.
6. You should fire your company, buy a good test kit and take over control of your pool. That is what we advise here. However, if that is not something you want to do thats ok. But at least get a good test kit (TF-100 Pro) and supplement what they do.


I dont like the wire brush idea either. No need to drain if you are only working in 5” of water. Test a pressure washer to make sure you are not going to damage anything. The 5” of water in the pool will help act as a buffer. Otherwise use a wooden BBQ skewer to pick at the spots. Yes spray the LC on those spots. You can even just take a few jugs of the strongest stuff you can find and dump it directly there. It will wash over the whole area then dissipate into your pool.

 

[FlyersDude21]

Here are today's levels. They came out Friday afternoon for last service. We looked today and about 2-3 pucks still in there.

Outdoor temps around 98 and pool 85

 

[PoolStored]

To manage your pool and get rid of the BA, you absolutely need your own test kit. Link-->Test Kits Compared

 

[cwswifty]

Here are today's levels. They came out Friday afternoon for last service.



View attachment 591654

Looks like you are paying good money for typical "dump and run" pool "services". You really need to fire them and take control of your pool. You spent money to now have black algae and no chlorine. Things are about to get much worse if you don't make the appropriate changes.

 

[FlyersDude21]

Looks like you are paying good money for typical "dump and run" pool "services". You really need to fire them and take control of your pool. You spent money to now have black algae and no chlorine. Things are about to get much worse if you don't make the appropriate changes.

I'm going to start doing this asap. Which test kit?

Pro or non pro and but a stirrer on the side?

 

[PoolStored]

Pro.

 

[cwswifty]

I'm going to start doing this asap. Which test kit?

Pro or non pro and but a stirrer on the side?

You will not regret taking charge of your pool. Once you clean up what the pool service people have caused it will be much easier than you may expect.

Yeah get the Pro with the stirrer. If you have a salt water pool get the TF-Pro Salt.

When you get a chance fill out your signature with your pool's details so that the experts here can better guide you.

Create Your Signature - Further Reading

www.troublefreepool.com

 

[FlyersDude21]

You will not regret taking charge of your pool. Once you clean up what the pool service people have caused it will be much easier than you may expect.

Yeah get the Pro with the stirrer. If you have a salt water pool get the TF-Pro Salt.

When you get a chance fill out your signature with your pool's details so that the experts here can better guide you.

Create Your Signature - Further Reading

www.troublefreepool.com

Thanks. Just ordered.

Really hoping I can get this stuff cleared up quickly and back on track over the next week.

Is there anything that you would recommend doing now as in today or tomorrow other than scrubbing the BA?

I'm assuming I need chlorine as soon as possible or shock.

 

[Katodude]

You want liquid chlorine.

Scrub the black algae then dump liquid chlorine on it.

If we are to believe the results of your pool company you will need a lot of liquid chlorine as your CYA (Stabilizer) is very high.

 

[FlyersDude21]

You want liquid chlorine.

Scrub the black algae then dump liquid chlorine on it.

If we are to believe the results of your pool company you will need a lot of liquid chlorine as your CYA (Stabilizer) is very high.

Thanks. My pool company is coming in today to put shock/ liquid chlorine immediately. I'm going to start scrubbing and also crumble up tablets on the BA.

Do you recommend calcium hypochlorite or any type of LC work?

Can you also clarify earlier when you said put LC in a sprayer and hit the spots? Do I just put the spray nozzle under water and spray where I scrubbed. I just didn't know how this works because in my head the water will just push it away or dilute it versus for instance, soaking a dry weed with glyphosate.

 

[Katodude]

I do not recommend putting tablets on the BA. They are highly acidic and could damage your flagstone.

Sodium Hypochlorite, NOT Calcium Hypochlorite which is a powder.

Go directly to Walmart (or HomeDepot, or Lowes, or wherever you can get strong LC). Buy at least 5 gallons of their Pool Essentials liquid chlorine. After you scrape the BA pour two gallons all over that sun deck. LC is heavier than water and it will wash over the area. Save a gallon for the pump sprayer. Yes, put the nozzle under water and spray where you just scrubbed. For a very short time the BA will get a very big dose of chlorine that will help kill the roots that you have exposed.

Now it’s not a one and done. You will have to keep your FC high for the next several weeks. Your new test kit will help you get the levels right.

 

[FlyersDude21]

Grabbed the pool essentials, poured and then scraped with nylon brush on one part. Came right off easily.

Now back to me tests above. I opened the chlorinator and there was 3 pucks in there still so why would it be reading FC - 0. Is that small amount of algae eating it that fast? Is the chlorinator broke ? How do I check it's running properly.

Also based on my numbers, anything else need to be added? I have a new company coming tomorrow to help get things balanced out while I wait for the kit and learn

 

[Katodude]

We dont trust test results from anyone but the owner. Nobody cares about your pool more than you do.

Physically disrupt those spots then pour LC on them. The sooner the better. Thats pretty much it for now. After using the first two gallons of the LC, I would limit your adding to 1 gallon per day until you get your test kit.

Once you get your test kit, and you post a full set of results there is going to be a lot more information that we can provide.

There are some articles you should read posted. I am 98.75463% sure you will be advised to SLAM your pool, so read up on that. That will be based upon doing an OCLT, so read up on that.

This is all pretty easy, and the experts here have your back.