Residue Settles On Bottom Of Pool

[billydee]

Hi, new guy here.

We bought an Intel pool and have had it set up for about a month now. We use a solar blanket and it catches debris from falling into the pool and it is quite clean.

However, there is a yellowish residue that settles on the bottom and we have tried to vacuum it but it seems to be passing through the dirt container on the vacuum and makes it way back into the pool and I am guessing it is very fine. My g/f feels that it is a chemical and said she noticed it after putting the chemicals in.

She checks the readings every other day and is satisfied with them.

Any suggestions?

Thanks in advance.

[quantumchromodynamics]

It is most likely mustard algae or pollen. What chemicals did your girlfriend put in the pool? What are all of the chemical readings? If it is mustard algae, you need to shock the pool and keep it at shock level until all of the algae is gone. Use bleach or liquid chlorine to shock the pool.

(This assumes that you use chlorine, and not Baquacil. If you use Baquacil, do not use chlorine.)

[quantumchromodynamics]

After clearing the mustard algae, you need to maintain your chlorine level very carefully or the mustard algae will come back.

You could also use a maintenance dose of Polyquat 60 aka: poly [oxyethylene (dimethyliminio) ethylene (dimethyliminio) ethylene dichloride] 60% as an additional measure to prevent reoccurrences.

[billydee]

Hi Quantum and thanks for the help.

She put in ph Up as it was on the low side, ph Plus, hth Regular chlorinator to shock it and also Stabalizer and conditionor. She also tried liquid clarifier.

The chlorine level reading says that the level is fine. How much bleach do you think we should add and I assume you are talking regular household bleach and not the granules?

Thanks.

[quantumchromodynamics]

Free Chlorine = ?

Combined Chlorine = ?

pH = ?

Total Alkalinity = ?

Calcium Hardness = ?

Cyanuric Acid = ?

Yes, regular household bleach. It should be labeled as 6.00% Sodium Hypochlorite. Only use regular Clorox, and not anything with a scent. When you say "Intel" pool, I am assuming that you mean "Intex", right? What do you have for a pump and filter? It would also help if you could vacuum to waste, and not through your filter.

[spookyproud]

We had the same problem with our new pool both last August and the spring of this year. After struggling and no help from the first two pool stores I finally found one who told me it had to be mustard Algae.

It looked like sand in the bottom of the pool.....but when you tried to vacuum it would spread in the water like a cloud of smoke. Later (as I was not controlling it) I started getting a yellow/green stuff on our stairs.

She had me treat it with a mustard algae killer and then high amounts of chlorine. I ran the pump for 24 hours straight too. Then after the first shock---I did a second shock 48 hours later. Ran the pump for another 24 hours.

You need to run your pump for one hour for every 10 degrees of heat. So if its 90 degrees outside....you need to run it for 9 hours.

We were not told that---we were told to only run it 8 hours on low or 3 hours on high....from the place who sold and installed it.

Also, Shock in the evening. Try to find a place that will sell liquid chlorine. It is better and cheaper. (we were using the granule shock) that they said we could swim after you threw it in. That is not true either!

Then use your algaecide in the the mornings.

Our pool is crystal clear and we are loving it!!!

We are no longer walking out with $100.00 worth of chemicals every week either.

[chem geek]

We had the same problem with our new pool both last August and the spring of this year. After struggling and no help from the first two pool stores I finally found one who told me it had to be mustard Algae.

It looked like sand in the bottom of the pool.....but when you tried to vacuum it would spread in the water like a cloud of smoke. Later (as I was not controlling it) I started getting a yellow/green stuff on our stairs.

She had me treat it with a mustard algae killer and then high amounts of chlorine. I ran the pump for 24 hours straight too. Then after the first shock---I did a second shock 48 hours later. Ran the pump for another 24 hours.

You need to run your pump for one hour for every 10 degrees of heat. So if its 90 degrees outside....you need to run it for 9 hours.

We were not told that---we were told to only run it 8 hours on low or 3 hours on high....from the place who sold and installed it.

Also, Shock in the evening. Try to find a place that will sell liquid chlorine. It is better and cheaper. (we were using the granule shock) that they said we could swim after you threw it in. That is not true either!

Then use your algaecide in the the mornings.

Our pool is crystal clear and we are loving it!!!

We are no longer walking out with $100.00 worth of chemicals every week either.

I'm glad you finally got some advice that cleared your pool of yellow/mustard algae; some pool stores actually know what they are doing. I'm also glad you found some of the information on this site helpful. Do you recall your pool's Cyanuric Acid (CYA) and typical Free Chlorine (FC) level when you first noticed the algae (a previous post said 30 ppm, but was that a pool store measurement? were you ever using stabilized chlorine, either Trichlor pucks/tabs or Dichlor powder/granular)? Do you know the name/brand of the mustard algae killer (algaecide) that you used? Technically, an algaecide is not required and instead a shock level of chlorine with an FC that is 60% of the CYA will get rid of the yellow/mustard algae, but this becomes impractical if the CYA is high.

So most yellow/mustard algaecides are one of two things: either sodium bromide or an ammonium based compound. The former turns the pool into a bromine pool while the latter creates monochloramine. Both will kill algae just as chlorine would, but bromine and monochloramine will not combine with CYA so they will be at full-strength. So when the CYA level is high, these products are a "workaround" for the CYA making chlorine far less effective. They do not solve the fundamental problem of the high CYA that can only be lowered through water dilution. If the pool store didn't even mention CYA to you or test for it, then they only half-solved your pool's problems.

As you point out, yellow/mustard algae is like dust or powder, it tends to grow on the shady side of the pool, and it is about twice as resistant to chlorine as regular green algae. It is also insidious as it will come back if there is even a small amount that you don't kill completely so you need to check behind light niches, removable stairs, poles and other equipment that should soak in the shocked pool, etc. Even swimsuits should be washed. You don't want to reintroduce the algae back into the pool.

It is not true that you cannot swim for 24 hours after adding chlorinating liquid or bleach. All sources of chlorine that dissolve into the pool mix fairly quickly and thoroughly. I've done both dye tests and chlorine measurements tests in my pool and it's perfectly safe to swim even after 10 minutes, but you can wait 20-30 minutes to be extra safe. This assumes that you pour the chlorine slowly over a return flow in the deep end with the pump on. In a vinyl pool, one can also lightly brush the side and bottom of the pool to ensure thorough mixing. If the circulation is poor, you can wait longer, but in pool's with decent circulation the chlorine mixes everywhere rather quickly -- you can measure this for yourself using a FAS-DPD chlorine test kit and see how long it takes for the chlorine level to rise to the expected amount throughout the pool.

Richard

[spookyproud]

We had the same problem with our new pool both last August and the spring of this year. After struggling and no help from the first two pool stores I finally found one who told me it had to be mustard Algae.

It looked like sand in the bottom of the pool.....but when you tried to vacuum it would spread in the water like a cloud of smoke. Later (as I was not controlling it) I started getting a yellow/green stuff on our stairs.

She had me treat it with a mustard algae killer and then high amounts of chlorine. I ran the pump for 24 hours straight too. Then after the first shock---I did a second shock 48 hours later. Ran the pump for another 24 hours.

You need to run your pump for one hour for every 10 degrees of heat. So if its 90 degrees outside....you need to run it for 9 hours.

We were not told that---we were told to only run it 8 hours on low or 3 hours on high....from the place who sold and installed it.

Also, Shock in the evening. Try to find a place that will sell liquid chlorine. It is better and cheaper. (we were using the granule shock) that they said we could swim after you threw it in. That is not true either!

Then use your algaecide in the the mornings.

Our pool is crystal clear and we are loving it!!!

We are no longer walking out with $100.00 worth of chemicals every week either.

I'm glad you finally got some advice that cleared your pool of yellow/mustard algae; some pool stores actually know what they are doing. I'm also glad you found some of the information on this site helpful. Do you recall your pool's Cyanuric Acid (CYA) and typical Free Chlorine (FC) level when you first noticed the algae (a previous post said 30 ppm, but was that a pool store measurement? were you ever using stabilized chlorine, either Trichlor pucks/tabs or Dichlor powder/granular)? Do you know the name/brand of the mustard algae killer (algaecide) that you used? Technically, an algaecide is not required and instead a shock level of chlorine with an FC that is 60% of the CYA will get rid of the yellow/mustard algae, but this becomes impractical if the CYA is high.

So most yellow/mustard algaecides are one of two things: either sodium bromide or an ammonium based compound. The former turns the pool into a bromine pool while the latter creates monochloramine. Both will kill algae just as chlorine would, but bromine and monochloramine will not combine with CYA so they will be at full-strength. So when the CYA level is high, these products are a "workaround" for the CYA making chlorine far less effective. They do not solve the fundamental problem of the high CYA that can only be lowered through water dilution. If the pool store didn't even mention CYA to you or test for it, then they only half-solved your pool's problems.

As you point out, yellow/mustard algae is like dust or powder, it tends to grow on the shady side of the pool, and it is about twice as resistant to chlorine as regular green algae. It is also insidious as it will come back if there is even a small amount that you don't kill completely so you need to check behind light niches, removable stairs, poles and other equipment that should soak in the shocked pool, etc. Even swimsuits should be washed. You don't want to reintroduce the algae back into the pool.

It is not true that you cannot swim for 24 hours after adding chlorinating liquid or bleach. All sources of chlorine that dissolve into the pool mix fairly quickly and thoroughly. I've done both dye tests and chlorine measurements tests in my pool and it's perfectly safe to swim even after 10 minutes, but you can wait 20-30 minutes to be extra safe. This assumes that you pour the chlorine slowly over a return flow in the deep end with the pump on. In a vinyl pool, one can also lightly brush the side and bottom of the pool to ensure thorough mixing. If the circulation is poor, you can wait longer, but in pool's with decent circulation the chlorine mixes everywhere rather quickly -- you can measure this for yourself using a FAS-DPD chlorine test kit and see how long it takes for the chlorine level to rise to the expected amount throughout the pool.

Richard

The first pool place I went to THIS summer also gave me algaecide with copper in it. Which wasnt such a bright idea and had to add metal control into the pool to rid it of the copper.

I just know the product that the second store gave me (and I am very happy with) has really straightened out my pool. We are able to swim daily and no problems with keeping it balanced. We have them check the water at least weekly while I check it daily at home with my own water testing kit. The new pool store gave me "stop yellow" for the algae but as far as what is in it--I do not know.

Our CYA level was 30 when the mustard algae really took off. That was one thing the new pool recommended was adding more.

As far as the chlorine goes.....since we have a child with cancer I am going to go with the recommendations about the PPM on the chlorine levels. I do allow the adults in the home to swim at their leisure if they want to.

Oh...and I took a class on keeping my pool clean.....I am in no way a professional...but at least I can care for my own pool and now understand most of the chemicals etc......I do recommend finding a pool store that host a class.

The overdose of Alkalinity I had from the first pool store is almost---almost taken care of. I have added lots of water and muriatic acid (starting on my third gallon in a month) but I am only 10 ppm high currently.

Yes, I had to keep scrubbing our ladder as the algae kept coming back in that first week of treatment. Currently we do not see any at all.

I also noticed with this algae that I could see little white floating particles in the water. You couldnt see them above the water but with a face mask on---you could see it. I dont have this problem now that I have treated it for the mustard algae.

If you rely on a pool store remember this "not all pool stores are qualified to help you"......they only want your money selling you pool products you dont need. Find one that is reputable. AND---come here and ask these guys if what the pool store salesman are telling you to do.....is the right thing to do.....

[chem geek]

The metal sequestrant just holds the copper in solution, but it does NOT get rid of it. In fact, over time the chlorine will break down the sequestrant releasing the copper back into the water so you will need to keep adding maintenance doses of the sequestrant every so often. The ONLY way to actually remove the copper is through water dilution (drain/refill or backwashing, splash-out, rain overflow).

"Stop Yellow" is sodium bromide so works the way I described. If the CYA level is very high, then it's a way around that, but it wasn't necessary and won't solve a high CYA problem. If you had diluted the water to lower the CYA level (if needed) and then shock with a high FC that was 60% of the CYA level, you would have also killed the yellow/mustard algae. Adding the "Stop Yellow" turns your pool into a bromine pool until over time the bromine outgasses from the pool (over weeks). Your chlorine demand may be higher for a time because bromine is not protected from breakdown from sunlight very much because it doesn't bind to CYA.

That is odd that your CYA was only 30 ppm when your pool got algae. Perhaps the FC level got below 2 ppm for a time though yellow/mustard algae is more chlorine resistant and may not be kept away at a CYA of 30 ppm unless the FC is a minimum of 4.5 ppm. Unless you measured the CYA level yourself with your own good test kit, I'm not sure I would trust the pool store number (they often get the CYA test wrong).

If you want to minimize your chlorine level, then use an alagaecide such as PolyQuat 60 weekly (at extra cost). It sounds like you are doing that in order to minimize FC yet keep algae from growing.