How To Get Rid Of BLACK ALGAE In Your POOL | Swim University

It’s bad enough to discover green algae in your pool. But black algae? Get ready, because you have some serious pool cleaning to do. And no one should swim in your pool until it’s gone. The good news: it’s totally possible to kill black algae. Here is a step-by-step guide on how to get rid of black algae in your pool for good.
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⏰ Timestamps:
00:00 - Introduction to How To Get Rid Of Black Algae
00:24 - What Is Black Algae And Why Is It In Your Pool
00:53 - Is Black Algae Harmful?
01:11 - What Does Black Algae Look Like?
02:14 - How To Kill Black Algae
02:54 - Step 1. Clean Your Filter
03:19 - Step 2. Test And Balance Water
03:52 - Step 3. Brush Your Pool
04:21 - Step 4. Scrub Black Algae Spots
05:08 - Step 5. Brush Your Pool Again
05:19 - Pool Care Course
06:03 - Step 6. Quadruple Shock Your Pool
06:49 - Step 7. Run Your Pump
07:00 - Step 8. Brush Your Pool AGAIN
07:19 - Step 9. Clean Your Filter Again
07:43 - Step 10. Shock The Pool Again
07:56 - Step 11. Run Your Pump Again
08:07 - Step 12. Brush Your Pool AGAIN!
08:19 - Step 13. Test And Balance Water
08:31 - Step 14. Keep An Eye Out For Leftover Black Algae
08:55 - How Do You Prevent Black Algae?
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Hope this video helps you get rid of black algae in your pool! And if you want to learn more about pool cleaning and pool maintenance, subscribe and leave a comment to suggest a future pool care video. And visit www.SwimUniversity.com/pool to get the Pool Care Handbook and Video Course (Use The Promo Code VIDEO for 10% Off!)

[@Cfish613]

hi i would love if you do a video about copper ionizers or even copper sulfate (pristine blue) what do you think of these

[@drdrew3]

This is too much work. How many bags of concrete to fill in a 15,000 gallon pool?

[@pegynol]

I'm feeling the same.

[@JosueOrtiz-hl1dm]

It's not even that much work stop being lazy

[@Weibaolien]

😂😂

[@SolRayz]

Just turn it into a coy pond.

[@bruceha1615]

I think it is easier to just drain it and chlorine wash them.

[@elmamo2000]

That "good luck" at the end was very heartfelt.

[@jimschuler8830]

I've been telling the local frogs to wash their swim trunks, but they just croak at me before jumping in.

[@ryangallagher3291]

😂

[@kurtvandelden6724]

One Tool: Pressure Washer. For a Gunite pools, jump in and get close with the wand tip, wash the walls, remove the black spots.. Then shock with chlorine. Works every time.

[@aarondetrick9894]

I this with my commercial pool. It worked great. If you use the chlorine tab to scrub day before it loosens it up and makes it easier

[@gmaddox2400]

This does work pretty good but be carefully not to get to close to the pool surface with the pressure washer wand. I pressure washed a hole in my pool about the size of a quarter in the diamond bright.

[@drdrew3]

Dynamite gives similar results

[@andresmanzano1138]

It doesn’t always work though. Sometimes black algae is rooted deep into the plaster and the only way to remove it is by hydro sanding layers off the surface…

[@OneAdam12Adam]

Pressure washers are overkill. Pressure washers also SPREAD THE MOLD throughout the area.

[@37christ37]

Hi there, great video and thanks. We struggled with black algae but using chlorine tablets like chalk and rubbing the black dots and patches away works absolute wonders. I didn’t find the extra brushing or using an algae brush to be as useful. Also an algae brush can scratch your marbelite and there is no need to crack the chlorine tablet in half just use it whole. Cheers 👍

[@_Planeview_]

Did all the steps minus the brushing?

[@StudioKpros]

What if the place that needs scrubbing is at the bottom of the pool 6 ft deep?

[@37christ37]

@@StudioKpros fair point. Our pool is only 20,000 litres so it is only 2m deep or so so we don’t have that problem. In my experience the algae tends to grow more where the pool is at its warmest. We didn’t get much algae that deep. I just got in the pool with rubber gloves and water shoes on and scrubbed and it worked really well. Good luck. 👍

[@stronghumantraining]

Wow that was good! THANK YOU!!

[@gailhardy5727]

We have an above ground 18x33 vinyl pool, I kept hearing black algae does not form on vinyl above ground pools, your video does show above ground pool in this video...I have tiny black spots forming that I scrub, and most come off with some effort...I guess I need to follow this video process and see if that helps. Thanks for the video.

[@yassinehilmi7295]

Always a great help. Thanks!

[@TheBaltherion]

Thanks! I have a black algae problem at one of my pools.

[@cocoliasvd]

Good afternoon. Is it possible to get black algae on a new pool, first filled 2 weeks ago? Chemicals seem to be where theybare supposed to be, but I saw this morning 2 areas on the step of the pool with 2 chunks of tiny black balls, and some floating in the water. I got one out, and it was slimy, but my husband insists it can't be black algae. What else could it be?

[@rebeccahill5940]

Hello, I have an inground 30'x40' vinyl liner (over cement) salt water pool w black dots in it which im assuming is black algae. I saw 1 response for an above ground vinyl liner however there was no return reply. Is the removal process for black algae the same as a gunite inground pool? If not could u please give me a step by step process of it. I'm no pool guru so PLEASE be specific as I'm the teacher mom home during the summer taking care of the kids so needless to say poolcare is NOT my forte'😁 thanks in advance!!!!

[@slashdotjeo]

Could you use dichlor instead of cal hypo? I have a salt water pool.

[@meekrodriguez6438]

Awesome video

[@siminakaradimas6496]

Thank you so much! It really worked!

[@Teh_Random_Canadian]

Can you give some details? I have been battling mine for 2 weeks and have done everything in this video, ready to give up

[@cook4onechefdenice647]

Brilliant 🤩

[@updatename6637]

Does this method work for salt water pool chlorinator???

[@anamedina7666]

Thanks

[@anmolgupt7917]

Thanks! That's helpful. I had black algae in my pool and I have been working my a$$ off to remove it :-).

[@PappyNet01]

Did you win the battle against the Black Algae?

[@GiniRisinger]

We have an above ground pool. When we opened it for the first time this season and it was thick green and yellow. So we drained it. I scrubbed it 2 different days with a magic eraser and thought I got it all. We had the pool filled Wed. By Thursday morning we had little black spots all over the bottom. And our pH is above 9 and alkalinity is over 280. I've used pH decreaser 3 days in a row and it hasn't gone down at all. Did a chlorine shock. It did nothing. Black algae still there. We are going to be using a Flip Plop mineral floater system this year. And I can't put it in until the numbers are in the normal range. Any suggestions on how to lower the pH and alkalinity but also kill the algae?

[@cain392]

9:53-10:02 I love you man😂🖤

[@macknumber9]

I have these black little dots that are floating on the surface of the pool...they look like they might be some sort of insect eggs though I am not sure

[@sebastienmartinez2002]

Very helpful. Thanks a lot Matt. ✌️

[@ithirstyforknowledge]

In the end, is it safe to swim in this pool of strong chemicals??

[@THEJavelinX]

Pressure washer works well to scrub it as well, in fact, it works the best. Soooo much easier than scrubbing

[@THEJavelinX]

@Stephen if you're pressure washer is adjustable, lower the pressure so that you don't peel the paint

[@37christ37]

Did you have to drain the pool to do this? You can just get in the pool and rub the black algae marks with chlorine tablets. This works wonders and no need to waste any water 👍

[@THEJavelinX]

@James Maidwell no, the pressure washer nozzle works under water, as long as you keep the actual motor portion out of the water lol. And at the time of year that I had to do this, getting in the water was definitely not an option too cold.

[@louisfain]

I heard PoolRx works on black algae. I don't know to what degree but it seems to me that it is the silver bullet for green algae. anyone with black algae should give it a try.

[@assemblyofthesaintsministr3419]

yes it works

[@tomnguyen1015]

Lol I would have to quit my job and be a full time pool cleaner!!!

[@handmadeetcllc9126]

Can you use the chlorine tablets on a vinyl liner?

[@marbman1587]

no

[@irl8796]

Idk why I am watching this all the way through. I have no algae and a vinyl siding pool.

[@Ohlawd1119]

This must be not in FL because in FL the ideal ranges vary due to the harsh humidity in the summer.

[@JK-hd2zb]

The chlorine level in a Florida pool is generally kept around 3 ppm with alkalinity around 100 and PH 7.4

[@tonyb282]

Happened to me, went to the beach and some toys caused the black alge. I have a question? My tds,and cya are out of control and I think it is about time for a full drain. Could I use liquid chlorine on the areas with the alge or since the water will be drained just break a tab and scrub the areas by hand? Thanks for your help.

[@SwimUniversity]

Sorry you're going through that! The issue is it also might be inside your filter... so while treating it by hand might work, but you also need shock (at some point) going through your plumbing.

[@ryangallagher3291]

I did it but, the calcium hypochlorate left weird dusty sediment on the bottom of the pool and the backwash feature isn’t working on the pool pump. How do I get it out

[@FlyMeAirplane]

vacum to waste is the only way.

[@eddiksa3782]

How do you get at the deep end to scrub? Go in with snorkel to scrub? Would the chlorine be dangerous in high concentrations? How about letting a chlorine tab lay on it and move every few hours?

[@roughneck8260]

you can search for a chlorine tab holder that you attach to you extending pole, they have a couple on amazon. hope that helps, good luck!

[@dianelyall3864]

@@roughneck8260 OK thanks a lot.

[@dianelyall3864]

@@mattuso here are holders to put the chlorine tab in on extension poles.

[@nbknrcr]

I've found that broadcasting shock over those areas where you see it and letting it sit will get rid of the spots

[@dianelyall3864]

@@nbknrcr Thanks

[@DisappearingBoy2010]

Shock the pool, scrub it off, clean the filter. There I just saved you 10 minutes.

[@marksmith2443]

What is a good paper catridge cleaner to kill the algae?

[@pgnandt]

Chlorine.

[@simongilmore5618]

I could really use some help, I got black algee. I don't know how, I haven't used the pool lately so I am not sure why I have it. Scrubbing isn't doing it. Any other suggestions?

[@37christ37]

Rub the black algae marks with chlorine tablets…it works really well 👍

[@mwachner]

Is black mold on the walls of the skimmer receptacle the same as black algae? How do you clean this off?

[@TheMossberg024]

Yes and watch the video

[@stevesobel9665]

Can the shocking be done with liquid chlorine rather than cal hypo? Thanks

[@JK-hd2zb]

liquid chlorine or sodium hypochlorite is a very good sanitizer but is not that good at breaking down organics such as black algae. Could you? I suppose, but I isn't nearly as effective and it will require a much higher concentration

[@kraysee4537]

How long should I stay out the pool after applying black algae destroyer?

[@SwimUniversity]

Do you mean shock? You should wait at least 8 hours

[@marcusdurr3059]

can I powerwash then brush then scrub with tablet

[@JK-hd2zb]

It's more about killing it than removing it. It grows roots into the substrate. you brush to remove the bulk of it and shock the hell out of the roots

[@c1h2r3i4s56987]

high pressure power washing can do serious dmg to the pool surface , but a lower pressure washer with a fan nozzle, putting some bleach in the washer, (if your washer can be filled with bleach ) im sure would help. just don't drain the pool to do so you still need to, my formula is Abrasion and Chorine, Abrasion and Chorine, Abrasion and Chorine, clean filter often like a mad man Abrasion and Chorine, Abrasion and Chorine, Abrasion and Chorine Repeat over and over

[@joleneweaver7578]

How do I get rid of silt

[@c1h2r3i4s56987]

silt? Use flocculant follow the directions on the bottle exactly which will be something like adjust your chem Lvls to X Y and X, add Floc, Run pump for 4 hours, turn pump off for 24-48 Hrs, Then Vacuum to waste, but move slow to not disturb the stuff at the bottom you wanna vacuum out of the pool. If you dont have a multiport value to pump out water, there are ways around it,

[@Stellastar19]

I just opened my pool and it looks like coffee/tea. I don’t have well water. It’s city water. I’ve never had this problem over the past 5yrs of owning a pool. I added chlorine before closing. I seen that could cause iron. It’s weird, I’ve never had a coffee pool for opening

[@SwimUniversity]

Oh interesting! Have you tested the water?

[@Izabella_playz]

what does it mean cuadruple shock, how many ppm is this??

[@BurritoKingdom]

4 times the amount of shock that is recommended for your pool. The normal amount of shock for a 10,000 Gallon pool is 1 pound of shock. So it would be 4 pounds of shock for a 10,000 gallon pool

[@jaygeetv9599]

Use a pressure washer it works and still scrub

[@spikeybabies]

don't for get total dissolved solids. been in the business for 30 years

[@Agent_Charlie]

Could one just drain the pool?

[@cfdpipemajor]

No, you need the water to transport the chemicals (balancing, shock) to kill the buds. Some are able to hard clean the walls (scrub, pressure wash) if the pool is drained but water and product is still necessary.

[@larrygrasse7627]

What about a salt pool ?

[@JK-hd2zb]

Same process but I would recommend bypassing the salt cell during the process

[@77hemi]

@@JK-hd2zb how do you bypass the salt cell? I mean if you used a dummy cell it wouldn't be bypassing it, it would be replacing it

[@ty1291]

Unless I'm missing something why not just buy a black-spot algaecide?

[@gmaddox2400]

Black algae forms a hard shell over it. This is way you can't brush it away. You must first break open the hard shell for any chemical to work. That is why brushing is so important.

[@skycamqp1]

Do I need to shock every week?

[@nandis28me]

Yes, you should be shocking your pool weekly as part of your maintenance routine

[@outlawjodiewales9295]

@@nandis28me how do I do that

[@bharatijoshi3060]

Yes it spoils our cap and goggles

[@williamtaylor8806]

we have had our pool for only a year and we have been the ONLY ones to use it. we use the same suits over and over. could this be caused by the raccoons that love to wash their hands in it? in Belize BTW

[@drdrew3]

Yes. The raccoons can transfer bacteria because they also wash their hands in river water and mud puddles. They also love to poop in the pool which is 10 times more nasty

[@marckirby7356]

Do all this.. or just add 20lbs of cal 90 black algae remover .. Job done

[@JS-cb7rx]

What product is this?

[@anjyel]

I think it would be cheaper to completely drain your pool and pressure wash it 🤣

[@erincarney6534]

I like this idea. I'm ready to concrete my in after the amount of money I've put into it this summer!!!

[@pgnandt]

@@erincarney6534 Drain and chlorine bath. Done it 100 times.

[@Teh_Random_Canadian]

I wish I would have done this! I have been fighting this for 2 weeks... I have spent 200 in clorhine and over 12 hours scubbing and am still not done. Of course my local pool store never told me this, instead they sold me all the chemicals that have done basically nothing

[@alexportugal1212]

You never get rid of it, you just can controle it

[@luishenriquepereiradeolive8597]

lmao xD

[@JK-hd2zb]

Especially since most people don't eliminate the source of the black algae it just comes right back

[@sajidrafique375]

Oh sh... too much work .

[@mardegan86]

Its cheaper to drain water, wash it with muriatic acid and refill it

[@jessicaannes]

You must have very inexpensive utilities. Filling a pool here in Austin costs hundreds!

[@Teh_Random_Canadian]

​@@jessicaannes I am already hundreds into chemicals, not including the amount hours lost and time lost not swimming. I have already spent over two weeks and several hundreds in chemicals. If I knew then what I know now I would have drained it

[@franklee2683]

Algaecide not even reccomended? Really? Ok...im getting my pressure washer out and then will brush/shock pool. The black algaecide is very expensive and does not work in my case! My pool looks great usually,but the black algae sucks.

[@pgnandt]

Still having issues? In 23 years I've battled this 100's of times. You do need colloidal silver in your pool. Trichlor granular for a shock. 4" stainless pole brush for pressure.