hello. This is great site. I had a pool in el paso,tx built in 2007 and have always had trouble with black algae. We have acid washed it twice since new and the black aglae comes back after about a year. I had a local pool guy that was highly recommended come take a look and suggested that i replaster the entire pool because black algae is very difficult to remove and keep away once it has been in the pool. Is this my only option or can acid wash it again and maybe sand the walls or wash it with bleach? I would really hate to replaster it already but if that is the only option, I may have to. thanks.
Black Algae Problem
- Thread starter omsrex
- Start date
Welcome to TFP.
While I will agree that black algae can be a problem to completely get rid of, once you do, if you'll maintain the levels recommended here it will not come back.
The problem with black algae is that most people never fully get rid of it and the first time the FC dips a little low for the CYA you have it pops back up.
While I will agree that black algae can be a problem to completely get rid of, once you do, if you'll maintain the levels recommended here it will not come back.
The problem with black algae is that most people never fully get rid of it and the first time the FC dips a little low for the CYA you have it pops back up.
thanks for quick reply. I only have balck algae problems on the walls and floor of the pool. the water is always sparkling clear. it is a salt water pool. what would be the easiest way to permantly remove it either acid wash or slam, or some other method? It seems like slam takes a lot of work and i really do not have the time to devote to it. acid washing i can get someone to do it. what do you think?
so replastering probably is not necessary?
so replastering probably is not necessary?
The biggest thing about black algae is that you have to scrub the head off each spot of it and expose it to the chlorine in order to kill it.
Draining and bleaching the pool may work, but unless you keep on top of the chem levels, it will probably come back.
Unless the surface is in terrible shape it probably doesn't require replastering.
Painting or coating is just a short term stopgap measure. In a couple of years you'll be back worse than you are now because then you'll have to remove what's left of the coating and the old plaster.
Draining and bleaching the pool may work, but unless you keep on top of the chem levels, it will probably come back.
Unless the surface is in terrible shape it probably doesn't require replastering.
Painting or coating is just a short term stopgap measure. In a couple of years you'll be back worse than you are now because then you'll have to remove what's left of the coating and the old plaster.
thanks for the reply. I was thinking of draining, acid washing, maybe sanding or using a wire brush, acid washing with bleach instead acid ( i don't know what you that), then power washing. The surface of the plaster is in good shape, no cracks. It is a little rough, that is the reason i was thinking of sanding or wire brushing it. please let me know what you think. also what is the best way to smooth the plaster?
thanks again
thanks again
You can have the plaster sanded if it's not in too bad a shape, but normally if it's very rough it's time for a replaster anyway.
is plaster sanding something i can do myself or do i need to hire a contractor. if i can do it myself, what is best to use? thanks
Search Youtube for pool plaster sanding and take a look at what's involved. while you may be able to do it yourself, I'm not sure that you want to.
My reply is blunt but I do not intend it to be rude.
Black algae occurs in pools that have been low in chlorine for a VERY long time. Once established, it takes a regimen of high chlorine for a long time to be sure it doesn't return.
You can do all the draining, smoothing, acid washing that you like but until you get an understanding that it is lack of chlorine that is causing your problem, the algae will simply return.
How will you find time to do all the mechanical things (acid wash, smoothing plaster, draining, power washing) if you do not have time to balance your chemistry?
Black algae occurs in pools that have been low in chlorine for a VERY long time. Once established, it takes a regimen of high chlorine for a long time to be sure it doesn't return.
You can do all the draining, smoothing, acid washing that you like but until you get an understanding that it is lack of chlorine that is causing your problem, the algae will simply return.
Welcome to the forum 
Can you post some pics to show how bad the BA is?
Do you use a stainless steel algae brush? It is the only brush to knock off the heads of the BA to allow the chlorine in to kill it. It is a real labor job - brushing, daily.
It will help us help you if you add your location to your profile and your pool & equipment specs to your sig. Use the User Control Panel, upper left menu bar, under TFP logo
Can you post some pics to show how bad the BA is?
Do you use a stainless steel algae brush? It is the only brush to knock off the heads of the BA to allow the chlorine in to kill it. It is a real labor job - brushing, daily.
^^^^^^Repeating this for emphasis. ^^^^^^
It will help us help you if you add your location to your profile and your pool & equipment specs to your sig. Use the User Control Panel, upper left menu bar, under TFP logo
I'm going to suggest if you don't have one to get yourself a good test kit to help you maintain the proper water chemistry. It's the only way to keep your water chemistry at the proper levels.
Here are the kits that we recommend.
pool-school/pool_test_kit_comparison
I'm also going to suggest spending sometime reading in pool school. Here are some articles to take a look at.
pool-school/pool_water_chemistry
pool-school/chlorine_cya_chart_shock
pool-school/water_balance_saltwater_generator
If you could add all your pool and equipment info to your sig it will help us help you better.
Hope you enjoy the forum and welcome to TFP !!
Here are the kits that we recommend.
pool-school/pool_test_kit_comparison
I'm also going to suggest spending sometime reading in pool school. Here are some articles to take a look at.
pool-school/pool_water_chemistry
pool-school/chlorine_cya_chart_shock
pool-school/water_balance_saltwater_generator
If you could add all your pool and equipment info to your sig it will help us help you better.
Hope you enjoy the forum and welcome to TFP !!
It is easy to get lazy with maintenance when you have an SWG. What I found is that black algae will form in any rough surfaces and along the water line when the FC is measurable but low. It's a bear to get rid of.
Could you post a picture that might show how rough your plaster is? Drained, this is what my pool surface looked like. I had to keep FC levels at about 6 ppm even with the SWG or I had black algae problems at the shallow end where the pool surface was rough.
Could you post a picture that might show how rough your plaster is? Drained, this is what my pool surface looked like. I had to keep FC levels at about 6 ppm even with the SWG or I had black algae problems at the shallow end where the pool surface was rough.
I am planning on emptying it in about a week or 2. I will take some pics before I empty it and drained and after it is cleaned up. I also have granite tile instead of the regular porcelain tile which is a bear to clean with the calcium deposits. I was even considering changing the tile for glazed porcelain tile.
I assume it is high CH. The water in El Paso is very hard or maybe the salt? But yes I would like to discuss it.
It could be high CH, it could be salt, but it also could be issues with pH and possibly TA. Do you have a way to get an accurate set of chemistry test numbers?
Yes, I have one of the taylor kits. Should I check it before emptying it too? Or just after cleaning and refilling?
Don't worry about it for now, do your drain and refill and we will get you on the right path when the time is right.
SWG systems are notorious for driving up pH. You need to have your TA around 70 and keep an eye on the pH at least once per week. Also, adding borates (when you have TA in check) may help to stabilize your pH, if needed.
SWG systems are notorious for driving up pH. You need to have your TA around 70 and keep an eye on the pH at least once per week. Also, adding borates (when you have TA in check) may help to stabilize your pH, if needed.