Black dust coming out of sand filter/salt pool, 25,000 gallon inground, vinyl liner

Nrwcastle

New member
Jul 19, 2020
3
Louisville, KY
Took 3 weeks to get crystal clear H20 after pool was opened 7/3; drained almost half of H20. Pool sand was replaced August 2019; ph, alkalinity, FC all ok, stabilizer slightly high, hardness slightly low, no TC measuring. Water crystal clear. No sediment on floor when pump/filter are off but when circulating, constant build-up of black "dust" collects on pool floor. Vacuuming to waste several times daily and adding fresh H20. Yesterday added gel clarifier to pump basket to "coat" inside of filter. Backwashed/rinsed. Continual problem for 3 weeks; nothing works. Put 3 phosphate tabs in skimmer 3 weeks ago. What can I do? I am at my wit's end. This pool was my hubby's baby and he passed away; I'm 75 and finding it very difficult. Can anyone help?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,019
Laughlin, NV
Welcome to the forum!
Can you post your test results that you got from your own test kit?
No need to use all the odd pool store potions. When you say 'black' dust, does it poof away when you brush/vac? Is it really black or dark brown in color?
I suggest you read ABC's of Pool Water Chemistry.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Very. very sorry for your loss. 👼 Not the way we like to see new members arrive, but we're very happy to have you find us. We can help you, take care of the pool equipment and water. Easier and for less money. You will have to break a few old habits and do just a bit of reading, but we'll help. So first the bad news ...
Yesterday added gel clarifier to pump basket to "coat" inside of filter.
Unfortunately, that may have ruined the filter media. Since you backwashed, you must have either a sand or DE filter. Please update your signature with all of your pool info and equipment (test kit as well). See mine as an example,. If you need help, let us know. Also, the phosphate tabs do nothing to help and we almost never add anything directly to the skimmer.

Now for the better news:
- Eventually we'll help you get to the bottom of the black stuff, but for now, you need to ensure the water is clear and sanitary. To do that, test results are #1. Either from a TF-100 or Taylor K-2006C. I recommend the TF-100. See Test Kits Compared
- Stay out of the pool store. They will give you bad advice from marginal water testing and sell you unneeded, over-priced chemical products. Everything you need is in my signature. The money you save from staying out of the pool store alone will pay for a TF-100 test kit many times over and you'll have less work to do with the pool.

If this sounds too good to be true, it's not. Unfortunately the pool store industry makes a ton of money by giving customers generic (or bad) advice, then we go back, and back, and back again. Here at TFP we make no money by helping you. Everyone here volunteers because we've been through it and know how easy proper pool care can be.

Refer to those links in my signature, make sure you have a TF-100 test kit, and let us know how we can help you along the way.

Just to give you an idea how nice your water can look with proper testing and basic household products, see the link below.

 

Nrwcastle

New member
Jul 19, 2020
3
Louisville, KY
Welcome to the forum!
Can you post your test results that you got from your own test kit?
No need to use all the odd pool store potions. When you say 'black' dust, does it poof away when you brush/vac? Is it really black or dark brown in color?
I suggest you read ABC's of Pool Water Chemistry.
Thank you for your help but I've decided that the filter is not working. The pool water is clear and balanced but I keep getting black dust on the bottom. Normally, I run my equipment 24/7, but for the last 3 evenings I vacuumed then shut everything off for the night. In the mornings the pool floor was clean; but after about an hour of the system operating the black dust starts building. Whatever it is is coming out of the filter. Which, by the way, never seems to need backwashing; which again leads me to thinking it's not working. It's a Sand Dollar and is only a year old. Any suggestions for this? Thanks.
 

Nrwcastle

New member
Jul 19, 2020
3
Louisville, KY
Very. very sorry for your loss. 👼 Not the way we like to see new members arrive, but we're very happy to have you find us. We can help you, take care of the pool equipment and water. Easier and for less money. You will have to break a few old habits and do just a bit of reading, but we'll help. So first the bad news ...
Unfortunately, that may have ruined the filter media. Since you backwashed, you must have either a sand or DE filter. Please update your signature with all of your pool info and equipment (test kit as well). See mine as an example,. If you need help, let us know. Also, the phosphate tabs do nothing to help and we almost never add anything directly to the skimmer.

Now for the better news:
- Eventually we'll help you get to the bottom of the black stuff, but for now, you need to ensure the water is clear and sanitary. To do that, test results are #1. Either from a TF-100 or Taylor K-2006C. I recommend the TF-100. See Test Kits Compared
- Stay out of the pool store. They will give you bad advice from marginal water testing and sell you unneeded, over-priced chemical products. Everything you need is in my signature. The money you save from staying out of the pool store alone will pay for a TF-100 test kit many times over and you'll have less work to do with the pool.

If this sounds too good to be true, it's not. Unfortunately the pool store industry makes a ton of money by giving customers generic (or bad) advice, then we go back, and back, and back again. Here at TFP we make no money by helping you. Everyone here volunteers because we've been through it and know how easy proper pool care can be.

Refer to those links in my signature, make sure you have a TF-100 test kit, and let us know how we can help you along the way.

Just to give you an idea how nice your water can look with proper testing and basic household products, see the link below.

Thank you for your suggestions and I will definitely get a different test kit next year. I'm in Kentucky and I normally close the pool the beginning of September. Anyway, I've decided that it's definitely a pump/filter issue. I have a Sand Dollar which has only had 8 months total use and has already had a lateral replaced ($423). My water is balanced and sparkling clear but I get black dust on the bottom continually. Normally, I run my equipment 27/7 but three evenings ago, I vacuumed and shut everything down. In the morning, the pool floor was clear. I've done that now for 3 nights, clear floor every morning when the pump/filter isn't running. But after about an hour of running, the build-up can be seen. So this junk is coming out of the filter. It's not a water issue. Plus, I never have to backwash. The pressure needle on the dial never seems to move. Because of the virus I wasn't going to open the pool this year but I decided to open it late - 7/3. It took three weeks for the water to clear after being closed for the winter (normally it takes about 3/4 days). But really the water only cleared because I drained half of it and constantly was vacuuming to waste and adding more water daily. I have wasted 1000's of gallons of water and 100's of $$'s. I have contacted Pentaire but the customer service guy is out till Monday. Do you have any suggestions? I appreciate your help.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
34,357
Sebring, Florida
Welcome to the forum :wave:

The only suggestion I would offer is that you have made up your mind that you do NOT have a chemistry issue and I would disagree. 95/100 instances of new posters with your symptoms have chemistry issues......and the big majority of them don't think so either.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
I have wasted 1000's of gallons of water and 100's of $$'s.
Next year we hope you'll let us help you with that. Since you are planning on waiting until next season to get one of those recommend test kits, anything right now would be guessing on our part. We don't want to be like the pool store sending you down the wrong path. :brickwall: Even when water is clear, you would be surprised what we learn from proper test kit results. In the meantime, I would recommend you save and read all those links provided above an in my signature. Also make sure to update your signature as well with all y our pool and equipment info. Lots of folks happy to help. Have a nice weekend. :swim: