Is this yellow algae?

nnhrm

Member
Apr 18, 2021
12
Ottawa, Canada
Hi guys,

We bought this house last year and the pool has always had this stuff at the bottom. Sometimes it seems like it comes from the filter because we will vacuum it up and then the next day after running the filter overnight it will be back.

182741932_831028980839355_3325657808276719100_n.jpg


183563601_490835135387327_257641884310755487_n.jpg
 

Attachments

  • 183471233_828766834429548_6252606407190978447_n.jpg
    183471233_828766834429548_6252606407190978447_n.jpg
    558.2 KB · Views: 1

amwillg

Gold Supporter
Apr 5, 2021
38
Louisville, KY
Pool Size
34000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Autopilot Digital PPC4 (RC-52)
Gonna go out on a branch and assume that you have a sand filter?
Possibly a damaged lateral with sand escaping
 

proavia

LifeTime Supporter
TFP Guide
Feb 6, 2015
2,505
Chandler AZ
Pool Size
12300
Surface
Plaster
Chlorine
Liquid Chlorine
Tell us a bit about your pool and test kit... actually, put all that info in your signature so we can see it each time you post. That will better help us to help you.

Post a full set of current test results
FC
CC
pH
TA
CH
CYA
Water temp
Salt level (if using SWG)
 

nnhrm

Member
Apr 18, 2021
12
Ottawa, Canada
Sorry about that, I'm new here.
Yes, we have a sand filter. That's interesting because that's the first thing we thought when we saw it. Thought it looked like sand.

Current test results 185219072_217905976471144_794601943201972810_n.jpg181605397_497706631580674_262513821690744599_n.png181768292_2983541475200570_6850196553357729600_n.png

TC 5
FC 5
CC 0?
pH 6.8
TA 40
CH 250
CYA 0-30
Water temp -- not sure, it is 8 degrees celcius outside and hasn't been above 15 for about a week, and we aren't heating it
 

proavia

LifeTime Supporter
TFP Guide
Feb 6, 2015
2,505
Chandler AZ
Pool Size
12300
Surface
Plaster
Chlorine
Liquid Chlorine
We don't give much credence to test strips or pool store results as they have been proven time and time again to be inconsistent. It would be best for you to obtain one of the recommended testkits - Test Kits Compared.
 

nnhrm

Member
Apr 18, 2021
12
Ottawa, Canada
We don't give much credence to test strips or pool store results as they have been proven time and time again to be inconsistent. It would be best for you to obtain one of the recommended testkits - Test Kits Compared.
Ah okay. Yeah, I find them pretty hard to read in terms of the colours as well. Never really sure where I'm at.
Perhaps we will get it tested at the local pool store this week and report back.
Thanks

Edit: oh I miss read that - really? no pool store results. wow. okay. thank you!
 

phonedave

Well-known member
May 30, 2012
985
Montville NJ
Pool Size
17000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Hayward Turbo Cell (T-CELL-5)
1) As others have said, invest in a good test kit - it is going to make a world of difference. Think of it this way, if you are diabetic you want to know your sugar is 134 so you can does accordingly. You don't want to say "this strip looks yellowish red so I think my sugar is between 110 and 140 so I will take some insulin". Same thing goes for your pool. With test strips all you have is a best guess.

2) Once you get a good test kit, if it shows it is not algae then it could be sand from your filter. I have a DE filter that occasionally does the same thing. I use a slime bag and it works wonders.
 

nnhrm

Member
Apr 18, 2021
12
Ottawa, Canada
1) As others have said, invest in a good test kit - it is going to make a world of difference. Think of it this way, if you are diabetic you want to know your sugar is 134 so you can does accordingly. You don't want to say "this strip looks yellowish red so I think my sugar is between 110 and 140 so I will take some insulin". Same thing goes for your pool. With test strips all you have is a best guess.

2) Once you get a good test kit, if it shows it is not algae then it could be sand from your filter. I have a DE filter that occasionally does the same thing. I use a slime bag and it works wonders.
How would the test kit tell me whether or not it is algae? Is it to do with the combined chlorine levels or does it have a specific test for algae?
Thanks
 

Enjoying this content?

Support TFP with a donation.

Give Support

phonedave

Well-known member
May 30, 2012
985
Montville NJ
Pool Size
17000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Hayward Turbo Cell (T-CELL-5)
Ah okay. Yeah, I find them pretty hard to read in terms of the colours as well. Never really sure where I'm at.
Perhaps we will get it tested at the local pool store this week and report back.
Thanks

Edit: oh I miss read that - really? no pool store results. wow. okay. thank you!

There are two issues with pool store results.

Sometimes the person doing the test really does not understand the test, and they just "follow the instructions" - sort of. People have gone into two different pool stores with the same sample of water and received wildly different results.

I am not going to say pool stores outright lie, but they do have an incentive to sell you expensive chemicals, and if tests support that story ...... If you do go to a pool store keep that in mind when they tell you that you NEED clarifier, algae out, polyquat, and whatever other potions they try to sell you.
 

phonedave

Well-known member
May 30, 2012
985
Montville NJ
Pool Size
17000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Hayward Turbo Cell (T-CELL-5)
How would the test kit tell me whether or not it is algae? Is it to do with the combined chlorine levels or does it have a specific test for algae?
Thanks

Good - no combined chloramines (Not combined chlorine) mean probably no 'infection' in your pool.

Total Chlorine (or Combined Chlorine) = Free Chlorine (Chlorine waiting around for something to do) + Combined Chloramines (Product of Chlorine attacking organic matter - it gets off gassed eventually)
no Combined Chloramines likely means no active infection.

Better - Pass a OCLT - Overnight Chlorine Loss Test.

Chlorine gets used up in two ways (basically) From UV rays (the sun) and from attacking organic matter
You measure your CL in the evening after the sun goes down, and then you measure it again in the morning before the sun comes up. If it has not changed (or changed 0,5 ppm or less), then you are good. If it has changed, then something organic is in your pool and consuming it.
 

nnhrm

Member
Apr 18, 2021
12
Ottawa, Canada
Good - no combined chloramines (Not combined chlorine) mean probably no 'infection' in your pool.

Total Chlorine (or Combined Chlorine) = Free Chlorine (Chlorine waiting around for something to do) + Combined Chloramines (Product of Chlorine attacking organic matter - it gets off gassed eventually)
no Combined Chloramines likely means no active infection.

Better - Pass a OCLT - Overnight Chlorine Loss Test.

Chlorine gets used up in two ways (basically) From UV rays (the sun) and from attacking organic matter
You measure your CL in the evening after the sun goes down, and then you measure it again in the morning before the sun comes up. If it has not changed (or changed 0,5 ppm or less), then you are good. If it has changed, then something organic is in your pool and consuming it.
Okay, thank you. That’s very helpful.
just in regards to what people were saying about the sand - my partner says he looked in the filter and the medium looks more like clear glass than sand.
 

Saturn94

Bronze Supporter
Mar 11, 2015
1,279
SE Virginia
Pool Size
20000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
Okay, thank you. That’s very helpful.
just in regards to what people were saying about the sand - my partner says he looked in the filter and the medium looks more like clear glass than sand.
That sounds like some kind of sand substitute some people use.
 
Thread Status
Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.