Suspect Black and Mustard Algae

Jump to latest Follow Reply
S

Silva1181

Silver Supporter
Apr 9, 2019
194
Houston
Pool Size
14200
Surface
Plaster
Chlorine
Liquid Chlorine
Good Morning, since last week I noticed yellowish staining on one of the steps and thought it was pollen, even though I have no pollen floating on the surface. I brushed it away and when brushing I could see the cloudy residue in the water. The yellowing did not go away completely even after brushing and scrubbing. After brining my FC and PH in line the yellowing faded away by the next day. I usually add a half gallon of LC daily and I do realize this is not the way to handle maintenance without checking my levels. Yesterday, on the same step the yellowish staining reappeared but now it also appeared on the opposite side of the pool on the other step. I don't see any yellowing on the pool walls. I also noticed the formation of black algae along the tile line in several areas. I've dealt with black algae before and was able to get rid of it. I suspect the yellowish staining is mustard algae since we don't have any more pollen in my area. The area of the staining doesn't go away completely.

In a panic I poured in three gallons of LC and kept the pump running all night. I realize now that I should have checked all my levels before adding so much LC, but again I didn't give it a second thought. Plus my testing supplies are over a year old and the four little containers of my FAS-DPD turned black so I assume it's no good to use.

Two questions:
1) To any members in the Northwest Houston area, near Spring, TX that may know of a company or person who maintains pools following the TFP recommendations, please let me know. I want to turn the maintenance over to someone since I continue to fail with the maintenance due to my busy work schedule, travel and not having anyone else at home to help.

2) The pool water looks clean and clear but is it safe to use the pool if in fact there is black and mustard algae present. I ask because I have family visiting this weekend with kids who will want to jump in, but I will close the pool if it's not safe.

I appreciate the help and advice. These are photos from this morning

pool staining 3.jpgpool staining 2.jpgpool staining 1.jpg
 
Last edited:
There are no companies that follow TFP, it would cost you at least 300 a month for a service to come every day...

I would recommend you change over to a Salt Water Generator.. It will add chlorine on a daily basis and once you set the levels and get it going you can go a week without testing... It really is a great way to take care of a pool and will work perfect in your situation...

Now order a new refill kit and get to testing your water.. DO A SLAM this weekend as you can still swim in a pool being SLAMed.. and order a SWG :)

An RJ 45 or 60 would fit your pool perfect, the good sale is back on.. order the 30 and get the 45.. :)

Best Sales, Rebates, Deals, and Promotions | DSP

www.discountsaltpool.com www.discountsaltpool.com
 
Thanks. I talked to a pool maintenance repair person who has handled multiple repairs. He suggested I use a power washer to help remove the algae, if in fact that what I have, which I really don't know. I went to work this morning and was able to remove 95% of the staining including what I suspect is black algae.

I won't likely get new agents until next week so I can either take water to the pool store to test or buy testing strips to at least know my levels. If my FAS-DPD is grey/black is it not reliable for a FC test? Since I added so much LC before checking PH or CYA, how do I deal with these levels, as I understand they affect my slamming levels?

Thanks,
 
The FAS -DPD should be just fine until you get the new stuff.. :)

You need to find out what your FC level is at...

Please do not use the pool store or guess strips...
 
These are my levels as of 5 minutes ago. Since yesterday, I added 5 gallons of LC 10%.

FC - measured at 10ml / 28 drops/ so I am at 14 and according to the SLAM chart, with a CYA likely below 20 I should SLAM at a FC of 10.
TA - 100
CH - water turned red after adding drops and indication of Calcium Hardness? Then it took 26 drops to turn it blue again 260.
PH - well over 8.2 but I know the reading is not accurate due to high chlorine. Should I add MA?
CYA - is below 30 because I can still see the black dot filling above the 30 mark. Should I try to increase CYA?
 
Last edited:
raise your CYA to 30.. SLAM at FC 12 for 30 CYA

During a SLAM only test FC and CC as the high chlorine can skew other tests..

Do not add MA until FC below 10 and you can test PH.. :)
 
sorry to ask, but how do I test for CC, I don't see the instructions in my kit. I used to access How To Videos from a pool source website, but I don't remember the name of the company.
 

Enjoying this content?

Support TFP with a donation.

Give Support
ok, i followed the instructions in the video using the 25ml mark.

FC - 2 scopes of FAS-DPD - 34 drops of R0871 to clear the water, multiplied by 0.2 = 6.8ppm. I have no idea what this means. I then added 5 drops of R0003 to see if the water turned pink again and it didn't, the color remained clear.

Is my CC ok or do I have an problem?
 
Thanks. I managed to get my CYA up to 30, by placing the stabilizer in a sock, in front of a jet since this morning

I redid the FC test using the 10ml and it dropped to 5, so I just added another 149 oz of LC to bring it back up to 12. I have direct sunlight for about 8 hours or more of the day, so I know the sun is burning up the LC quickly as well. We're in for more rain and I know this will affect my CYA due to fresh water. Will check everything again this evening and in the morning. I plan to keep my FC at 12 for now.

I am hoping to let the kids use the pool this weekend, but we'll see.

Cowboycasey and Mknauss thank you for helping me through this process! Have a great July 4th.
 
Good Morning. I did the OCLT last night and to my disappointment the results were not good. At 6:45 pm yesterday evening, with no sun hitting the water, I tested FC and it had dropped to FC8, which I expected since my pool gets so much sun. Since my CYA is 30, I added LC about 90 oz of 10% LC according to poolmath to bring it up to FC12 SLAM level. I waited a 1/2 hour, then re-tested the FC, CYA, CC at 7:15 pm, no sun on water:
FC -18 - using 10ml = 36 drops of regents to go from dark pink to clear = FC18. Here's a photo of my FAS-DPD powder which I noted previously is grey. I've had two containers stored in a dark cool cabinet for a few months but they don't last long before going from white to grey? I was shocked to see my FC was 18 considering I only added LC according to pool math. Could my FAS-DPD be giving false readings? I bought new FAS from Amazon and should receive today. I read there's a liquid version of the FAS-DPD, should I buy this instead?
CYA - 30
CC - 0

At 6:30 am this morning these are my numbers with the pump running all night.
FC - 13 - huge loss of FC
CYA - 30
CC - 0

I will continue to keep my FC at SLAM level throughout the day and do another OCLT tonight. It's getting expensive to buy this much LC, but more importantly it's getting difficult to find LC. Home Depot, Lowes, ACE do not have any in stock due to shortages. Walmart has it in stock and is limited 2 gallons per day. Luckily, we've been able to get more then 2 gallons. My final resort if the box stores run out is to buy it from the local pool supply store which charges a lot as well. I don't have ladders, spa's or anything else in the pool where algae can hide. I am unable to remove the light fixture due to corroded screws, so I can't see behind it. I scrubbed, and power washed around the water line and steps. The water is crystal clear and clean, no haziness or anything, very frustrating. What to do, if my OCLT continues to show losses?

FAS-DDPP.jpg
 
Last edited:
The R9870 should be fine. If you have any of those little desiccant packets around keep the R0870 container in a plastic bag with the packet(s) in there. It is moisture that gets to it.

Tonight, if your get a FC of 8 or above for the OCLT, do not add any more chlorine. Just use that level overnight. Takes away the adding/mixing/testing error.
 
If you additions are "off" I suspect you may need to recalculate the size of your pool.
For our area, a SWG is a great addition to a pool on reducing the hassle of buying and feeding daily chlorine. I regularly go on business trips and come back to a sparkling pool. Mrs. Beard does not do pool maintenance.
 
Thank you both. I tried multiple sites to calculate my gallons, but none of them had my pool configuration so it was a bit difficult to get the exact gallons, so I ended up going to a pool store in 2018, provided the measurements and they provided me the gallons.

Do you mind telling me if my pool size/gallons is wrong based on my dimensions. THANK YOU!

I am referencing the 1st photo from top to bottom, width measurement taken from inside edge to edge.
- The top end measures 12ft / 8" in width is 3 ft deep
- The center measures 18ft / 9" in width is 6 ft deep
- The bottom end measures 15ft / 9: width is 3 ft deep

pool 1.jpgpool 2.jpgpool 3.jpg
 
Last edited:
Assumptions: Pool is 3 feet deep in the outer areas. For the sloped area to the deep part and the deep part, I assume an average of 5 feet deep.

I averaged the width to 15.75 feet x 32 feet long and 3 feet deep, and then subtracted the four corners using an average diameter of 14.25 feet.

For the area deeper than 3 feet, I took the middle circle at 18.75 feet at an average depth of 2 extra feet.

Volume = 1890 cu feet = 14,140 gallons. Add in piping and equipment, 14,200 gallons.

There is a test method using measuring pH and then adding a specific volume of Muriatic Acid and then measuring pH again. You could also do it with powdered shock. If you do it with shock, using the 25 ml FAS-DPD test for most accuracy.

A Chemical Way of Calculating Pool Volume

There is a way to use pool water chemistry to calculate pool water volume without using the traditional geometric calculations. The geometric formulas are fine for pools that are traditionally shaped. However, when pools do not fall into these convenient shapes, a chemical method can be used...
www.troublefreepool.com www.troublefreepool.com
 
  • Like
Reactions: cowboycasey

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply