Color of water and Mustard Algae

[ned8377]

What color is the water itself supposed to be when you have Mustard Algae? I have green water but when it settles to the floor it puffs up easily into a yellowish cloud but I have green water and can't see the drain 10 feet down. So, what color is the water supposed to be if you have mustard algae? I've had green before and know that the water is green and can be almost black if it is bad. I've been told by a neighbor that what I have now could still be green algae and have the same characteristics of puffing up into a yellow cloud. Thanks.

 

[Texas Splash]

Green algae usually floats in the water and turns the entire pool a murky green. Mustard algae is a yellow green color and grows on the walls and floor mostly on the shady side of the pool. Pollen and dirt tends to accumulate in drifts on the floor in places with slower circulation and can often look fairly similar to mustard algae. There are occasional exceptions to all of these rules, green algae sometimes grows in mats on the walls or floor, mustard algae sometimes floats in the water, etc., so positive identification isn't always easy even for the most experienced pool person.
You may also wish to review the MA page at Pool School - Mustard Algae. You'll notice however, that regardless of which algae it is, inevitably the same initial treatment applies ... SLAM via Pool School - SLAM - Shock Level And Maintain.
If you have any more questions, please let us know.

 

[duraleigh]

Can you post test results? We are just guessing without them.

 

[ned8377]

Can you post test results? We are just guessing without them.

Ok here are the test results as of this morning:

FC 9 Last night at 6 pm it was 12.5. I had raised it to 18 ppm yesterday morning.
CC 0.5
PH 7.5 I lowered it to 7.1 before beginning the shock yesterday morning. It had been close to 8.0 ppm.
TA 80
CYA 30

Brushed twice yesterday and this morning. Going to the store to get more bleach and raise it to about 19 probably and keep it there by sunset. Would that be too high with a vinyl liner?
Here are some pictures.

Can't see the drain at deep end.

Deep end.

Deposits this morning after brushing last night around 6 pm.

Entire surface has a layer since 6 pm last night that can be brushed into a cloud.

 

[Texas Splash]

Great pics! I particularly like the ones of you brushing-up that green cloud. Definitely looks like algae. Mine used to do that before TFP. As long as you are sure about that CYA (30) from your own test kit, then the proper "SLAM" FC would be 12. Going much higher really doesn't help much unless you're going to be away from the house for a while. Continue to check your FC often, make sure you everything as noted on the SLAM page (link below), and don't stop until you pass the 3 SLAM criteria and you should do fine.

 

[ned8377]

So, what if the CYA is maybe 40, I would need to raise it much higher.

How high can you raise the chlorine in a vinyl pool?

Does it look like green or mustard algae? The water is green. The dust is yellow.

Thanks.

 

[Texas Splash]

The SLAM FC level for a CYA of 40 would be an FC of 16. As long as you maintain the correct ratio of FC to CYA as noted on the Pool School - Chlorine / CYA Chart it is safe for your vinyl. Is it MA? Hard to tell. But even if it is, you still perform a normal SLAM first, pass all 3 criteria, than after that (for 24hrs) elevate FC to a MA level for just 24 hrs.

 

[duraleigh]

ned8377,

It is VERY confusing for you to ask the same question in different threads. Please keep all your info and future posts under this thread.

So, what if the CYA is maybe 40, I would need to raise it much higher.

higher, yes, but not much higher. So what is your CYA 30 or 40? Are you following the SLAM article in Pool School?

 

[ned8377]

How could I possibly get an accurate CYA when I can't see the bottom of the pool? The last time I checked it, it was between 30 and 40 and I'm guessing it has come down slightly in the past two months since I checked it.

 

[Texas Splash]

Ned, I can't comment on the validity of the kit you are using for CYA testing, but when we use the TF-100 or Taylor K-2006 (mixing bottle and skinny tube w/ black dot), the test is accurate +/- 10 ppm. We can't over-emphasize the importance of an accurate CYA test since it drives your FC level. So if you getting a reading of 30-40, it's best to error on the side of caution (for CYA) and go with the higher number when doing a SLAM. So you'll want to keep the FC at 16. Will CYA lower over time? It can if there was a relatively large change of water. Evaporation alone does not reduce CYA. So stick close to an FC of 16 and continue to follow the other instructions on the SLAM page and you should see very good results. Hope this helps.

 

[duraleigh]

How could I possibly get an accurate CYA when I can't see the bottom of the pool?

I guess you are saying the pool water clouds the test and skews it.

1. Get a sample of pool water and put it in the view tube....there is less than a 5% chance you will see any cloudiness so you can perform the test normally

2. On the outside chance your pool is cloudy enough to register what looks like maybe 10 ppm, simply subtract 10 ppm from the test and you are good to go.

 

[ned8377]

Thanks Texas Splash and Duraleigh!

I've got a TF-100 and a K-2006. I started with the TF-100 and found that the CYA test is very subjective so ordered the K-2006 also from TF Test Kits just to double check. Turned out to be the same but still variable and subjective. So, it was two months ago when I checked it last and don't remember thinking it could have been over 40 ppm.

Anyway, the water is very cloudy and can't see the drain 10 feet down. That is why I was saying I would not be able to see the dot at the bottom of a tube accurately. Seems like it would disappear too soon and make me think my CYA is higher than it really is. I'll do a CYA tomorrow. There is less settling now after I brush twice a day though so maybe it is getting better. I added a clarifier/flock tonight. Maybe that will help. The water is not really green but more of a bluish color.

Thanks again you guys! This website has been very helpful about a number of problems I've had. I've only been in this house two years and never had a pool before.