Question about Algae

[setsailsoon]

Folks,

I've been doing the TFP method all of 6 weeks so far with great success. But I'm noticing weekly a very slight amount of greenish algae in a few 1' diameter spots and barely visible. You can't see it on a photo at all. When I see it I run my PoolCleaner and it's gone in a few hours. Other than this my pool is perfectly clear. I've kept within range on all the tests (see below) only my CYA has been low. We departed the house for 3 weeks so in preparation I raised the FC to 16.5 ppm with liquid chlorine, pH went up to 8.4 and was adjusted back down to 7.4 in a few hours with a split dose of muratic using the Pool Math tool. I also loaded the chlorinator with 5 trichlor tablets and a lowish setting of 1.5 out of 5 that seems to be sufficient to keep chlorine levels adequate in normal operation. Each time my filter pressure drop increases a little over 1 psi I clean it with a comb-hose cleaner. This is where I can confirm I'm getting green algae. The filter has what I'd call a light coating of this plus a little sand and dirt. It cleans off very easily and the filter lasts about 2 weeks before I see the pressure drop increase slightly. I'm running the pump 10 hrs per day which should be giving about 3-4 turns per day (based on pump curve and discharge pressure).

I live in S Florida and we get a LOT of sun and a lot of rain (short bursts). The solar heater alone gets the pool around 88 each day. So here's my question about algae: Should I slam any time I see any algae? I've got a feeling I may have to be doing it all the time if that's the case as there is a swamp behind my house that continuously "inoculates" the pool with algae via wind. Other than the green algae in the filter it isn't a problem. So I'm not sure if I'm on the verge of a green pool one day or if I'm seeing what I should expect in my situation. I should also mention we have a light load of my wife and I for an hour or so in the evenings and the pool is screen enclosed so we have almost no leaves etc. I'm hoping the consistent 0 CC reading and the two occult tests I've done with 0 readings(not shown below) indicate I'm OK.

I'd appreciate much if you experienced people here could just do a little "hand-holding" for this newbie that lacks confidence even though the pool looks perfect.

Here are my test results and actions:

Date	TA	CYA	FC	CC	CH	PH	Actions/Observations
31-Oct-15	130	<20	20	0	225	7.6
1-Nov-15	130	<20	18	0	225	7.7
2-Nov-15	100	<20	14	0	225	7.7
3-Nov-15	90	<20	12	0	250	7.5
4-Nov-15	90		8	0		7.5
5-Nov-15	90		7	0	250	7.6
6-Nov-15			4			7.8	Addded 16 oz muriatic acid 31.45%
6-Nov-15	80	<20	4	0	275	7.4	6 hr after acid addition
7-Nov-15	80	<20	2.5	0	300	7.6	Added 1 gal 10% Cl
8-Nov-15			14				Added .75 gal 10% Cl, 10 oz 31.45 Muratic Acid, 6 oz trichlor
9-Nov-15							Out of Town
10-Nov-15							Out of Town
11-Nov-15							Out of Town
12-Nov-15							Out of Town
13-Nov-15							Out of Town
14-Nov-15							Out of Town
15-Nov-15							Out of Town
16-Nov-15							Out of Town
17-Nov-15	90	20	3.5	0	300	8	added 20 oz 31.45% Muratic Acid
18-Nov-15			2			7.4
19-Nov-15			2			7.5	added 8 oz trichlor, tested after 6h w/pump FC 3, Ph 7.5
20-Nov-15			5
21-Nov-15	80	20	6.5	0	300	7.7	cut chlorinator back to 0
22-Nov-15	70	20	6	0	300	7.7	LOT of RAIN!! 2" OCLT FC=5
23-Nov-15			5			7.8	Windy, dry, and cooler
24-Nov-15			4			7.8
25-Nov-15			3			7.9	LOT of RAIN!!
26-Nov-15	70	20	2	0	300	7.9
27-Nov-15							LOT of RAIN!!
28-Nov-15	70	25	1	0	300	7.9	2 Trichlor Tabs set feeder on 2.5
29-Nov-15
30-Nov-15
1-Dec-15			5+			7.7	Robin tested
2-Dec-15
3-Dec-15
4-Dec-15	70	30	5+	0	300	7.8	Turned off chlorinator
5-Dec-15
6-Dec-15			5+			7.8
7-Dec-15
8-Dec-15	70	30	6.5	0	250	7.9
9-Dec-15
10-Dec-15			5.5			7.9
11-Dec-15			3			8	Added 12 oz Muratic
12-Dec-15			2			7.5	Added 2 tabs of Trichlor set chlorinator 3.0
13-Dec-15			5+				Reduced chlorinator to 1.5
14-Dec-15			5+			7.6
15-Dec-15	70	20	5	0	300	7.5	Added 4 oz Muratic early morning, tests 5 hrs later
16-Dec-15							Added 192 oz 10% Cl
17-Dec-15			16.6			8.4	Cleaned Filter, Addded 16 oz muriatic, 40 oz trichlor, Chlorinator 1.5, noon ph 7.4

 

[kimkats]

I am going to guess that you have an area of bad circulation in that area.

Have you done an OCLT? Pool School - Perform the Overnight FC Loss Test (OCLT)

Please do this and let us know what it says.

I am thinking it might be a good idea to do a SLAM just to see if you can get any algae out and gone for good.

How often do you brush your pool? I have found when my husband does not brush the sides of the pool it starts to get algae there.

Kim

 

[ewkearns]

The fact that you see *any* green means you have a green pool. How green might be arguable. Your chlorine is swinging wildly, which means you don't have some part of your regime dialed in correctly. Your pH, also, seems out of control. Perhaps you should test more often and strive for more uniform levels of chemistry

 

[Casey]

Welcome. Couple things I'm seeing is your low CYA. If you're getting a lot of sun and your pool temp is 88*, you should probably increase the CYA and raise the FC to work with the CYA. Look at the chart in Pool School.

Next is adjusting pH with an FC over 10ppm. You should never do this as high levels of FC give a false reading of pH. In the future, adjust pH only when FC is under 10ppm.

Now, the spots of algae... how many times a week are you brushing your pool? If you're not, you need to start. It's probably one of the most important things a pool owner can do that doesn't get done enough and running an automatic cleaner or hand held vacuum doesn't count.

An OCLT will help determine if you do indeed have something growing. My best educated guess is, you dont have enough chlorine, dead spots and not enough brushing.

 

[setsailsoon]

I am going to guess that you have an area of bad circulation in that area.

Have you done an OCLT? Pool School - Perform the Overnight FC Loss Test (OCLT)

Please do this and let us know what it says.

I am thinking it might be a good idea to do a SLAM just to see if you can get any algae out and gone for good.

How often do you brush your pool? I have found when my husband does not brush the sides of the pool it starts to get algae there.

Kim

Kim,

Thanks so much for the reply. I've done the oclt a couple of times and it was always zero. The first time was Nov 22 and most recently 3 days ago. That greenish stuff on the walls happens to me too, only a few small spots and mostly where the afternoon sun hits the pool. It brushes off very easily. I basically brush any time I see the spots on the bottom or on the wall. Maybe once a week or so. When I get back to the house I'll do the slam but I'll be gone 'till first week of January... I just hope I don't have a green pool when I do. What do you think about my chemical levels for a 3 week absence?

The fact that you have the green on the walls does relieve my fears a little. Thanks for the help, again!

Chris

 

[setsailsoon]

Not dialed in at all! Seems like I just get it close then I have to leave for a week or two so I goose it up on Cl then the next day pH is up so I fix that then I'm out of town for 1-2 weeks (just left today for 3 weeks). I'm really amazed the pool looks so good. Being so new to this I'm sure I wouldn't be too consistent even if I was there all the time but the travel is downright frustrating.

The thing that's confusing a little to me is that when I look at the criteria for being complete with a SLAM is that I seem to meet them already. CC has never been above 0, OC is 0, pool water is clear... in fact it's gorgeous. But there is some green albeit only a very small amount on the floor.

Chris

 

[tim5055]

If you see algae then it does not count as clear water. Clear means no visible algae, dead or alive in addition to the clarity of the water.

 

[setsailsoon]

Welcome. Couple things I'm seeing is your low CYA. If you're getting a lot of sun and your pool temp is 88*, you should probably increase the CYA and raise the FC to work with the CYA. Look at the chart in Pool School.

Next is adjusting pH with an FC over 10ppm. You should never do this as high levels of FC give a false reading of pH. In the future, adjust pH only when FC is under 10ppm.

Now, the spots of algae... how many times a week are you brushing your pool? If you're not, you need to start. It's probably one of the most important things a pool owner can do that doesn't get done enough and running an automatic cleaner or hand held vacuum doesn't count.

An OCLT will help determine if you do indeed have something growing. My best educated guess is, you dont have enough chlorine, dead spots and not enough brushing.

Casey,

Very helpful, thanks! I usually adjust the pH after I goose up cl in prep for an absence. I'll wait for the FC to come down from now on. And Kim mentioned the brushing also. I bet I'm not brushing enough. I'll try to pick that up when I get back as well.

Thanks much!

Chris

 

[setsailsoon]

Tim,

Now that's clear (no pun intended!). Seriously your definition leave no wiggle room and I definitely need to slam.

Thanks.

Chris

 

[MarianParoo]

The November OCLT results (F=5 comment in particular) is questionable. Your other OCLT was done at maintenance levels. I suggest that you take it to shock level and try it again.

- - - Updated - - -

Lotsa cross-posting here!

 

[setsailsoon]

Marian,

I should have mentioned that reading as it's confusing. I actually tested the night before and FC was 5. As you can see the next day was 5 as well giving OCLT of 0. It's been that way each time I checked it and for some reason I didn't record them. Most recent was Dec 15th. The pool is definitely in for a SLAM when I get back.

Thanks for the advice and for taking the time to look closely at my results... I get a little grief over "playing with my chemistry set" but I do find it interesting.

Chris

 

[MarianParoo]

The OCLT can a tricky thing. At low or high FC/CYA levels it doesn't always work that well. When anything is questionable, it is best to do the OCLT at shock level. What's a little bleach/liquid chlorine....???

Slam away!

 

[MarianParoo]

Are you going to be home for a while?

 

[setsailsoon]

Marion,
I won't be back home until 1st week of January. I'm hoping the regime I did before departing yesterday at least prevents green water before I get back. And either way I'll be doing my first SLAM. If nothing else at least I'll have a little practice with the technique.

Thanks for the replies and advice!

Chris

 

[setsailsoon]

Welcome. Couple things I'm seeing is your low CYA. If you're getting a lot of sun and your pool temp is 88*, you should probably increase the CYA and raise the FC to work with the CYA. Look at the chart in Pool School.

Casey, I've been trying to get the CYA up by using Trichlor as a part of my cl addition. Doing this has at least started to register some CYA but it seems to be very slow to increase. After my most recent add of 5 tablets I'm hoping this will work but if it doesn't I think I'll take a more aggressive approach and look for some conditioner or a product that has pure CYA in it.

Thanks again for the help!

Chris

 

[Patrick_B]

Increasing Cya from tabs when you start at a low level of Cya is impractical. Once you get close to where you need to be, it's much easier.

Your problem is simply caused by gaps in Free Chlorine Levels, and from never having killed all the Algae. It's really no more complicated than that.

 

[ewkearns]

CC has never been above 0, OC is 0, pool water is clear... in fact it's gorgeous. But there is some green albeit only a very small amount on the floor.

If you have green and CC is 0, that lends a lot of credence to the posters suggesting poor circulation.....

Even though you are under a roof and get little sunshine, you probably need to opt for more CYA. That said, however, you need to find a way to level out the amount of chlorine in the water at all times. You cannot calculate that your pool will use [X] gallons of chlorine over a 2 week period and dump that amount in, expecting the chlorine to hang with you in a linear manner (especially with a low CYA). Chlorine has a half life and early in your absence the chlorine has already tanked, allowing the algae to get a foothold.

Looking at the month of December and the chlorine levels of 5+, I assume you are using the OTO test, which is not your friend. At a FC level of 5+ (which includes anybody with a CYA of 50+) the OTO test only indicates presence of FC and tells you nothing about CC. You really need more detailed documented data. To that end, let me suggest this excellent tool: http://www.troublefreepool.com/threads/73298-Jesse-s-Graphical-Pool-Testing-Log-%28Excel-spreadsheet%29

What kind of chlorinator do you have? When do you run your pool pump? What time of day do you typically test?

 

[Casey]

Others may not come out and say it (maybe they will ) You more than likely will come home to green pool. We need you to get serious about this. The water behind your house has very little to do with your pool. It's a separate entity. Your main issue is lack of chlorine. If it's green, you have no chlorine. You have the perfect breeding ground for the green monster: sunlight, 88° water temp, and no protection. If you have a TF100 you should be using it.

We'll be here when you get back. No sense in having a fit over it now. If you have time while your away, you should read the ABC's of pool water chemistry in my signature along with the other links.

 

[JoyfulNoise]

Others may not come out and say it (maybe they will ) You more than likely will come home to green pool. We need you to get serious about this. The water behind your house has very little to do with your pool. It's a separate entity. Your main issue is lack of chlorine. If it's green, you have no chlorine. You have the perfect breeding ground for the green monster: sunlight, 88° water temp, and no protection. If you have a TF100 you should be using it.

We'll be here when you get back. No sense in having a fit over it now. If you have time while your away, you should read the ABC's of pool water chemistry in my signature along with the other links.

100% Agree!

The problem here is inconsistency. Inconsistency in testing and inconsistency in pool care.

CRB,

You sound like someone who has to travel a lot (either for work or family) and it sounds like you are not able to care for your pool on a consistent basis. It has been said before but I will repeat it - The TFPC Method of pool care requires daily attention to your pool. It may not be more than 5 mins/day adding some chlorine in the morning and testing at night, but your pool requires it if you wish to practice the TFPC Method. There are no shortcuts.

Given your schedule, I believe you should seriously consider either installing a Stenner pump to automatically deliver chlorine everyday or a salt-water chlorine generator. Either of those automation options would be far and away much better for you and your pool. I know it is a significant investment upfront to make but, as it is now, you are wasting your money having to constantly SLAM your pool and keep the chlorine high because you can not consistently dose your water. Honestly speaking, even hiring a pool service company to take care of your pool would be better than what you are going through now.

As Casey said, there's nothing to do about it at the moment and even if the pool is green when you get back it's not hard to fix. But I do seriously urge you to consider getting some kind of automation on your pool.

Good luck,

Matt

 

[setsailsoon]

Patrick,

That is really great to hear and very helpful. I'll SLAM when I get back and then try to make sure the FC level stays in range. I'll get the CYA up after I get it good and slammed. I've learned a LOT from this thread or maybe I should say it's helped re-enforce Pool School principles.

Thanks!

Chris