New Pool Since July

Yan

0
Oct 11, 2012
16
Houston, Texas
Our inground pool was just completed in July, and although my husband says "we," it's actually just "me" that is looking after the pool. I'm so glad I found this forum through Google.

The pool builder left me a Poolmaster Basic5 Test Kit, and most days, I've tested for Chlorine, pH, Acid Demand, and Total Alkalinity. (Why is it named Basic5 and test for only 4 things?) Anyway, I've ordered the Taylor Complete Kit and it's due to arrive this afternoon.

I've brushed almost everyday, I may sometimes miss one day out of 10. The water is always crystal clear, the readings are almost always in the Ideal range, except for pH sometimes running a little high, so I put in the amount of muriatic acid that the test says to put in. I've taken samples to Warehouse Pool to have tested about once a week to see if our readings match, and so far, they have. Their other test says the Calcium Hardness is Low, about 175, and to add 5lbs of Hardness Control, which I've done. They also keep saying that the Phosphate level is high, but the pool builder has said not to do anything about that. And I've read your forum where several people have said the same thing, that if the FC is good, it'll kill the algae that high phosphate encourages.

When the pool was first finished, the white plaster was pristine WHITE!! Then about two weeks later there was a small grey circle about the size of a dime on one step. Since then, about 7 or 8 such circles have shown up, always one by itself in various parts of the pool, no clusters. Also, the spillover spa does not have these grey spots, but the bottom does have brown stains.

The pool builder came back to look, said the grey spots are not algae, and the brown stains are just stains. He didn't give me any advice on what to do to get rid of them, just said it's an ongoing process. There are also some brown stains in the pool itself, they all look like how a dingy bath tub will look if no one cleans it. I can't take pictures now because the sun is shining on the whole area, and there's too much glare. Will do it later this evening. The grey spots and the brown stains do not brush off. I have also bought an algae pumice stone and a wire brush to brush, and nothing comes off.

Once a week, on Thursdays, I've set the SWG to Boost at 100% for 24 hours, like the manual suggests to do, normally it's kept at 60%, been running the filter 12 hours, this past week only 10 hours since it's cooler. We had a couple of cooler evenings last week, so have heated the pool to 88°F for a few hours only on those days.

What are these grey spots, and brown stains? I've read through the posts and at first thought they were algae, but from what I've read, and from what Warehouse Pool says, algae will brush off. These don't. I think this morning there were a couple more grey spots at the bottom of the pool, smaller than the size of a dime, making a total of about 10 spots.

I told my husband about the Vit C tablet, so what does he do? Two nights ago, he went and got a 2" plastic pipe, stood it on its end and kept the Vit C tablet on one grey spot overnight. The next morning, there was a 2" ring of brown around the grey spot! The grey spot is still there. We tried rubbing the brown ring off with the wire brush, it is lighter but hasn't come off.

Sorry this is so long. Please help! This is our first pool ever. What can I do about these 2 problems at the bottom of my pool?
 
Welcome to TFP :wave:

I think you may be experiencing mottling...below is a past thread on the subject from our deep-end section of the forum
gray-mottling-plaster-discoloration-t44424.html

Glad you and the PB decided to skip the warning on Phosphates...you are correct that phospates really do not matter as long as you maintain adequate FC vs your CYA level. Post up a set of numbers when you kit comes in and we can help you fine tune your chemistry. :goodjob:
 
Thank you for directing me to the link. So it sounds like there's really nothing I should do, or try to make the plasterer re-do. Like one of the people that posted said, in the sunlight, the pool looks beautifully sparkling clear. Anyone would love to swim in it. It's only at dawn and dusk that you can see the spots and stains. Since the Vit C tablet didn't work, it is definitely not metal?

My test kit arrived, along with the Salt Test Kit. Bearing in mind that I set the SWG to 100% for the past 20 hours, my readings are:

FC:17.5ppm
TC:0
CC:0
pH:8
TA:100ppm
CH:300ppm
CYA:40ppm
Salt:3200ppm

BTW--when the FC level is so high, will it do anything to my arm that is lowered into the water to get the water sample?
Also, in Pool School's article about SWG, it says, "The cell should be clear of debris and the plates should appear either black or metallic."
Where are the plates? I see only an about 12-inch long translucent green tube.

Thanks again.
 
With a swg CYA at 40ppm is a bit low. We generally recommend 60-70ppm on a SWG system. You will want to lower and maintain FC to around 4-6ppm. Turn off or lower the SWG to let it come down and there is no reason to run the swg at 100% at all. We usually advise that if superchlorination is required it be done with liquid chlorine, not your SWG as it will reduce the life of your cell.

PH at 8 may be a false high reading. Anytime FC is at 10ppm or above, PH will read falsely high...recheck PH as soon as FC falls below 10ppm. TA is a bit high, with your target being 60-70ppm on a swg pool, but it should come down on it's own as you add acid to manage PH.

Your arm should be fine, but if you want to be safe, rinsing with some fresh tap water can't hurt :wink:
 
Both the manual and the pool builder recommends putting the chlorinator at 100% once a week before an expected high bather load. So that's why I've been doing it on a Thursday, so it's ready for the weekend. You don't think I should do it any more? The rest of the week I've kept it at between 50 to 60% with a 12 hour run time. The 12-hour run time was set up by the pool builder when he first switched it on, but I've now set it to run for 10 hours because it's about 20° cooler in the daytime.

I'm not too sure about the spa. It is a spillover spa. I do, kind of, understand that it's a closed system, so technically, it's all the same water, but because of the higher temperatures and also the jets and blower, should I do things differently for it? The chlorinator can be set for both the pool, and the spa. Right now, I've got them set the same, figuring that even though it's a smaller space, its higher temps, and jets, etc, require the same amount of chlorine. Sometimes when we have the jets and blower on, I think I can smell chlorine, which from all that I've read, means there's something trying to grow in there.

dmanb2b Thank you, good to know about my arm. I have olive skin, and I don't think it has turned any lighter yet! LOL.
George N I can't really see anything through the green tube. I don't have to take it apart to see the plates, do I? Pool School is wonderful reading! My head spins, but I'm learning.
 
You are very welcome. Your FC is too high and it is because your SWG is putting out more chlorine than your pool and bather load requires. SWG operate best in maintaining a certain FC range. Major adjustments to FC, such as a planned part/increased bather load, is best done with some regular chlorox or chlorinating liquid. Running the SWG at 100% will just reduce SWG cell life span. We often recommend oversizing the SWG and running at a low percentage, which generally increases life span
 
Thank you for explaining how to prolong the life of the SWG. I thought I was doing the right thing by following the instructions in the manual, and from the PB. So, after the FC has come back down to the ideal range, I go to the Pool Calculator and find out how much liquid bleach to put in when we expect more swimmers?

Am I doing the right thing for the spa though? Should I pour some of the bleach into there too, or just pour it into the pool and let the water circulate into the spa?

I'm sorry to ask for such exact instructions. I am a step-by-step kind of person, and if I follow instructions, I am less nervous/confused about doing things. :-?
 
when the FC level is so high, will it do anything to my arm that is lowered into the water to get the water sample?
That's a common misunderstanding....it's harmless. When you put your hand into the water in your washer and you have added bleach, the FC approaches 300ppm and is unbuffered by any CYA at all.
 
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