Little brown rust spots on fiberglass pool...

[JoyfulNoise]

The kit is basically a series of different chemicals for diagnosing stains. They are dry acids and dichlor powder. The purpose is to see which chemical has the greatest impact on the stain. Dichlor removes organic stains. Ascorbic acid removes iron. Sodium bisulfate removes calcium scale and sulfamic acid is good at removing copper and cobalt stains. Based on which one or combination of chemicals work, Jack’s Magic then has a program that you can treat the entire pool with.

If the stains are only in the deep end, you’ll have to make up something like a poultice using a nylon to hold the powder and then use your pool skimmer pole to hold it against the stain. It’s much easier to do these determinations in the shallow end and when the water is warmer. You may want to simply wait until spring when the water has warmed up enough. I doubt the problem will get significantly worse.

 

[tfpusername]

Thanks for all the good advice guys, I think I will hold off on the stain id kit until it warms up a bit.

I did have one other thought - you asked about a heater, and like I said I don't have one, but it did get me thinking - I have been leaving my Maytronics Dolphin bot in the pool 24/7 (only take it out to empty the basket). I think the first spots started appearing a couple months after I got the bot...

So follow up quesiton - is it possible my robot caused the spots? If so, is there any chemical treatment I could just try (as long as it's cheap/won't hurt anything)

 

[JoyfulNoise]

Your robot definitely is not the cause of any stains.

 

[toofast]

Your robot definitely is not the cause of any stains.

So I'll be watching this thread I have a few small stains that I thought were my imagination.... obviously won't get it till the spring but hopefully we can figure this out.

 

[tfpusername]

** UPDATE 6.10.18

Ok been super busy but the weather is warm and I finally had time, so the stain kit is on the way. Unfortunately there are even MORE brown spots (now along the corners of the shallow end). These new spots seem lighter (thought they were just settled dirt at first). These new spots seemed to have started appearing after I got my new variable speed pump and put in brand new filters (maybe it's not filtering enough?)... Hopefully the stain ID kit can provide a solution.

One thing I remembered - My CYA used to be very high (80+) so you guys told me to stop using the chlorine pucks. Over the last yer my CYA seems to have dropped back down to around 50, so I tossed a puck back in the floater. Other than that the levels have been perfect (I dump in one gallon of bleach a week and ONCE in the last year I had to add some muriatic acid to lower the ph. Could the drop in CYA have anything to do with the spots?

Will let you guys know once the kit gets here.

 

[Texas Splash]

The CYA is not the cause of your stains either. In fact, your statement about adding a gallon of bleach once a week seems a bit low to me, at least in the summer. My pool is slightly larger than yours sure, but I go through a 1/2 gallon a day (2.5ppm of FC) in 24 hrs. The pump or filter wouldn't have anything to do with it either. You noted that the stains seem slightly lighter now which would indicate the stains could be organic in nature and simply need more time for the chlorine (and scrubbing) to finally go away. Now I didn't go back through the earlier part (page 1) of your thread, but it's important to watch your CH level as well. Not because we as FB owners worry about etching like a plaster pool when the CH is too low, but for protection from certain stains. If your CH is currently at least over 100, I doubt that's the problem, but I didn't go back and look. The stain kit should help considerably. Once you receive it and do the tests, please post a full set of water numbers to the new post as well so we can put this whole scenario together and try to help you with a plan.

 

[ka8yiu]

Keeping my CH at 300 and not 250 like I used to seems to help my stains.

 

[tfpusername]

Sorry again for the delay, ok did some tests and it looks like I need to get my PH and chlorine stable before I use the Jacks Stain ID kit. PH was pretty high 7.9+ so I added some acid (aiming for 7.2-7.4 right?).

My Chlorine total/free was also low 1ppm, I know one gallon of bleach a week isn't a lot, but I do a pretty good job running my robot/cleaning filters, and currently I'm the only person swimming (maybe a couple times a week), so I thought I could get away with a minimal amount of chlorine. Perhaps it's worth it to just bump up the chlorine massively (3-4ppm at least?) and see if it has any effect on the stains...

Total Hardness has always been high (around 500). I have yet to do a CH test, I will do one of those (I'm sure its high).

CYA 40 (was 80+ last year but since I stopped using the chlorine pucks it has come down). I started putting the pucks back in (one a week, to maintain the cya).

TA also high 180...

Once I get the chlorine and ph within range I will try the stain kit and report back... Thanks again for everyone's feedback/support!

 

[mknauss]

Your FC is dangerously low. See [FC/CYA][/FC/CYA]

 

[tfpusername]

Ok got my chlorine to around 3, and my ph to 7.4. However my total hardness still seemed high (500) so I did the CH test (tell me if I did it wrong…)...

Filled my Taylor test tube (big side) up halfway (25 mark). Then added 20 drops of r10, then 5 drops of r11 (turned pink), then counted drops of r12.

At 43ish drops of r12 it started to look purple, at 45ish it was definitely blue. So is that 440 CH?

The water here in Vegas is pretty hard, I imagine draining/adding water from the tap won’t do anything (water coming from the garden hose is likely very hard). What’s the best way to reduce these numbers?

 

[JoyfulNoise]

Did the blue color stop changing at 45 drops? The test ends when the color STOPS changing, not at the transition point. So your CH is 440ppm as long as the blue color stopped getting more blue.

 

[tfpusername]

Hard to say exactly, but let's assume 440ppm.

What is it supposed to be? And most importantly, how do I bring it down to that level?

 

[JasonJoel]

Hardness is a strange thing. The right number depends on what kind of pool you have, and whether you can control the CSI or not.

Many people have to run their hardness in the six or seven hundred (or more) region due to local water quality.

 

[tfpusername]

Ok so a mid 400 CH isn't a big deal then? Is the water 'stable' enough to try the jacks stain kit?

 

[toofast]

I just wanted to add to this thread that I have these very similar sounding issues problems spots.

My chemistry is always been perfect and I never worried about CH once I saw the spots I tested CH which was 50 I bumped up to 150 with no apparent changes vitamin C or pucks do nothing.

Not sure what to do next but this is a relatively new pool and the manufacturer is not willing the comments yet it appears.

Those photos are from a 6ft depth best I could do.... and they're only in the deep end close to the main drain circulation should be very good.

Standing by with anything I can do to help both the original poster and myself

 

[tfpusername]

Yeah those look like my spots. Also at the deep end (6feet).

So I am heading to the pool store today, is there anything I should get to try and prep the water, or should I just go ahead and try the magic stain ID kit now that the chlorine/ph are good at least (although I am not expecting this stain kit to tell us much).

 

[toofast]

Yeah those look like my spots. Also at the deep end (6feet).

So I am heading to the pool store today, is there anything I should get to try and prep the water, or should I just go ahead and try the magic stain ID kit now that the chlorine/ph are good at least (although I am not expecting this stain kit to tell us much).

So Strange...why in the deep end only...insane.

I have no advice, other than you are a few steps ahead of me trying to fix.

 

[tfpusername]

Ok I think I have a serious calcium hardness problem. I have been noticing it is taking more and more bleach and muriatic acid to keep things at the right levels. There is now what looks like brown scale/mineral deposits appearing and they wont brush off.

The other day after adding some water (we lose about a couple inches a week from the heat) I tested my water and the CH was almost 1000. The tap water around here is insanely hard I guess.

So how am I supposed to lower the CH? I read that the 'pour in' solutions don't work, and the only way is to refill with fresh water, which I COULD do (since it evaporates so fast), but I need a way to lower the CH in my TAP WATER now too...

*this "flocculant" is the stuff I was told to use to 'break up the deposits and lower the CH"

https://www.amazon.com/Swim-Super-Floc-Water-Clarifier/dp/B002WKSARQ?SubscriptionId=AKIAJ2WSQIQLDL22FHMA&tag=swimunive-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B002WKSARQ

Worth a shot?

 

[toofast]

Looks like there's not a lot of experience to help us out I'm going to try fighting again with the pool manufacturers see what they say

 

[Household6]

I had similar (not sure if it was the same) issues a few years ago. Can’t recall exactly what it was or how I fixed it, but long story short, it turned out to be metal in the water that had caused the spots. Figured this out by putting a vitamin c (I think) tablet on a spot and seeing what happened.

Might want to look into it.