White fiberglass pool is beige coloured below waterline

[dborn]

Hi all,

This is my second summer with a new all white fiberglass pool. It was installed in June and closed in late-September last year. Pool was closed by the pool company. During fall, winter and spring enough rainfall and snow filled the pool back up so I didn't have to add any water to it when I opened it.

The pool is surrounded by *many* trees and this spring, I litterally removed several cubic feet of wet leaves from the top of the pool winter net. After opening the pool, whenever I shocked it for the first few weeks, water would turn lime-green for a few days before returning to normal (not algae green, more like "kool-aid green"). I had the water tested for metals and phosphates and none were found. So I used the pool all summer and everything seemed normal after that. As time went by, I started noticing a light brown-green ring just below the waterline (so I thought) but the water seemed light-blue throughout the pool.

I just had the pool company come by this week to close the pool for the winter and now can see clearly that the entire pool has a very even beige tint everywhere that was under water compared to the few inches above that are still white as it should be.

The colour seems a little darker close to the water returns and a little lighter close to the skimmer at the other end of the pool. Also, inside of the skimmer there is no beige tint...

I have just found the subject of tannin staining in pools. Could it be that? Will it go away on its own during the winter? (I wish...) or if not, what can I do to remove it? Silly question: can ozone stain a pool? I have an ozone generator (and a chlorinator that will be replaced by a Stenner pump and liquid chlorine) and noticed that the clear plastic tube used at the ozone injection point into the pool plumbing has turned to a very opaque and dark colour after its second summer of use.

The pool is now closed and will remain so until next April, so at this point it's mostly curiosity but if my story rings a bell to anyone, I'd be interested in hearing about it. Note: the beige tinted fiberglass seems normal in all other aspects, it's shiny and I tried the vitamin C test and also a light scrubbing with a plastic scouring pad and it did not change anything.

I'm really glad I found this site and forum, I'm learning so much on the subject of pools and their maintenance but still have a some way to go.

Thanks for any help,
Daniel

P.S. Pool chemistry: My CH was a little higher than I wanted thanks to faulty readings from my ColorQ, around 320-360 according to two pool stores. PH usually in the 7.6-7.8 range and ALK in the 100 range. I tried lowering the PH in the 7.4-7.6 range and ALK around 70 towards the end of the season to try to avoid the MA-sodium bicarbonate "yo-yo". CYA ranged from 0 to about 60 now (due to trichlor tabs). Sorry for the long-winded post, tried to provide a complete picture.

 

[amyj1952]

I have a White Fiberglass pool that had brown stains all over it. I went to my local pool store and purchased Ascorb-X which cleared the stain up completely. I was going to close my pool today, so last night we put in our Algacide and Shock. This morning the entire pool is once again stained. Can someone help me with this problem? I do not want to close my pool with the stain there. HELP!!!!

 

[dborn]

Is it a uniform stain throughout or rather several stains surrounded by no stain? Is it only on the bottom or sides?
In my case, it seems to be very uniform, kind of beige everywhere but not in the skimmer (no sunlight?)

In my case, I didn't really notice until I had the pool closed as it is uniform. I could see a slight "ring" when water moved up and down but did not realize it was everywhere until the water level was brought down.

 

[Swampwoman]

From your description I believe you have iron staining, or possibly copper -- both will colorize the water when you shock because they're being oxidized from the water, and then precipitate onto the surface. It's normal not to get a metal reading if the metal has already precipitated into a stain or been sequestered by using something like metal magic, which any pool companies do use on opening. But if you have metals and don't continue to add a maintenance level of sequestrate, it's effectiveness fades and then the stain will turn up.

In the case of the original poster, you'd be best to first test the stain using Jacks Magic test tablets to confirm. You could also just use a crushed up vitamin c to confirm that it's iron, but sometimes copper acts differently and can look like iron but the Ascorbic Acid treatment isn't the only option for copper, which sometimes benefits from a different stain remover.

In pool school, there's an article about how to do a treatment with Ascorbic Acid that should clean your pool right up. Note, however, that if you left ph ride around 7.6 to 7.8 as you mentioned in your post, the staining may reoccur. Metals require a lower ph.

With respect to the second poster, if you shocked at close, that is likely what caused the metal to come out of solution and redeposit the stain. When you have sequestered metal, there are a few things you can do when you need to shock. You can add a full dose, eg two quarts of jack's or metal magic. You can also add a filter aid if you have sand -- some iron will filter out (but not all, ime).

There is also a product that I haven't tried during shocking that from testimonials would appear to help floc and remove the metal called ferritabs -- google it -- it's sold be the ok guy.net I believe.

So far, I suspect it may be most effective if your water has a tint, meaning the metal is oxidized. I tried an experiment with it to see if it would remove iron that's already been sequestered by meta magic and it would appear not to e effective under that condition.

Hope that helps! Best wishes!

Ps - sources for iron are usually well water. Fir copper, sometime an algaecide used has it, or parts of heater can start to deteriorate. Iron is also found in fertilizer, etc., so it's theoretically possible that landscape drift from when the pool was open added the iron.

 

[dborn]

See, that's the thing. The first year, the pool was filled by a professional service. Had no problems either. Second year (this year), pool was topped up by rain & snow and nothing else. I didn't use any algaecide nor any fertilizer on the lawn. The pool is far from the neighbours (at least 30 feet all around) and even from my lawn. Aside from a truckload of leaves that soaked in the pool (on top of the cover, not directly on the fiberglass) for a while, I really can't see anything else...

I tried the vitamin C tablet (not crushed though) straight on the fiberglass and not even the slightest sign of lightening up was seen. Also the pool doesn't have any separate stains, it's just an even beige tint...

I guess I'll try Jack's Magic test tablets and see.

Thanks,
Daniel

 

[Swampwoman]

Have you tried acid or a puck in a sock? If it's tannin, chlorine should lighten it.

But the water being clear green earlier this year is still suspicious for metal.

 

[dborn]

By acid, do you mean muriatic acid?
No, I haven't tried anything else but what was stated earlier.
What I'm doing now, is to remove leaves on top of the winter net every week so they won't accumulate like they did last year. I will buy the "Jack's magic stain ID" in the spring and also a TF100 test kit and probably a metal testing kit too.

If it turns out to be tannin staining, could I keep the pool at a chlorine shock level for a few days and it might clear it out? I figure it should...

 

[Swampwoman]

That should work. What doesn't clean up then normally will with a season of sun and good sanitation.

 

[dborn]

Apologies if this frowned upon but just in case this may be useful to anybody else with the same problem, I've posted a follow up of my ongoing saga with stains in this other thread: http://www.troublefreepool.com/if-metals-make-water-green-will-they-make-cc-high-t59037.html#59037

Follow up on my story:

I kept shocking the pool until the green was all gone. Well, it was metals because then my fiberglass pool was a stained brown mess. Poured in some metal stain remover/sequestrant from the pool store (figured I had nothing to loose) and lo and behold, the pool returned to it's glorious original white and water was clear.

After three weeks of not adding anymore sequestrant, water was back to lemonade green!
Poured in some more sequestrant (only half from the first time since the fiberglass wasn't stained yet) and now it's back to nice and clear.

Currently trying to filter it out with a submersible pump and a MetalTrap filter http://www.askalanaquestion.com/METALTRAP.htm
Sure hope no one is going to tell me that these things don't work...

 

[Swampwoman]

Dborn, I've been looking at those METATRAP filters but unsure how long the resin lasts and if suitable for my 22,000 gallon. Are you performing regular iron testing to see if indeed it is removing the iron from your source water?

I am also now using my softened water for top ups instead of outdoor unsoftened (had a faucet ext. attached to system.) Of course, in a heavy fill, this would require regeneration pretty quickly.

Thanks for the info and cheers!

 

[dborn]

I got the 25,000 gallon format for my 40,000L/10600 gallon pool so I'm hoping it would last me for this year's use and next year's. I'm planning to filter the water using a submersible pump at every pool opening in case the metal additions are airborne since we live close to a sand quarry and I know our well water has some manganese, from professional water analysis. We do have a water filter on the house and it keeps our water smelling and tasting ok. Now I will also top up over the summer using the MetalTrap filter. This filter is huge, expensive and heavy but I hope it also works! (I should know within a week or two if my water turns green again or not, when the sequestrant runs out).

I've been topping up the pool once in a while since we got it 2 years ago through the house water filter but I don't figure we've put in so much water from the well and the metals should be minimal (?)

According to the MetalTrap literature, it's rated at 1ppm metal for the gallonage so if you figure you have more than 1ppm, you'd need to get a bigger one than the 25,000gal.

I've tested my pool water with the Taylor copper and iron test kits and they register 0ppm! Of course, I don't have a manganese test kit so I'm not sure there. But for sure, there are metals in my pool water.

Right now with all the rain, I'm not topping off the pool from the tap so I'm just concentrating on getting rid of all those metals from the existing pool water. I really don't want to be buying and putting in all that metal sequestrant every week for the rest of the summer (and every year).

If I empty and refill the pool, I have two choices: filling it back up with the well water (will I be right back to where I am now?) or hiring a professional service to fill it up like we did the first year at $800 a pop! (not kidding). That's why I'm trying really hard to save our existing water (on top of the ecological aspects).

 

[Swampwoman]

Yeah, now I remember...even through the softener at one point I was getting 1.5 ppm in my fill...and it's much higher straight from the well. I think that's why I never moved forward with MetalTrap.

I ran out of Jack's by mistake last week. Am awaiting a shipment. And in those few intervening days, my steps are pretty discolored considering I haven't even been shocking. I would love to kick the jack's habit once and for all

 

[dborn]

You could still use the 25,000 gallon filter but at 1.5ppm it would only be good for about 16500 gallons. That's still alot of topping up.
Unless you plan to completely refill your pool through the filter, it would be sufficient for quite a while I would guess.
They say that for higher PPM values, you need to run the water through the filter at a slower pace and it's got a nice ball valve right on the filter to adjust it.

My submersible pump is supposedly good for 1000+ gallons per hour but all I'm getting through the filter is about 110 gallons per hour so it should require 4 days to run all the water through the filter!

I figure I want to let the water run through it for about two passes since I'm pumping from the pool and returning it right back. For sure, after 1 pass, I'll still have some water that will never have been through the filter. I hope that little submersible pump will enjoy running 24/7 for a week!

 

[cborn]

I posted this on another thread but found this one which seems to match my issues too. I have had similar problems the last few years. We are on a well. I had to drain and fill the pool 2 years ago. It is a 6500 gallon fiberglass pool with a cartridge filter. Water turns green unless I add Asorbic Acid. So need help on exact steps to either control or get rid of metals. Leslie's pool water tests showed FC 1, TC 1, Hardness 200, CYA 45, TA 80, Ph 7.2, Copper .6 Iron 0 and Phosphates 200. Water is cloudy but starting to clear after one week of running pump. A silt like substance settles on steps and on the bottom. After vacuuming and cleaning the filter, it was filled with same substance. I added 32 oz of Metal Free over 2 days. I added a little Vitamin C and where i dumped it the water cleared immediately. any additional help is appreciated.