Anyone Know What Causes This?

[Jimrahbe]

Anyone know why the exposed parts of this eyeball turned brown?

Only the part that is exposed to the sun seems to be affected. Yet the brown will scrub off with a cleaner.

All three eyeballs did the same thing. The eyeballs at my other two pools do not have the same issue.

I installed them in an effort to get better directional flow, but was less than impressed, so they have been removed.



Thanks,

Jim R.

 

[mknauss]

I get something similar but a bit darker color. I suspected it was some minor metal staining coming from fill water or even some of chemicals we use.

 

[Jimrahbe]

Marty,

I did not think about metals, as I use city water..

I'll have to check that out.

Thanks,

Jim R.

 

[JamesW]

Probably iron. Try vitamin C.

If you remove the SWG cell, look upstream and downstream of the cell to see if there's a difference.

Iron gets oxidized in the cell and there will be a noticeable difference in iron stains in the pvc past the cell.

 

[Jimrahbe]

James,

I'll give that a try..

But.. the problem seems to be outside the fitting and not inside the fittings.. I will check the inside of the SWCG pipes, but I don't remember seeing anything inside the pipes at the returns.

Thanks,

Jim R.

 

[atttech-2]

looks like the same sunburning the vinyl parts of my RV get over time. Painting the RV parts fixed the problem but I doubt that is a viable solution for a part that is submerged in water 24/7 and subject to friction when the eyeball is moved around. I bet some manufactures have better UV protection than others.

 

[Jimrahbe]

A,

That is what I first thought, but it scrubs off.. It "appears" to be a stain of some kind.

I'm going to run some metal tests in the next day or so...

Thanks,

Jim R.

 

[JamesW]

Put the fitting in a glass of water and drop in some vitamin C to see if the stain goes away.

 

[mknauss]

The fittings I have that darken are not effected by ascorbic acid or muriatic acid. Most of it will wipe off except the drain covers. Those I cannot get clean.

 

[Flying Tivo]

Happens to me too. I also thought it was UV burn. Following with interest.

 

[Jimrahbe]

@JamesW

The stain went away when I soaked the fittings over night in a container of water and vitamin C...

Does the Vitamin C test mean I have iron or metal in general?

Thanks,

Jim R.

 

[JamesW]

All pools have iron. It's just a matter of how much.

 

[Jimrahbe]

James,

What I know about chemistry you could write on the head of a pin... I did a little reading and is seems you can capture iron, but you can't get rid of it. Then you have to keep capturing it..

Is there a way to capture it and then get rid of it?

Thanks,

Jim R.

 

[mknauss]

If it oxidizes in the water, you can filter it out. High pH will cause it to do that.

My niece in Houston has iron in their city water. So I have her use polyfill in the skimmer to strain it out of her small ABG pool. Water starts green, turns blue a few days later.

 

[JamesW]

You can sequester it or you can try to get it to filter out as noted above.

For it to filter, it needs to be oxidized so that it becomes insoluble.

The cartridge will get some of it.

I haven't used polyfil, but it sounds like a viable solution.

Ideally, you would try to put something downstream from the salt cell so that it gets trapped after the cell where the iron is most likely to be oxidized.

Putting a cartridge filter downstream from a SWG cell or ozonator can be effective, but you would need to offgas the hydrogen or ozone at the filter top for safety.

Tabs can be placed in a skimmer to introduce chlorine before the cartridge filter to try to oxidize the iron before the filter so that it precipitates on the filter.

Don't put tabs in the skimmer if you have a heater.

Keep the pump on continuously while tabs are in the skimmer.

Only use about 3 tabs if you use tabs and turn off the SWG.

 

[Jimrahbe]

Thanks guys,

A couple of great ideas..

I'll report back what works for me.

Jim R.

 

[JamesW]

Iron is mostly a nuisance. It doesn't hurt anything except the appearance.

It really depends on how much you want to get rid of it.

I would start with the easiest and least expensive things first.

If necessary, you could do an ascorbic acid treatment and then drain and refill assuming you could get mostly iron free water.

Some places will rent filters for iron that can be used to fill a pool or you could get trucked in water.

Some places will do whole pool reverse osmosis.

Ozone is not practical for most situations.

Maybe if you really wanted to get rid of the iron, it would be worthwhile getting a corona discharge ozonator and a mixing and degas vessel before the cartridge filter to oxidize the iron immediately before the filter. But, I don't think that most people would want to invest in that.

Sequestrants are effective in reducing the staining rate, but iron will eventually stain.

Ascorbic acid will remove the stains, but it's a continuous cycle.

With careful chemistry management, iron can be kept under control for months before it needs to be treated again.

 

[JamesW]

You could put a cartridge filter downstream from the SWG.

That's where the iron is most likely to be oxidized.

You don't want to put it in front of the existing filter because it would get clogged with debris.

So, you would need a second cartridge filter.

I would want about 20 feet of pvc pipe between the SWG and the second filter so that the chlorine gas would have enough time to fully dissolve into the water.

I would put an automatic degas valve on the top of the second filter so that the hydrogen gas doesn't accumulate and become a potential problem.

Most likely, this isn't a practical solution, but it's an option if you want it.

 

[dmk]

My pump strainers also turn brown over time. Hadn’t thought much about it, figured it was from chlorine over time.
I’ll check my return fittings in the morning.

 

[JamesW]

Next time you remove the cell, look in the pipe before and after the cell.

You will usually notice that the downstream side is significantly more stained than the upstream side.

Iron gets oxidized relatively easily. Once it gets oxidized, it precipitates out on the first thing it touches.