Chemists: What prevents rust in a sprinkler system?
 

Anybody that has a lawn sprinkler system which feeds off of a well instead of the city supply knows that rust stains will eventually form on your house, deck, sidewalk, fence, etc. You can try to aim your sprinkler heads in such a manner as to minimize contact with hard surfaces, but due to wind and overspray you'll eventually have ugly rust stains on your house. The usual solution to the problem is to install an exterior 30-gallon tank which feeds an anti-rust chemical into the line so that it mixes with the well water and somehow neutralizes the iron before it exits the sprinkler heads, thereby preventing rust stains from forming.

Here's the catch: the anti-rust chemical runs about $10 per gallon, and for a large yard and well water with a high iron content, the $$$ adds up VERY quickly. I've searched high and low to try and find what the active ingredients are in the anti-rust mixture, but I've struck out. I have a sneaking suspicion it's a combination of very common and very cheap ingredients which the $10-a-bottle company doesn't want you to know about, or else you'd simply make your own anti-rust juice for a fraction of what they're charging.

So chemists, what's your opinion? What do you add to your sprinkler system to prevent rust but not kill your lawn and landscaping??

Many TIA..........

a lack of O2 or iron....

Well, I can't remove the iron from the well water and I certainly don't have any control over the O2, so how do you neutralize the iron? I'm guessing there's something that bonds to it and prevents it from turning to rust just long enough for it to fall on my grass and absorb into the ground...????

What if I place a giant magnet on the PVC to attract the iron before it exits the sprinkler heads?

Hey, it works on the oil drain plug.....right?

Very interesting system -- I'll take a look at that.

Thanks Rick!

Or you could simply let the damn grass die and save a lot of money

I'll run that by my wife.

Probably go over like a fart in a space suit.....:)

I have a well just to water my yard. It is hard water. It must not have much iron because I have no rust stains at all, just white calcium deposits on the areas where the water gets the most overspray.

The iron is in solution and a magnet won't work. Try using CLR to cleanup after the fact.

use PVC piping.

Hmmm, did you read his post about the magnet?

Anyway, Hugh, it's not about attracting FE particles, it's all about molecular alignment.
And after you get one of those magnet thingys, get a Cool Collar.

I install water treatment for customers all the time

The type of equipment depends on your level of iron (every well is different)

You need to have your water tested to see how many ppm (parts per million) you have and also what kind of iron it is

I have been treating water for over 15 yrs and iron is by far the hardest thing to treat for, it could be as simple as a standard water softener (cheapest) or may require a chlorinater system ($$$)

My sprinkler system is entirely made out of PVC or plastic. Hard to get it to rust...

Your not reading his problem

Ahh, did not see the "tank issue"... sorry.

Dry pipe systems are a good way to go. :)

You must have a "shallow well". Iron content in well water is variable depending on depth of well. Not everybody who has a well has iron. I bet you could re-jet a new well at a different depth - and get away from the iron issue. Or achieve less iron in your well water.

Now you can't just use the same spot the existing well is in. It would have to be at least a few feet away - preferably at least 5' or more away.

Have you talked to any well drillers in your area? I've jetted wells myself in neighborhoods which have iron issues and my wells worked great and did not have iron (to any great extent anyway).

I usually go down about 20' but you should measure your well depth and try to go more shallow.

The basic idea is to precipitate the soluble iron into hydroxides. This can be achieved by using an oxidizer such as hydrogen peroxide. Then, the insoluble iron either stays at the bottom, or can be filtered. That is how oxidizing filters work.