Water Softeners and Air Filtration Systems - Getting iron our of irrigation water in Central Florida

I would appreciate any help as I am investigating a solution for our neighborhood.

We live in a neighborhood where everyone is on a well with homes on 1-1.5 acres of land. For our in house service almost everyone has some kind of water treatment system.

The problem watering the lawns the water is high in iron and stains the sidewalks, sides of houses, fouls the solenoid valves on the irrigation system, etc.

Of course the water softener companies want to put in a gigantic system on each house. I think this is a terrible solution because of the cost of salt, maint., putting salt on water.

We will need to get everyone’s water tested. For comparison sake, our water is as follows:

12-13 GPM from our pump
7.5-8 Ph (Central Florida's aquifer percolates through limestone and I would expect everyone's water to be basic).
1 ppm of Iron, soluble

Everyone runs their sprinklers about 6 hours 2-3 days per week in the summer.

I've read about Berm, Pyrolox, MTM, and even a company that makes Terminox filters. Which would be best for our wells and application?

I like the idea of a filter that backwashes and is fairly maintenance free.

As an aside, how do I get the iron out of the irrigation pipes?

Thanks in advance.

We install many softeners for people who don't want soft water usage outside and, yet, have high iron which stains sidewalks and other items from the irrigation systems.

What we do is install polyphosphate feeders. These are chemicals that sequester the iron keeping it from coming into contact with oxygen and preventing staining. There are food-grade phosphates so toxicity is not an issue.

These will work and they cost much less than iron filters or softeners to solve that particular water treatment dilemma.

Contact time may be important so having a liquid feeder or tank with self-sacrificing cystals large enough must be factored.

Andy Christensen, CWS-II

Andy, thanks for the reply. Will the polyphosphate feeder work well for the larger amount of watering we have to do. We are all watering at least .5 to 1.2 acres of land.

I did a search on Google and most companies were suggesting polyphosphate for lower volume, cold water (which we have) and where bacteria is not a concern (and who cares for our irrigation water).

Good question.

I have never done an irrigation system that large. There may be a point of deminishing returns and an alternative, say backwashing iron filter, may be better.

Would rust deposits be an issue for the whole area or just a small, visible section?

You would need to estimate maximum gallons per day and study the ratio of contact time and phosphate feed capacity.

The manufacturer would be better suited to give you those details. Sorry, I could be more help here.

I will look into it for better details soon.

Andy Christensen, CWS-II

Andy, thanks for the assistance. I was leaning towards a backwashing filter.

I'll have to do some calculations and timing for the water usage. It's pretty big with 6-7 rotating heads per zone and 7 zones. According to the rotating sprinkler head manufacturer, the flow is between 2.6 and 3 GPM. That's a staggering 8000+ gallons per night. I'll have to run a test to see what the flow rate of my pump is (because I was figuring 12.5 GPM and the sprinklers may be pulling 21 GPM).

Looks like a job for the weekend!

I have to rerun my flow rate for the pump. I mismeasured my bucket by 20% and my pump is getting around 16 GPM. Which will work for any of the backwashing filters.