It would be interesting if one could create a system for geo HP water that only treats the water while the system is off. Ie, just before the HP turns off, some chlorine (or acid) gets injected at some upstream point. The chlorine then kills any existing bacteria and prevents new ones from growing. Treating all of the HP water (ie, while it is running) sounds expensive (but maybe not). A similar concept is a drainback system where all of the pipes drain back into the well (or out the drain) when the system is off. My guess is that iron bacteria wouldn't do well when getting dried out now and then.

What about simply adding a UV light to the source water system with an active charcoal or carbon cartridge filter to remove the dead bacteria which would otherwise become slime or residue in the system? Minerals on the other hand, are a different story. This is probably best applied to closed loop systems to maintain them bacteria free.

For open loop where ferric iron is a problem, a peroxide dosing system could be installed, which would leave no harmful residual, and the only byproducts are water, oxygen, precipitated iron and dead bacteria. The water could then pass through a charcoal filter to remove precipitated iron and dead bacteria, and could set up to automatically backwash periodically.

Arkie, would you be willing to conduct an unscientific experiment on your filtered and unfiltered water?

Draw one gallon each of your filtered water and un-filtered into clean jugs, add 8 drops of 5% chlorinated, unscented bleach into each jug, wait an hour or so and see what color, if any, the water turns...

Last time I checked many years ago, I only had 1-2 ppm clear water iron coming from my well. I've never had any issues with the iron slime / iron bacteria. I don't have any evidence the iron is making it through my sand filter. But this would all depend on how much water your are trying to push through the system. You have to give the ferrous iron sufficient time to oxidize and form ferric iron allowing it to precipitate out of solution and get trapped in the sand bed. As far as the iron bacteria goes, you might be able get rid of it by shocking the well with bleach. The following link and imbedded links have some discussion on that.

http://www.health.state.mn.us/divs/eh/wells/waterquality/iron.html

The sand filter plan sounds effective. I could see an ICF version....add in a chlorine injection, or Hydrogen peroxide or ozonator to the spray water, or a chlorine tablet, although problematic getting a proper mix with tablets, all are possible.

A simple color chart for detecting iron could be a good thing to develop for an engineer out there. (8 drops of bleach in a gallon of water and compare the color to a chart)

How to waterproof icf?

Sand filters for swimming pools have a backflush cycle, but this seems like a bare simple method, KISS theory applied.

No backflushing needed in this system, but how is the maintenance chore? Do you just go over to HD or Lowes and get some clean play sand once a year? I guess that it couldn't be any harder than lugging firewood. How would you ensure the sand was not cat litter in a previous life. Or how would you know the mineral content of the sand??

This system seems appropriate for drinking water, but it doesn't seem right for the HP HX needs...Could work, but it seems the water just came through a filter of sorts, from the ground in my case, just anaerobic. Some systems may be using a open air system. The quality of sand Must be an issue. I might be inclined to just mine my own sand from my lot. But, if I have iron, ferric or ferrous, in my wet sand from my property, well I am just putting iron back into my drinking water system, rt? Maybe a zeolite type filter. At first I was thinking of a big cistern that had an injection system, filling up when the HP was on, then run the domestic through a commercial type filter with a shallow well jet, backflushing into the HX as needed...

Anytime the system is 'opened', it should be sanitized, rt??

Actually, cleaning the HX is not that big a deal and had planned for it. Mineralization would have been a different story.

Keeping water in the HX seems the way to go, which I do with a check valve at the well pump and with a solenoid valve at the HX.

To kill the bacteria on a regular basis, and or correct aggressive water, perhaps When the pump turns off, have a
power-off time delay relay
where a pressurized solution tank of bleach could inject something good for the HX to prevent corrosion and or bacterial growth?

have a power-off time delay relay where a pressurized solution tank of bleach could inject something good for the HX to prevent corrosion and or bacterial growth?

Sounds like it would be worth exploring. Cleaning a HX twice a day isn't an issue - as long as it is completely automated. With titanium, frequent cleaning isn't likely to hurt it. And my guess is that a few valves, a timer, a circulation pump and a dosing pump (or venturi) are going to be far less $ than switching to closed loop.

Posted By nooboo on 01 May 2013 02:01 AM

...No backflushing needed in this system, but how is the maintenance chore? Do you just go over to HD or Lowes and get some clean play sand once a year? I guess that it couldn't be any harder than lugging firewood. How would you ensure the sand was not cat litter in a previous life. Or how would you know the mineral content of the sand??

For drinking water use, you shouldn't just use any old sand because you don't know what else might be in it.  I would be most concerned with heavy metals such as lead.  I purchase ANSI/NSF Standard 61 certified and labeled sand specifically intended for water filters.  The last time I replaced the sand in my filter, it cost ~$60 for enough sand to essentially replace all of the sand.  It comes in big brown paper sacks at ~100#/sack for ~$15 ea.  I get it from a local water well driller that also supplies water well and filtration equipment.  I believe this same sand is used by the local municipal water supply for filtration.  I'm sure they get it at a substantial discount from my price since they buy it by the truck load.

I've considered rigging up some type of backwash setup, but never really got around to it.  I give my old iron clogged sand to my mom.  She incorporates it into the soil around her rose bushes.

It would be interesting to put some of that iron slime in a glass of water and see what effect different acids and bleach have on it. Thinking more radically, circulating water with some type of mild abrasive powder in it might remove it (aka water blasting).