Pond Boss Forums INTRO Questions & Observations Anyone have any ideas on filtering out precipitated iron from well water for ...

trout culture in a pond?

I know this may be out of the realm for most of you, but I would like to find an economical efficient way to filter out precipitate iron from my well water before it goes into one of my trout ponds. I'm hoping that someone has some experience with this or knows someone that does.

I understand the chemistry of it -- (water comes out of the well crystal clear, but when it gets exposed to oxygen the iron precipitates and becomes visable). The problem is this iron irritates the gills of especially brook trout, causing stress and possible disease problems.It's also not attractive in a small pond (water is murky brown).

From my research I have found some options are:

1.) Slow trickle iron filter (really expensive for the 45 gpms I pump)

2.) Water softener. Also really expensive for the amount of water flow.

3.) A set up with alternating layers of filter material and sand and gravel receiving the well water by gravity into a tank after aeration (I'm leaning toward this one)

4.) Biomass material or stone in the tank that the iron sticks to before going into the pond.

5.)Holding the freshly aerated well water in a pond to allow the iron to settle out before pulling it off the surface into the trout pond. (Not an option in summer as the water would warm up by the time it would reach the trout pond which is counterproductive.)

6.) Lining a large pit with sand and gravel in which the recently aerated water is dumped into, and once flowing through the material it is pulled off the bottom and into the trout pond. The problem I see with this option is, at some point the material will have to be excavated and disposed of which could be a problem.

Anyone know of anyone else with this problem and what they did?

Hey Cecil, your numbers 3 and 6 sound like pretty close to the same general 'filtering' idea, and from your list are the only feasibly economical ones I think. For number 3 you could rig up a layer system inside something like a large drum or garbage can with alternating layers of gravel and sand perhaps with a screen of some type between the layers. You should be able to run the water through that for a long time before worrying about changing or cleaning the material... and it would also aid in aerating the water as a side benefit. (Get a large garbage can with wheels... make it easier for cleaning etc... pump the water in the top then plum an outlet in the side at the bottom below the 'filter' media.)
Unless you can find something that readily attracts the Ferrous Iron like you mentioned in idea number 4. You could also chlorine shock the well and then use a carbon filter to get the chlorine back out.

you can also let the well water run down through a series of screens such as 1/4" hardware cloth to drive off the iron content of the water plus aerating the water at the same time.

Steve,

I think it would take more than just screens. I'm already running the water through a 5 foot packed column (gravity drop) that aerates and on which the iron clings to.

I believe I will try alternating filter material, sand, screens and gravel after the packed column, and sandwiching this in the poly tank it runs into before heading for the ponds.

Cecil

Hey Cecil, I have done some research since my last reply and now for sure I see the alternating filter media as the only really viable idea. I have found a few other commercial ideas involving chemical treatment and or 'attractive' filter media but they would bankrupt you in no time flat with the amount of water you are flowing. I did find a very large, very expensive looking stainless steel filter of sorts, (Almost looks like a precipitative purifier in concept) but with what you are planning for filtering I think you are better off. Is your packed column becoming clogged with the iron? If so you might want to put the filter before it if you can.

Thanks Pottsy. I haven't taken a look at the inside of the packed column yet, but I'm sure the media is coated somewhat. I have the well shut off for as now as it is cool enough and I have taken over 200 pounds of trout out of the 1/10 th acre pond. I may do what a nearby hatchery does. They soak their media once a year in muratic acid which cleans off the iron.

Running a filter before the packed column would be useless.That's because the water comes out of the ground crystal clear with no D.O. and the iron doesn't precipiate until it makes contact with as little as .15 ppm of oxygen iron per ppm of iron. It's the action of the packed column that adds oxygen to the water, so a filter only after that makes the best sense.

I'm going to revamp my packed column anyway so I will let you know the results.

I was thinking that you can add enough O2 to the water before it gets to the filter if you plumbed it in front of the column and made an O2 input or sorts to get the iron to react. Make it so the water falls down into the filter container from the top then you can have air holes on the top of the container around the inlet where air would be drawn in by the venturi effect of the falling water. Somewhat similar to my idea of a packed column but the bottom would be your filter media.

I have quite the interst for YOU !!! First a little background... Where I live.. There is a small 320 acre lake about 100 feet from my front door (it's across the street).... a river on the north and east property lines, a small 100'x 60'x6'deep pond about 40 feet from my back door... I have some kind of artisian well on the north side of my property about 30 feet from the river, and about 20 feet from my pond... Unfortunately the water from the well in my yard..and for that matter the well that feeds the house is SOOOOOOOOO RUSTY !!!! I had to have a water softener installed just to drink and bath with the house water!!! At any Rate the water coming out of the well turns from clear to orange as the air hits it so My idea of running the cold well water into the pond is OUT! Until I came up this pretty good idea... I bought a 100gal Stock tank(for cows and horses) and filled about 3 inches of the bottom with Gas Grill Lava Rocks. I installed a realatively large aquarium aerator in the bottom of the stock tank without an airstone... on top of the lava rocks I used some window screening and used old couch seats(the 4"-6" foam without the cloth coverings)on top... I notched out one end of the stock tank as they are oval-ish-rectangular to act as the water drop like a waterfall... the water is pumped in at the bottom of the tank on one end with a small water pump...the water riases through the "filter material" (lava,foam)and spilles over the opposite notched end much much better than if it came directly out of the well itself... then when the material gets irony a little pressure washing of the lava and I replace the dark orange foam... works pretty good...

Hello Cecil I like to use a method that might sound crazy but seems to work.The iron is alot easier to filter after it has hit oxygen an started to rust.You can use a cheap filtering system from walmart for about 12$just have to pump it into a metal holding tank and filter the water going to the pond If you want to get really clean water attach electricity to the tank and watch what happens.Gota go for now good luck DOC