Our water utility has turned off the Iron Filter ...

[koilover]

for 3 weeks for repair. What affects would this have on the koi?

What precautions should I do once the filter is back on line to insure no harm is done to our koi?

[MikeM]

Lori: Need some more information. What is the level of iron in the water that will be coming from your tap? What is pond temperature? Where are you located (to let us know type of climate)? What is pH and alkalinity level of your water? .... All of these things can influence either how iron will act or how to respond while waiting. If your water service has informed you that the water will be safe for human consumption, then most likely your koi will do acceptably, although you may want to minimize water changes. It may well be that your koi experience no adverse impact, and that you just have mildly brownish water for a while. On the other hand, if you have been advised not to consume the water during this period, I would heed that warning when it comes to the koi. If you are in a cool climate, you may be able to delay or lessen water changes more readily than if you are in a warm climate. If you decide to minimize water changes, then you should minimize feeding to help maintain acceptable water quality. You may observe some rusty staining of concrete, but a liner pond would be unaffected. I expect you will have very healthy algae in the season ahead, since iron is often a limiting element in the pond environment.

NOTE: Where I live "iron water" is really "iron-sulphur water" coming from shallow wells with high levels of hydrogen sulfide. The "rotten egg" smell can be light or heavy. If you can smell it, the water should not be used in the pond. Heavy pre-aeration in a separate storage facility can produce acceptable water, but the effort involved may be too much in your situation for just a 3 week period.

Good luck! I'm looking forward to hearing more about your situation.

[PapaBear]

More info about your tap and pond water would be helpful. If the iron content is extremely high additional holding time to allow the water to "breathe" will definitely help if water changes are needed. Even dissolved iron content will oxidize and settle in a holding tank to a certain degree which will partially offset the problem. If the iron content is high enough to discolor your tap water greyish or brownish as Mike mentioned you will be amazed at the amount of oxidized sedimentation in your holding tank.

[marco]

Hi Lory

May be the biggest problem won't be for the koï but for your filter, iron could destroy part of the biomass in the filter.
I would try just to feed a little less then usual and if you'r not overstcked, I would change the less water as possible.
Good luck
Marco

[bekko]

We continually contend with large amounts of iron in our spring water. As soon as the water is exposed to air, the iron precipitates and becomes non-toxic. There is staining and precipitated crud to deal with. The worst part is the iron-loving bacteria which grow on the precipitate. Its becomes a mass of orange/brown slime which can clog filters. The fish do not seem to care or show any sympathy for our plight.
-steveh opkins