Did I Mention That Iron Filters are High Maintenance?

[LLigetfa]

Not just the iron filter but also the micronizer, HP tank, AVC, and contact tank before the filter. Iron filter was replaced in 1019 at which time the micronizer, HP tank, and micronizer were cleaned. Two years later, I had it cleaned, more FilterAG media added, and a contact tank added.

Now the micronizer needs some love, the AVC stopped working, and volume/pressure drop across the iron filter indicated it needed cleaning. With all this media being driven up into the top basket, I wondered if some of it may have broken into small enough pieces to go out the drain. If the amount of freeboard had increased enough and if inspecting the bottom basket showed iron fouling, I was contemplating topping it back up with a little Katalox Light.

Whenever the head is pulled, the dip tubes comes up with it and reseating it requires washing down the bottom basket which is best done outside if there is a chance it will overflow. I installed an RV blowout plug on the water line going to the iron filter so that I can use air to dewater the media tank, so there was a chance the wash-down could be done without overflowing the tank. None the less, we took it outside to be safe.

The head and the top basket were badly fouled with iron. Taking the head apart to clean it could not be done without damage so it needed some new parts. The bottom basket was not very dirty so we just hit it with the pressure washer. The amount of freeboard had not changed so no KL was added. The installation of the dip tube hold-down should make it easier to pull the head next time. I will post pictures later.

When we installed the contact tank, we also installed a modified AVC in it as a backup to the AVC in the HP tank. What can happen is if during the iron filter backwash, the pressure drops due to the constriction imposed by the micronizer, and the AVC fails or simply cannot remove the quickly expanding air volume, some of the air moves forward into the contact tank. Since we shortened up the second AVC by a foot, that AVC should remove the excess air preventing it from moving forward into the iron filter. If/when the second AVC fails and air moves forward into the iron filter, it generates a violent boiling action that drives the media up into the top basket. Without a top basket, the media could be driven up into the head.

If/when I am near the HP and contact tank, I check on the AVCs by looking where the water level is. I also constantly record the pressure and periodically review the recordings. A clogging iron filter will have a weak backwash which then does not overdraw the micronizer/drop the pressure. If I have not stayed on top of it and air does move forward into the iron filter, I usually notice either a loss of pressure due to the top basket being clogged, or I can hear the sound of water splashing as it passes through the air trapped at the top of the iron filter.

 

[Reach4]

I think Ditttohead suggested to not use a top basket on an iron pump, but to either use an umbrella type diffuser, or to use nothing. I went with nothing when I changed out my media. My top basket looked pretty clogged.

 

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[LLigetfa]

I already explained that if air moves forward into the iron filter during backwash it creates a violent boiling effect that will lift the media up into the head. I would rather periodically remove the head and clean the top basket than have to deep dive into the head to clean it. My old iron filter did not have a top basket and I frequently had to take the head apart to clean the passages. The media I lost to the drain is another issue and media stuck in the valves would prevent them from closing which demanded immediate attention.

After today's work I took note of how much air was in my (quasi*) contact tank. I then ran a backwash on the iron filter and see there is more air in the contact tank than before, so obviously air moved forward from the HP tank to the contact tank. If/when the air volume increases in the contact tank due to a non-functioning AVC, it will obey the same law of physics as it did on the HP tank and move forward into the iron filter.

*I say quasi because a true contact tank would not have any air and so have no need for an AVC.

These Flexcon/WellMate HP/contact tanks and AVCs are designed to hold more air so that they have similar drawdown to captive air tanks. Essentially the tank is almost empty when the pressure drops to kick-in so if it is drawn faster to where the pressure drops well below kick-in, the air escapes with the water, moving forward. This can also happen with a working AVC as the AVC is designed to let the air out very slowly, too slow for the fast expanding air. Sure, I could do the same thing to the HP tank that I did with the contact tank and shorten up the AVC so there is a foot more water and subsequently a foot less air but that reduces the drawdown considerably.

Obviously, I need to get on top of the non-functioning AVCs which is part of this thread topic. As long as the AVC is in working order, this would not be an issue. Replacing the two AVCs is next on my to-do list. I have two spares, a short and a long one but I've been procrastinating as I need to pull the tanks one at a time and take them outside to pressure wash them out. I made up bypass pipes with unions so that I can pull one tank at a time and still have running water for the pressure washer.

 

[LLigetfa]

Because the micronizers are also high maintenance items, I have two of them plumbed in parallel with double union ball valves so I can switch over to one while I remove and clean the other one. Today I removed the one that is out of service to clean it with muriatic acid but first I removed the metal bypass valve. After cleaning it when I was putting the bypass valve back in, I applied too much torque and cracked the plastic body so will have to replace it. Good thing I have two so the other one is still working.

 

[LLigetfa]

I applied too much torque and cracked the plastic body

My tale of misfortune continues...

I contacted my water guy about purchasing a replacement Waterite Micronizer and he did not have new stock but did supply me with a used unit. Once bitten, twice shy, seeing how fragile the Celcon body material is and seeing pump plier jaw marks on it, I thought I would be safer to just grab it by the unions I attached to both ends with which to thread them on.

That did not go well. The twisting force on the Celcon body material cracked it. I am sure I put more force on the original micronizer that is more than 25 years old so I am at a loss as to why I have so much misfortune.

I noticed online that Waterite makes two models of micronizer, the blue Celcon body and the black Kynar ozone resistant one. I am wondering if the muriatic acid I used to clean the two broken ones may have weakened them. I also wonder if the black Kynar body is stronger.

 

[LLigetfa]

Here is a pic of the parts that were replaced on the iron remover head. The iron deposits on the parts has dried and shrunk so it doesn't look quite as bad as when they were removed.

 

[LLigetfa]

I also wonder if the black Kynar body is stronger.

The black one has all stainless steel parts so that alone is worth the higher price. I have one on order.

When installing it, I will make sure to use a large enough Crescent wrench so that the wrench flats reach corner-to-corner. The flats on a 12" Crescent come up short and so can apply pressure in the wrong place. Also will place the spanner on the side I am threading on the fitting so as not to twist the body.