Don't take this the wrong way but...... why are you asking this question here?

If I read your post correctly, you hired Culligan to solve your water quality problem and it hasn't been solved to your satisfaction. Since you PAID them to do this, why are you not complaining to them? Make this their problem because they are the ones who designed and spec'd the apparatus between your wellpoint and your taps.

They held themselves out as the Pros and would have tested your water in advance of doing anything. You should be getting MONTHS out of those filters, not days. Do yourself a favour. Call them up, tell them you are totally dissatisfied and you want the promised results that you paid for.

I agree, Culligan haven't installed a satisfactory system. Can I just point out, though, installing coarser and coarser filters may prolong their life, but you're just letting more and more sediment through.

I don't understand what a sandpoint is....can you explain?

I don't know much about water treatment (my dad the retired engineer does) but I'd think you would be better off if you could clean up where the water's being drawn from (if that's possible) and then maybe a settling tank or something like a sand filter, not unlike what they use for swimming pools, and, after all, municipal water systems, THEN the current installation.

I wonder also if reverse osmosis would work, if it could be backwashed like the sand filter - you can even get sand filters that backwash automatically.

What you need to do is remove the "gross pollutants" before the expensive filter. Another possibility might be a pre-filter, cheaper than the charcoal one, but still, the water must look like MUD to clog your filter that fast.

There are numerous ways to obtain water for a private system. You can dig, bore or drill a well. If ground conditions are right, you can even drive a pipe into the ground until it reaches water bearing strata which often consists of sand or fine gravel. The unit on the end of the pipe is a screened pickup. The pipe itself is plumbed directly to the pump. There is no well casing. The pipe is its own well casing. Check the PDF in the link below.

The screen on sandpoints are often quite course in order to keep from plugging up. If they do plug, you're screwed. You have to try back-washing them in the hopes of clearing the screen. If that does not work, you have to drive a new well in a different location but if the strata is the same all over your property, then it's only a matter of time before it happens again.

The course screen allows large particulate to enter the water system. Sometimes this is a temporary issue and it will clear itself with continuous pumping. Local well drillers are the best source of information regarding such issues and the OP should probably consult them. It could be that the only solution to this problem is to go to a different type of well that is deeper. She may need to get water from 80 feet or 150 feet or 300 feet below grade in order to find an acquifer that is free from the contaminants that she is forced to deal with currently.

In most places, you must disclose whether you have adequate potable water in sufficient quantity to meet the needs of the home being sold. If you lie about it, you can be sued successfully for all the costs associated with remedying the problem so it isn't something to take lightly.

The local health branch can condemn a house and put a stop to occupancy if there isn't proper sanitation available.

It seems to me that the real problem lies with the water-bearing strata that the sandpoint is pulling water from. There may be no end to the crud that is flowing past the sandpoint. There is no way of knowing one way or the other. She could hire a well driller to put a pump directly on the well pipe and pump it non-stop for a couple of days to see what comes out and if it is increasing, decreasing or constant. Periodic examinations of the residue left after pouring a five gallon pail of water through filter media will give you an idea as to what is happening.

Doing that should give the OP some clue as to what direction to go in. In the interim though, I would be hauling the local Culligan Man's butt back to the home to figure out WHY his solution to her problem isn't working. If he cannot produce what he originally promised then he should remove what he sold her, put her system back to the way it was previously and refund her money in full. The error was his, not hers. It's just that simple.

Here is a link that might be useful: sandpoint wells

A couple of questions, if you don't mind?

How big is the 'holding tank'? Gallons? If you are using a chlorination feed system followed by a holding tank, it should have a minimum of 20 minutes contact time for disinfection purposes. So with 6gpm, you should have approximately 120 gallons. What are the dimentions of the tank?

What condition is the filter when you take it out, meaning what color? Is the iron bacteria--a slimmy red gel or something more solid/powdery?

If the holding tank is too small in capacity or the water rate flow is too great, then the oxidized elements won't have time to function or settle out and they will pass on to the filter which clogs up very soon--as in your case.

Does your holding tank take water in from the bottom and pass out through the top? Or in/out at one end or the other?

You need a backwashing media filter (in place of the filter housing) containing gravel on the bottom and filter ag or some other filter media that can be easily backwashed and not affected by microorganisms.

Your problem will continue unabated.

Furthermore, if the system is trying to cover two bases, that is oxidation and disinfection, then the chlorine feed may need to be increased, the retention capacity enlarged and a backwashing becomes filter essential.

Did that company offer you a backwashing filter and you decided against it because of cost or some other reason? If so, then they should have insisted at risk of losing the sale.

What often happens is the customer is so fed up with changing filter elements that they just remove it and let the softener act as such. Big mistake! The new owners of the home may not understand those aspects and wind up damaging the system, producing poor water and regreting their purchase decision.

Andy CWS

Sediment filters are designed to remove...sediment. Not iron. Although ferric iron can be removed with sediment filter, ferrous iron will, in large part, pass through the sediment filter. Work with a water treatment professional to specify and purchase a whole house filter designed specifically for iron. Apparently your current contractor is not a good choice.