Odd Fleck 7000SXT configuration possible?

**zver11** · 01-07-2013, 05:36 AM

I have a Filox iron filter with a Fleck 7000SXT followed by a 200 gallon tank radon aerator with its own repressurization pump. Aerator follows iron filter (and backwashable sediment filter) to avoid fouling. However, during Iron filter backwash, it would be nice to have the aerator tank's additional flow of oxygenated water through the iron filter.

Top of the Fleck control has a large 1" connector over inlet side which is used for exiting backwash water. With an attached 1" drain line, backwash flow drops pressure to zero so there is no new flow to aerator tank during backwash. I notice on the output side of the 7000SXT control head , there is a cover for what looks like another access port on top of the filter. Would attaching a line from the aerator output to this port cause aerator water to enter the filter during backwash? If not, is there another port that could be used? I, obviously, do not want constant flow in this route but want flow from this independently pressurized line to enter the filter to supplement during backwash.

**Gary Slusser** · 01-07-2013, 06:45 AM

How do you control the well pump and is the control after or before these filters?

**zver11** · 01-07-2013, 11:04 AM

Detail of configuration:
Part I: Well pump to pressure switch/pressure tank then iron filter then sediment filter output into aerator tank.
Part II: Aerator is sprayer type which fills its own 200 gallon tank. 1/2hp submersible pump in aerator tank controlled by second pressure switch feeds aerator's pressure tank which then outputs house water supply.

The house is fed by the aerator even if the well pump were off. There is therefore no current loss of water pressure when the iron filter is backwashing as long as water draw not exceed aerator tank reserve. When the aerator tank drops below a certain level, an automatic valve opens accepting input from Part I system.

**Gary Slusser** · 01-08-2013, 05:21 AM

If the backwash causes 0 pressure from the well, then something is wrong with the pipe from the well to the filter, like a water leak, worn out or undersized pump (gpm and/or hp) or a too large or missing DLFC in the filter control valve. Or both filters are backwashing at the same time. I suspect you might have a jet pump feeding the filters, no?

The answer to your question is no, you can't add water from after the filters.

**zver11** · 01-08-2013, 09:28 AM

Water pressure drops to near zero because very little resistance to flow--large diameter of all flow channels in Fleck 7000 series, 1" PVC feed, 1" ID backwash output line means little resistance to flow. A little surprised Filox does not provide more resistance, but there is strong water flow out backwash line during backwash. Both pumps are submersible.

Water I want to add is from storage tank of aerator--there is no question that adding it helps boost backwash flow. I can do this manually with current ball valve configuration(configuration serves as a large manual bypass everything option--but opening correct sequence will feedback to input). I would just like to do it automated. When used in certain configurations, control heads allow feeds to enter the backwash stream (e.g. brine for water conditioner, potassium permanganate solution for greensand chlorine injection for iron filters etc.). These are typically low flow unpressurized streams. I would like to add a pressurized water stream instead. The source exists and works. It is just a question of if there is a simple input that will connect this source of water during backwash but cut it off when valve is in service position.

**Gary Slusser** · 01-09-2013, 05:28 AM

My 25 years of sales, installations and servicing thousands of filters etc. says: If the backwash causes 0 pressure from the well, then something is wrong with the pipe from the well to the filter, like a water leak, worn out or undersized pump (gpm and/or hp) or a too large or missing DLFC in the filter control valve. Or both filters are backwashing at the same time.

Plus now I'll mention the possibility that the backwash water isn't going through the mineral due to a broken distributor tube or no o-ring on the distributor tube. That would allow most/all of the water flow out the drain line instead of up through the mineral but.. the DLFC button should limit some of the total gpm output of the pump and that would prevent the pressure from falling to 0 psi.

Also, the capative air in the well pressure tank may be low and/or... the pressure switch is set wrong. The air in the pressure tank, with no water in the tank, should be 29 psi for pressure switch settings of 30/50 or, 39 for 40/60, with no water in the tank.

That plate you mention on the top of the control valve is where an injector would be to introduce a regenerate for a mineral that can be regenerated with potassium permanganate or bleach etc.. So you can not add aerator water to the valve anywhere other than the water inlet to the valve (as you already are), and millions of other filters over the last 60-70 years haven't needed that additional water flow so lucky you, since you believe there's nothing wrong with your filter, you got yerself a "special" one.

**Tom Sawyer** · 01-09-2013, 12:08 PM

Just for grins, change the pressure gauge

**zver11** · 01-09-2013, 01:26 PM

Sorry if I sound as if I am arguing with you. My writing style leaves room for improvement. I am asking because you are the expert. I learn from your comments and do appreciate them.

The loss of water pressure during backwash was not a concern to me since it did not affect service since at 3:30am, the aerator tank provides adequate water supply to the house even with the well flow interrupted.

What I have observed:
1) main pressure tank holds pressure, pressure switch works (based on behavior, pressure gauge, and a good tire pressure gauge measuring air pressure in the empty pressure tank.

2) Well pump can move water at just under 8 gpm(at pressure tank based on tank fill volume/tank fill time test), no symptoms evident during normal use. Well pump is relatively weak for a deep well, but I suspect this was intentional since well production capacity was low during initial well installation testing. Pump uses a three wire system with above ground controls. It is likely that, on sustained flows, well output gpm could drop as the water level in the well drops. Initial well installation testing showed 400 foot drop in water level during the 30 minute test pump.

3) zero pressure only on backwashing folox filter. Other filter has 1/2" backwash line and backwashes normal. There is significant water flow through the filox filter control head during backwash(I can not measure it easily but see and hear it flow). The "DLFC" is a straight 1" tube--maximum flowrate as provided by the seller of the filter. Since I have done manual backwash to observe, I know nothing else is running during this single filter's backwash.

4) When doing a manual backwash and supplementing it with aerator pump flow (expect combined flow easily 20gpm), I can hear a sound I suspect is the filox media lifting in the tank at the start of flow(sound like sand or gravel moving).

I believe well output is low. I interpreted this as the likely source of pressure collapsing during backwash. Filox filters are great at iron/manganese/sulphur removal but have the difficult requirement that ideal backwash flow is double service flow. I used a 1" inner diameter backwash line and 1" PVC plumbing to the filox filter i order to maximize this flowrate. A narrower diameter line or restrictive DLFC would have slowed flow and might have allowed pressure to remain for the bypass. The problem of achieving adequate backwash flow is common for all variations of high purity Manganese oxide filters. One solution I have heard is to put two small filters in parallel with different backwash times. I was hoping for an alternative solution given that I have an (admittedly limited) alternative source of backwash water in the aerator tank.

**Gary Slusser** · 01-09-2013, 02:07 PM

It sounds as if someone possibly removed the DLFC button in the control valve. It goes in where the drain line connects to the valve. It has nothing to do with the ID of the drain line.

Without a DLFC button you get all the water out the drain line that flow through the mineral will allow. That runs the risk of dumping mineral out the drain line.

I don't know much about Filox but I do know a lot about greensand and Pyrolox and with a good flow control valve, you always use a DLFC button based on the cuft size of the filter Or you use an external flow control if the valve's choice of buttons don't go up high enough.

The other possibility is the water level in the well falling so far and a pump that was fine for the system before adding this filter but isn't know.

**Bob999** · 01-09-2013, 05:43 PM

Poster said his well pump only produces 8 gallons per minute. That isn't much for a filox filter except for the smallest size. With a larger media tank a 10, 12, or more gpm DLFC would be indicated and if the supply is only 8 gpm then the pressure is going to be very low--approaching zero.

**ditttohead** · 01-09-2013, 08:43 PM

Filox should be backwashed at 20+ gpm per sq. ft. of bed area, and the fact that he has a 1" drain connector indicates his DLFC button will be no smaller than 8 GPM. Assuming a 10" diameter tank, he probably has a 10-15 GPM button, obviously exceeding the pumps ability. BTW, backwash rates are not based on cu. ft. of media, backwash rates are based on Sq. Ft. of bed area, media type, water temperature, and manufacturers recommended bed expansion during backwash.

**Gary Slusser** · 01-10-2013, 05:10 AM

Originally Posted by Bob999

Poster said his well pump only produces 8 gallons per minute. That isn't much for a filox filter except for the smallest size. With a larger media tank a 10, 12, or more gpm DLFC would be indicated and if the supply is only 8 gpm then the pressure is going to be very low--approaching zero.

Yeah that's what he said he measured but I doubt he has an 8 gpm pump. And we don't know how deep the water level was in the well when he got the 8 gpm.

**Gary Slusser** · 01-10-2013, 05:37 AM

Originally Posted by ditttohead

Filox should be backwashed at 20+ gpm per sq. ft. of bed area, and the fact that he has a 1" drain connector indicates his DLFC button will be no smaller than 8 GPM. Assuming a 10" diameter tank, he probably has a 10-15 GPM button, obviously exceeding the pumps ability. BTW, backwash rates are not based on cu. ft. of media, backwash rates are based on Sq. Ft. of bed area, media type, water temperature, and manufacturers recommended bed expansion during backwash.

You are assuming he designed this filter instead of buying it from a dealer, or if he is a dealer, from a supplier that included the correct size DLFC for the type of mineral and cuft size filter he bought. Plus we don't know the cuft size yet.