Valves for twin tank (parallel) filter installations?

[EIR]

I see a lot of valves marketed for twin tank alternating water softeners.

The question is, do these valves or any valve allow two media tanks to operate in parallel but backwash independently? (I realize during backwashing that both tanks would be unavailable ).

If not do you think I'd be better off with two single tanks in parallel with their own controllers.

Speaking specifically about GAC applications.

I know ditto has answered this for me in private. I can't find any of shorter squatter tanks (12x35, 12x43 or 16x33) available for purchase.

Pentair has a large list of polyglass tanks they make. I don't see a dealer that offers the uncommon sizes or a place online to purchase.

With my space constraints and with the recommendations of various carbon manufacturers I feel I need to go the parallel tank route to achieve a workable service flow.

 

[Bannerman]

I recall Ditttohead had stated why he recommended a single tank and provided a recommendation as to the larger diameter but shorter Enpress tank he felt would satisfy your requirements. If a dealer does not have that specific tank in-stock, they should be able to order it for you from the distributor or manufacturer, assuming the dealer sell that brand.
http://www.enpress.com/site/products/composite-pressure-vessels/

What is it you want the GAC media to remove? If your concern is mostly chlorine, that is easily removed even when exceeding the recommended flow rate for GAC media. The GAC maybe assisted with a KDF Media Guard if necessary.

If your concerns are related to other water contaminants, perhaps Catalytic carbon would be a more effective media.

 

[Sponsor]

 

[ditttohead]

two smaller tank are usually used for applications where there is inadequate backwash to handle a single tank or to keep cost down vs. a single expensive larger tank. You can also use multiple tanks with "No Hard Water Bypass" options in application where untreated water is unacceptable to the POU.

A twin alternating valve is fine with backwashing media and is actually very common but usually not needed.

I sent you a PM, you are going on many different ideas and I think you are reading way too much information from online. Much of the writings online are simply cut/pasted from someone elses writings that were done too many years ago.

 

[EIR]

I've emailed around. I had several vendors tell me several days ago they would get me a quote the next day. I haven't heard from anyone and need to move on with this.

I am fairly certain I want kdf in front of my carbon to knock down the chlorine and possible heavy metals(we do have some on our report. If it provides any anti bacterial effect even better) . I'd like the gac to pick up what's left. I'll probably just implement a cartridge polyphosphate filter in front of the water heater for the time being.

Not that there's a whole lot to start with. My municipal water is OK most of the time. They have been having issues recently since new management has taken over last year or so. Cloudiness, periods of brown water, etc. I was told by a reliable source they have been having issues with keeping the pH consistent. To me inconsistent pH means an alkalinity issue as well (typically have pH swings in aquariums with an alkalinity issue....I assume it translates to municipal water as well ).

I have been told they have also been sitting idle years before I purchased my home with infustructure upkeep and upgrades. While other towns have fixed up or updated their distribution systems ours has been been simply doing bandaids when necessary.

They have their own wells and also purchase water from other towns.

All of this in addition to our renovation has me wanting to implement a system.

I don't want to finish replumbing the house only to cut a bunch out later to do this. I'd like to plumb it once and walk away.

I feel at the least kdf and carbon for bathing and clothes washing and extending the life of the appliances (ID like to protect the plastic in wall tank of the gerberit toilet carrier from chlorine myself) and a Pou reverse osmosis for cooking and the fridge.

You are right I probably am over reading. I also know I want to use the carbon for more than chlorine removal if I go with a kdf tank ahead of it. Im simply going off of manufacturers specs. Maybe they are a little conservative?

I'm a commercial electrician by trade. I tend to follow the NEC and the manufacturer's recommendations when installing electrical systems. They publish specs and do the engineering, testing and get their equipment through the approval processes. I know it's safe and right if I follow the manufacturers specs.

If the manufacturer States the service flow for their carbon is 1-2gpm per sqft...and the salesman is trying to push a 8" .75cuft tank whose sqft is half and they are telling me it's going to do 6-8gpm fine... I tend to start thinking I need to do this on my own.

I'd like to buy pre assembled and pre filled units from a professional, sized conservatively, in sizes that are going to work for me. I don't need an installer. I'm a tradesman. I don't run water pipe for a living but we run pvc,emt, rigid (essentially galvanized black iron) and build and hang unistrut assemblies.

I can do the installing myself. Ill pipe the electric to them too just for giggles.

I see the manufacturers make several size mineral tanks. Point me in the direction of an online dealer or a dealer in the Philadelphia/South Jersey area who can sell me these and I'm golden like pony boy.

 

[Bannerman]

Some online dealers sell equipment packages where all of the components are supplied separately so you as the installer are responsible to install the riser tube & bottom screen, gravel underbed, carbon media, control head etc yourself. There would be little difference in you obtaining each of the components yourself except you can then choose quality components instead of some bargain components often supplied with packages sold online.

A KDF Media Guard is an insert which fits within the carbon tank opening below the control valve. Incoming water flows through the KDF media before reaching the carbon. Although the KDF volume is less than a separate tank, the M-G is usually adequate for residential use and the service life would probably be similar to the life of the carbon so both medias could be replaced at the same time. Only one control valve would be needed but the backwash rate and frequency would be governed by the media guard requirement.

The stated service flow rate for GAC is the optimal rate for reducing a broad range of contaminants. GAC will adsorb chlorine at a rapid rate so the optimal flow rate maybe exceeded greatly, yet chlorine will still be effectively removed/reduced. As Catalytic carbon utilizes catalytic action in addition to adsorbtion, it can reduce a range of contaminants more effectively than GAC. Inclusion of KDF media in a media guard or prior separate tank would reduce some of the workload on either media.

The Enpress web link was specified previously. Perhaps you are able to buy the appropriate tank directly or they maybe able to specify their dealers in your area.

 

[EIR]

Does kdf and carbon require different riser tubes/diffusion baskets. I'm not sure what they are called in the industry.

I see recommendations for bed depths in the media manufacturers PDF documents. Does the width of the tank affect the media bed depth requirement? (I see the spec as "bed depth 6" tank").

Freeboard is the amount of free space left in the mineral tank after filling with media, correct? For example, say media x requires 50% freeboard. Does that mean 50% of the tank height or 50% of the actual depth of media used. If I used 30" of media I'd need to leave 15" of space? Or if I use a 40in tall tank I need to leave 20"?

What's the typical gravel bed thickness or is there an alternative to gravel? I feel like shorter tanks would need to maximize space inside.

Do you have to buy the "special water filter gravel" or is there just a overall size and grading I can get at a local supplier of aggragates for construction?


I've also seen mentions of a grate for either public water or short tanks or both at the top of the tank. I assume this is for backwash and preventing media from being lost?

Clack only sells to dealers correct? Most of the dealer's I've emailed with use fleck or autotrol. I don't know much about any of them besides the mention that fleck requires specialized dealer tools for servicing and the autotrol valve is dependable in high silt areas but dated.

Finally, do the media baskets actually work for kdf in carbon or are they a gimmick? My gut says stand alone tanks has to be better than combining media, especially with a media like kdf. I can't picture how the water flow through them as effectively.

 

[Bannerman]

A KDF media guard would be slid over the standard riser so the riser remains located in the center of the tank. The standard bottom distributor would be utilized but the upper basket/distributor/screen would be replaced by the media guard which will prevent loss of carbon media.

See Dittohead's comments here: https://terrylove.com/forums/index.php?threads/media-guard-kdf-55-good-or-bad.48908/

There are some performance issues regarding the shorter bed depth but Ditttohead and others have experience and can comment on this.

Freeboard is required to provide space for the media to expand and circulate (re-classify) during backwash. This is typically 50% of the media depth but Dittohead has tested backwash performance for various media and may provide alternate recommendations.

Underbed gravel should be NSF certified to ensure there are no harmful characteristics such as arsenic which maybe within some construction grade gravel.

Enpress offer their Vortec distributor as an alternative to gravel: http://www.enpress.com/site/products/vortech-and-mid-vortech/
There had been some issues with the Vortec system early on but those issues may have been since corrected.

I expect by grate you are meaning upper basket/distributor/screen which was addressed in point #1

Clack valves are not sold to the public DIY market. Some Fleck models remain available to DIY but they too are starting to abandon that market with their new valve models. Most Fleck models do not require specialized tools to service them.

Effectiveness of media guard is addressed in the link provided.

(edited to add information link): http://www.qualitywatertreatment.com/media_guard_filters.htm

 

[ditttohead]

The media guard can be an effective treatment method but it has definite limitations that most companies don't understand.

FYI, freeboard is measured by the media depth based on tank size, but the tank measurement is only considered as the sidewalls, the domes are not calculated into bed depth or freeboard calculations. On steel tanks this is easy as we measure weld to weld. On fiberglass tanks, some manufacturers have taller tank domes than others.

The Fleck valves can usually be rebuilt without special tools but the tools make it much easier on some valves. ie: the 2510, 2850, 2750, 2900. The 5600, 9000/9100, 7000 are easily rebuilt without the special tools but they are available. All new Fleck valves use a cartridge similar to the Clack valves but if memory serves me correctly, Fleck developed the cartridge technology in the 70's, they just never made it standard until the past few years.

Do not mix KDF and carbon in the same tank. KDF requires 3x the backwash of GAC and thus simply falls to the bottom of the tank and turns into a clump. Many companies still do this but the actual purpose os more for marketing rather than function. If you want the KDF to truly be effective it needs to be separated into a different tank or in the media guard, assuming you understand the limitations of the media guard. The link states no maintenance is necessary... it does need regular replacement. It also requires a very specific backwash rate to work properly and not foul up.

 

[Reach4]

With a Mediaguard, I assume that all water that passes through the dip tube will pass through the Mediaguard. I had been suspecting that the dip tube would be shortened to use with Media guard. However I now suspect the Mediaguard instead replaces the Distributor Pilot Sleeve -- the bushing that goes between the main valve body and the dip tube. Is that the case?

 

[ditttohead]

No. The water passes through a complex unit (media guard) that separates the water through 4 individual cambers as it enters the media tank. Each module contains approx. 1 lb of KDF. If you notice on the diagram, the media guard goes into the media bed but the exit is above the media as one of the exit channels is halfway up the media guard. The other exit is halfway between the middle and the top of the tank.

The riser tube is a standard 1.05" design that goes all the way into the valve. The media guard slips all the way down the riser and is attached to the valve and is o-ring sealed to both the riser at the bottom and the valve. Since the media guard only has 4 pounds of KDF, regular replacemtn is recommended. Annual to every 3 years is typical.