Designing Chlorination Setup - Need Help

[Dwassner]

I sold my AIO and am looking to build a chlorination setup. I see kits online that come with all the components for a full setup but am skeptical about if I can buy the individual parts separately and have a better setup for cheaper.

-How do I size the retention tank? I am guessing something like: (X gallons per minute) x (X minutes of contact time), but am not certain.

-I see some tanks can be equipped with pressure and vacuum relief valves. Do you think this feature is worthwhile?

-would you recommend an in-line mixer?

-Aside from ease of plumbing, is there any advantage to tanks with both the inlet/outlet on top of the tank vs those with one on top and one on the bottom?

-how do I size the cu ft bed size for the carbon filter? I am guessing something like: (ppm of h2s + ppm iron + ppm residual chlorine) x (gallons per day) x (days between regen), but am not certain. Is there a standard amount of 'used' and residual chlorine that a cu ft of carbon will hold until maxed out?

Thank you!
Dustin

 

[Bannerman]

A baffled contact tank will be more effective than a plain contact tank.

Raw water and the injected chlorine should enter the tank at the bottom but there will typically be a small internal riser tube so the incoming flow will not stir-up the sediment that will accumulate at the bottom. A full port ball valve will be used to periodically eliminate the accumulated sediment to drain.

A carbon tank should be sized for the flow rate. Usual recommendation is 1-3 GPM per cubic foot of carbon.

Carbon has high capacity per cubic foot so it will typically take years for the carbon to be 'maxed out', but the media capacity is also dependant on which specific contaminants are being removed. Carbon is not regenerated but the backwash cycle will eliminate any sediment and debris that had entered in the Raw water. Backwashing will also reclassify the media to eliminate channelling which will eventually occur when water follows a consistant path through the media.

 

[Sponsor]

 

[Dwassner]

Thanks, Bannerman.

A few other questions:
-how do I size the contact tank?
- how are the tanks (Clack in particular) drained of sediment if both the inlet and outlet are on the top of the tank?
-does an in line mixer need to be used with both baffled and plain tanks?

What I meant by 'maxed out' was thinking more along the lines of a softener. Does the carbon not 'absorb' or filter the residual and 'used' chlorine, and then the backwash flushes this out? I guess I am looking at this like a softener, probably incorrectly...

Thank again.

 

[ditttohead]

Carbon cause the chlorine to revert to Chloride, it does not backwash out the chlorine.

Most of the DIY systems sold online are knock-off cheap imported lowest cost junk. Avoid the majority of the online water treatment companies. Before we can really make any intelligent recommendations, can you post your water report?

Retention tanks with the inlet/outlet on top are designed a little different but basically work the same. Baffled contact tanks are definitely preferred for most applications, the technology/manufacturing requirements to add internal baffles is simply not worth the cost to many companies. Inline static mixers are excellent but they can also foul up very quickly and should be installed in a way that they are easily serviced of replaced/bypassed.

 

[Dwassner]

-iron fluctuates between .5 and 2.0 ppm. We get sludge in our toilet tanks, so I believe this means there is iron bacteria? There has never been rust color in the water...
-h2s I believe is .5ppm last time I used my test kit, which I do find to be difficult to use compared to my hardness and iron kit. The little color strips are difficult to read... We can smell and taste it, and it comes and goes throughout the year.
-hardness is in the low 50's. The softener has been taking care of this and the iron very well for 8+ years.

The AIO I had removed all the iron but could not take care of the h2s even when regenerating every night.

With the inlet/outlet on top, is there a sediment drain on the bottom?

 

[ditttohead]

Yes, but these tanks do not have baffling. With your water quality baffling may not be that important. Chlorine injection should be done base on flow. Do not bother with diaphragm pumps when using chlorine, the checks require too much maintenance. A chlorine injection system and a catalytic carbon backwashing system may be adequate. A simple static mixer may also help.

 

[Dwassner]

Thank you, Ditto.

How do I size the contact tank?

What kind of pump do you recommend?

Dustin

 

[ditttohead]

A high end peristaltic pump tends to be the most reliable and simplest to maintain. As to the contact tank, I have a calculator I use but in general bigger is better. I will send you a PM.