2009 November | CAI Water Softener Systems | Filters

PH Neutralizer Clogged

I have a PH Neutralizer that I bought from you some years ago. Periodically I have been adding more media, most of the time when the level drops about 1/3 of the way down the tank. I started off with pure calcite, and over time have moved to a 3:1 mix of calcite and Corosex, and the PH is still in the 6.0 range. Today, suddenly, our water pressure went down, dramatically. I guess it’s been coming on over a period of time, because when I bypass the tank the pressure is a lot higher than it was recently. Running a couple of extra regeneration cycles hasn’t helped. What should I do? Do I have to disassemble the whole tank and start with new media and gravel, or can this be rescued? The tank is about 3/4 full…Thanks.

Answer: There are a few issues here to discuss that relate to correcting pH with a backwashing neutralizer.

1) Total Dissolved solids – A good neutral pH range is between 7 and 7.8, and your pH should be corrected to protect your piping and fixtures from acid attack (may be visible as green staining). You have two ways to proceed here, and the best way depends on your level of “total dissolved solids” (TDS). With a relatively low TDS the most common way to correct pH is with a calcite based automatic backwashing neutralizer. If your TDS is very high, a standard calcite based pH neutralizer may not function very well. This is because the way in which a calcite neutralizer works is that the media (calcium carbonate) slowly dissolves into your water over time. With a high amount of material already dissolved into your water, the neutralization process will not work effectively using this technology. It is possible that your level of TDS is very high, and the contact time within the tank is not sufficient to correct pH to within a normal range. If this is the case, you may need to consider a chemical injection system, as this chemical injection functions well regardless of the level of TDS. When you purchased the equipment, did we measure the level of TDS? If we did, and still recommended a calcite filter, this is not likely the issue here.

2) However, another issue comes into play here – very low pH. There is a practical limit to how large of a backwashing neutralizer can be installed into a residential application. As discussed above, the calcite in the neutralizer dissolves into the water to correct pH. This requires sufficient time for the water to be in contact with the calcite for this process to function correctly. At a very low pH level, a large neutralizer is required to correct pH regardless of the TDS level, as the water requires a substantial contact time within the bed. One concern here is that many residential well pumps do not have the ability to provide the required flow rate needed to backwash larger neutralizers (2 ft3 and larger). Not backwashing a neutralizer properly leads to channeling within the bed, and poor performance over time. A smaller backwashing neutralizer (1.5 ft3) may be sized correctly for a typical residential application, but possibly not large enough to correct a very low water pH. Again, if this is the case – we might recommend a chemical injection system – however, this depends on your initial water analysis.

3) Another consideration is the media mix ratio. Corosex (magnesium oxide) is a more powerful neutralizing agent, and can be mixed with Calcite (calcium carbonate) to improve the pH correction process. The issue here is that Corosex is much “softer” and can tend to agglomerate, and form a solid body within the neutralizer if not backwashed effectively. When increasing the mix ratio to combat a very low pH you must be sure that you have sufficient backwash flow available. For instance, a 10 diameter tank (used in a 1.5 ft3 neutralizer) requires 7 to 8 GPM backwash. A larger 12 inch diameter tank (used in a 2 ft3 neutralizer) requires 11 to 12 GPM. If you do not have this flow available, you may develop problems over time that requires replacement of the media. This is probably the reason you have noted a pressure drop issue lately. You will need to re-bed the unit with new calcite and gravel. Replacement media is available on our site on the “Chemicals, Resin & Filter Media” page. We also recommend that all backwashing neutralizers are completely emptied and replenished every five years to provide good function over the long term.

4) The last consideration is to refer back to your initial water analysis. Did we ever perform one? If so, was you pH corrected for any period of time after installation of the equipment as recommended? To further trouble shoot your problem, it may be better to speak with you directly, just give our technical service people a call or send them an email at you convenience.

Nuisance bacteria

Since we moved into our house 2 months ago, we have been trying to find a solution to the nuisance bacteria we seem to have, which is resulting in a strong, sulfer-ish smell in the kitchen, bathroom, and laundry room. We have already replaced the sacrificial anode in the hot water heater with a zinc anode rod, then we removed the rod altogether. Each time, the smell has left, but only temporarily. My question is this: would an iron filter remove the iron that is leading to the baceria build-up, thereby removing the smell? If so, is there a brand or type that you would recommend? Thank you!

Answer: If your problem is due to the presence of a nuisance bacteria (like iron or sulfur bacteria), then chlorine injection is the best solution. The chlorine first kills the bacteria present on the outside of the iron or sulfur particle, and then with the bacteria destroyed, the chlorine oxidizes the iron or sulfur into a precipitate. If you decide to go this route, your should also install an automatic backwashing carbon filter downstream of the chlorine injection system. The carbon filter will remove the injected chlorine from your water, and also filter out any precipitate formed during the chlorine oxidation process. To see if this is the cause of your problem, just remove the lid from any toilet tank, and check for the presence of a slimy growth on the sides of the tank. Sometimes you may also see an oil like sheen on the top of the water.
If the tank seems to be free of this material, (sometimes just a black stain may be present), your problem may instead be due to the presence of hydrogen sulfide (H2S) in the water.

In this case, you can consider removing this odor with a system like our Iron-Pro. This is a non-chemical automatic filter that incorporates oxidation by air and a polishing carbon bed to remove the sulfur from your water. You should not use this system if sulfur forming bacteria is present, as the carbon bed in this filter will lose its effectiveness over time due to fouling from the sticky bacteria.

A liquid chlorine injection system meters chlorine directly into your water supply. This system is composed of a chemical feed pump, static mixer, solution storage tank and retention tank. When your well pump comes on, the chemical feed pump adds chlorine solution into the static mixer (which aids in the uniform mixing process) and enters the retention tank where the disinfection/oxidation process occurs. You typically use a starting mix of 1/2 gallon household chlorine bleach to the 15 gallon chemical solution tank, and 4 oz. per gallon of soda ash to start. You then vary the pump feed rate until you obtain the desired residual chlorine concentration (about 0.5 ppm free chlorine) – typically a setting of 50% works well. You can obtain a chlorine test kit locally from most plumbing supply stores (and many pool supplies) – they are very inexpensive.

After the chlorine injection system, you should install a backwashing carbon filter. Consider our model CF15-M, a 1.5 ft3 automatic backwashing carbon filter (Autotrol 263/440i valve and control). This filter has a 20 micron filtration efficiency, and should be installed after your pressure tank to remove the injected chlorine, and also polish any residual hydrogen sulfide (H2S – sulfur).

The other system we discussed for removing hydrogen sulfide, called the Sulfur Pro (also called the Sulfur Breaker), uses a specially designed control valve with a filter tank partially filled with Centaur carbon media. The unit keeps 1/2 of the tank filled with air at all times, and the iron & sulfur in your water is oxidized by the air, and also in the carbon media. It cleans and flushes the bed very aggressively, as air is also contained in the backwash water. The system removes very high levels of sulfur and iron.

You can visit our site to find additional information on both of these systems.

PH Neutralizer Clogged

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