09-11-2006, 08:14 AM
Just for a bit of clarity, pun intended, the UV treatment of water is not a filter. It's a high-intensity UV bulb (like a fluorescent tube) that kills lots of, but not all, pathogens. It's usually used in conjunction with a series of filters. The bulbs can last a year or more, your mileage may vary (YMMV), but you do need to check it periodically to see if it's functional.
The series of filters will take out particulates to pathogens. These may need to be replaced as often as every month or less, YMMV. You can choose different pore sizes of filters: 30 microns down to 1 micron. A 1 micron filter may take care of the tiniest pathogens, but you sacrifice water pressure.
You can counter the lower pressure with a larger pressure pump, which means more dollars and probably an associated electrical bill increase. You may be looking at going from something like a 1/2 HP pump to a 1 HP pump, depending on your situation, to get your water pressure up to an acceptable level.
The last of your filters might be a carbon filter, which is supposed to clear up the taste, such as iron and chlorine. You can go with activated charcoal or carbon block, the latter also reduces water pressure, I believe.
In California, we had an ozonation system that treated our well-water in our storage tank. This cleaned up the water by exposing it to a UV bulb that created unstable ozone molecules (O-superscript3). The ozonated water would be cycled back into the holding tank using a diffuser that oxygenated the tank water. In the tank, the ozone molecules would recombine as oxygen molecules (O-superscript2) and, as in a mountain stream, would kill pathogens with the exposure to the oxygen molecules. This is similar to treating your water with hydrogen peroxide (HO), I think, where these unstable molecules recombine as water and oxygen molecules. Unfortunately, HO is expensive.
One would think that ozonation would be like UV treatment, but I think there's a difference in the intensity of the light. I think the UV tube in an ozone system is smaller than in a UV system (both tubes are still pricey). I don't know if a UV system uses ozonation as part of its method, or if it's just killing pathogens by exposure to that wavelength of light. Perhaps there's a list member who knows about the specifics of these systems.
I've been told that ozonation doesn't work on typical catchment systems because tank water levels are rarely constant and may be cloudier, which reduces the effectiveness of ozonation. In our well holding tank in CA (a 5K gal. plastic one, BTW), the water level was kept constant by way of a limit switch triggered by a float. When the water level dropped, the float dropped with it, turning on the well pump. When the float rose to a preset level, it would turn off the well pump. Ozonation had an added effect of precipitating out a lot of the minerals (like iron oxide, aka rust) in the water which was confined to a large, cylindrical paper filter.
I've been told that well water is considered "tastier", in general, because it usually has more mineral content. Catchment water on the Big Island is said to lack the mineral component, aside from some sulphuric acid from the volcanic activity. Does anyone feel that this is the case? Has anyone "improved" the taste of their catchment water by adding minerals? If so, what have you done?
If you drill your own well, it's probably imperative to have a treatment system of some level, given the number of cesspools in use around and upslope from your location.
Caveat: I'm not a water treatment expert, I'm just another catchment user.
Les
Edited by - Les C on 09/11/2006 12:19:57
The series of filters will take out particulates to pathogens. These may need to be replaced as often as every month or less, YMMV. You can choose different pore sizes of filters: 30 microns down to 1 micron. A 1 micron filter may take care of the tiniest pathogens, but you sacrifice water pressure.
You can counter the lower pressure with a larger pressure pump, which means more dollars and probably an associated electrical bill increase. You may be looking at going from something like a 1/2 HP pump to a 1 HP pump, depending on your situation, to get your water pressure up to an acceptable level.
The last of your filters might be a carbon filter, which is supposed to clear up the taste, such as iron and chlorine. You can go with activated charcoal or carbon block, the latter also reduces water pressure, I believe.
In California, we had an ozonation system that treated our well-water in our storage tank. This cleaned up the water by exposing it to a UV bulb that created unstable ozone molecules (O-superscript3). The ozonated water would be cycled back into the holding tank using a diffuser that oxygenated the tank water. In the tank, the ozone molecules would recombine as oxygen molecules (O-superscript2) and, as in a mountain stream, would kill pathogens with the exposure to the oxygen molecules. This is similar to treating your water with hydrogen peroxide (HO), I think, where these unstable molecules recombine as water and oxygen molecules. Unfortunately, HO is expensive.
One would think that ozonation would be like UV treatment, but I think there's a difference in the intensity of the light. I think the UV tube in an ozone system is smaller than in a UV system (both tubes are still pricey). I don't know if a UV system uses ozonation as part of its method, or if it's just killing pathogens by exposure to that wavelength of light. Perhaps there's a list member who knows about the specifics of these systems.
I've been told that ozonation doesn't work on typical catchment systems because tank water levels are rarely constant and may be cloudier, which reduces the effectiveness of ozonation. In our well holding tank in CA (a 5K gal. plastic one, BTW), the water level was kept constant by way of a limit switch triggered by a float. When the water level dropped, the float dropped with it, turning on the well pump. When the float rose to a preset level, it would turn off the well pump. Ozonation had an added effect of precipitating out a lot of the minerals (like iron oxide, aka rust) in the water which was confined to a large, cylindrical paper filter.
I've been told that well water is considered "tastier", in general, because it usually has more mineral content. Catchment water on the Big Island is said to lack the mineral component, aside from some sulphuric acid from the volcanic activity. Does anyone feel that this is the case? Has anyone "improved" the taste of their catchment water by adding minerals? If so, what have you done?
If you drill your own well, it's probably imperative to have a treatment system of some level, given the number of cesspools in use around and upslope from your location.
Caveat: I'm not a water treatment expert, I'm just another catchment user.
Les
Edited by - Les C on 09/11/2006 12:19:57