Water Catchment Systems

[rmelzig]

Need recommendations for catchment system expert(s).

Recent arrival. I replaced filter cartridge holders and am changing filters (10, then 5 micron) monthly. Also re-furbed UV system (kept only beautiful ($$) stainless steel cylinder; replaced quartz cylinder, lamp and ballast). Pump is the on-demand style with no bladder tank.

Anyway, the system has developed a vibration that fills the piped portion of the house with its noise whenever the pump starts. Also, pump start seems to take longer from first water flow each time.

Also would like expert to opine on general condition of the system. I have no experience with catchment, but some with wells. [Frozen pipe between well and house presents interesting problem. Have good "how did he do that?" question for high school physics students].

Rick Melzig

[hotinhawaii]

Sometimes an on-demand pump will cycle on and off very quickly and repeatedly when it starts up. (Not enough pressure, too much pressure, not enough pressure.....) Don't know an expert to refer you to though.

Why are you changing the filters every month? What size cartridges are they 10" or 20", narrow or wide? You can probably go for at least 3 months and more likely 6 months before you have to change them depending on your usage and how dirty your catchment water is.

[KeaauRich]

Try calling Stefan Larsson at Big Island Catchment (756-3033)or Hope at American Water Purification (935-3930)

[Jay Bondesen]

I haven't heard of knocking here. On a well in California I had a similar problem and had to add an air chamber to relieve 'water hammer' where when a faucet would be shut off suddenly the pipes would shudder. Did you change the piping? You need at least a foot or two of straight pipe on the pump outlet or the backpressure from an elbow might make it think pressure was up and it would turn off and then right back on. Also, I use a bit of bleach in my tank occasionally and where you have the 5 micron mine would also be carbon to take the chlorine back out as well as some other things.

Jay

[hrooster]

We had the same problem: air hammer effect. Solved with a (I think...)30 gallon pressure tank. No more knocking!

http://the-hroost.com

[rmelzig]

Thanks to all for the quick responses.

The filters are about the size of a standard paint roller, so I guess 10". I have been buying the carbon version of the 5 micron. I not sure of a simple way to put chlorine in the tank - short of unlacing the cover and schlepping a ladder down there.

I think that the frequency of the vibration is way higher than what I remember to be a water hammer. Ditto the pump cycling on/off very fast. Lacking access to an audio spectrum analyzer these days, I'm going to guess that the frequency of the vibration is about 100 Hz. Folks at the Water Works downtown told me the the Grundfos MQ pump is not intended to be used with a tank.

Going to make a couple of calls; will post resolution.

Rick Melzig

[Jay Bondesen]

I'v seen the MQ used successfully but they do have a capacitor start that can go out, actually overheat and pop open. It isn't the best but can work fine for a long time. As for adding bleach, I lift up the edge of the cover, toss in about three gallons of water mixed with a cup or two of bleach, and then stir with a kayak paddle. The 10" filters are fine, 20 micron first from the tank for the large stuff and then 5 micron carbon to get it cleaner before the UV tretment. They won't get it all though and some also have a 1 micron filter just for drinking water. The changing schedule depends on how much water you use and how much 'stuff' lands on your roof and gets to the tank.
Check out the pamphlet Rainwater Catchment Systems for Hawaii by Patricia Macomber done for the CTAHR at the University of Hawaii. She lives here in Puna. No agency will take the responsibility of really telling you what to do but she has a lot of good information so you can make your own choice. It's easy enough but you do have to maintain the system. We have been using catchment for all of our household water and so far so good. (four years now)

Jay

[rmelzig]

Thanks to everyone! Hope at American Water Purification had the answer.

She said check the alignment of the filter cartridges with the top lid of the cartridge holder. Couldn't see it by visual inspection of the alignment of the first (10 micron) filter in its holder, but close inspection of the plastic insert at the top of the "spool of string" showed the insert pushed just slightly out of position; it was off (1/16" +/-). Turn of the month = new filter time, anyway. Perfect.

Rick Melzig

[birdmove]

Also, if you notice a water pressure problem, it's time to replace both filters.You'll notice, for instance, if you flush the toilet, the sink faucet will run slower.That's what happened to my place.R&R both filters, and got normal pressure. I haven't yet figured out how often to change filters time-wise.

jon

Jon in Puyallup, Wa.

[KeaauRich]

Hope rocks! Glad she was able to solve your problem. As to when to change the filters, we do it whenever my shower won't wash the shampoo out of my hair. It's as accurate a gauge as any other