Hard water

[Neofolis]

I have been using a misting system for the past couple of months to regulate humidity in my polytunnel and it has proven much more successful than the humidifier I was using previously, as well as not using any electricity.  The problem is that living in a hard water area, I am getting quite a lot of calcium deposits on leaves which is rather unsightly (maybe even damaging?).

What is the best remedy?  I remember a short while back a thread about reverse osmosis, but all of the home systems I have found seem to be geared towards drinking water and only feed a silly tap, which wouldn't have sufficient pressure to feed my misting system.  The pressure, I assume can be overcome with a pump, assuming there is sufficient water available.  Are there any other solutions? (I probably should have used the word alternatives), chemical additives, filtration, etc?  I seem to recall people mentioning softeners, but they need to use an alternative softening medium that was not sodium/chlorine based, was it a nitrate of some kind?  I have to say, I prefer the idea of removing things from the water rather than adding things to it.

[jrod]

I'm not sure if this helps but I came across this the other day.  It might be worth checking into.

http://www.advancegreenhouses.com/reverse_...m_from_adva.htm

[Neofolis]

Thanks Jared.  It may be suitable, I don't know if it has sufficient pressure for the misting jets (min. 3 bar), but a pump may be an option.  I doubt I would use as much water as it can produce, so that shouldn't be a problem.

[PALM MOD]

Here is a recent thread on R.O. water.

http://palmtalk.org/cgi-bin....osmosis

[Neofolis]

Thanks Dean, I did refer back to that thread, but it doesn't really help with my situation.  I know reverse osmosis is what I really need to remove sufficient calcium, but I'm not sure how I can set it up for use with my misting system.

I assume I will need to store the purified water in a tank and then pump it from the tank to the misters using a 3 bar single impeller pump or similar.

I have very hard water and my Butia X Jubaea has got thick limescale on the leaves now, it's not just a white powdery coating, it's a thick build up like on a kettle element.

[Phil]

Neofolis,

RO works by making salt free water and then saving it for when you need it.  This is usually in a tank.  Now, if the tank is full and the system is pumping in more RO water into the tank as you use it, your driving pressure is going to be the same pressure exiting the membranes (the RO system).  This is probably enough pressure  to run a sink drinking water faucet, but probably not enough for your needs.   So, for your purposes, I anticipate you'd need a small pump to drive water from the tank to your plant fogging tips.   A possible way to do this is to hook up a humidistat in line with the pump (Honeywell makes one).  The humidistat says "it's dry" and turns on the pump which starts the fogging.  The pump could be a really low flow as foggers take little water.  But, it would be an expense.

Phil

[Neofolis]

Thanks Phil, that's kinds of what I anticipated needing, but I can't find anything that does exactly that, at least not in the UK and I don't know if a US product would be compatable with our power supply.

I think I'll have to go for a standard RO system that is designed to connect to a tap and instead feed it to a tank with a ballvalve, so that it shuts off when full, although I still have the problem of adapting from the silly, little hose provided to the ballvalve.  From the tank onwards it shouldn't be a problem, because I can use a demand activated pump, either with a humidistat, water timer or manual control.

Ideally I would like a water timer that I can set to come on for just a few seconds to avoid wetting then switch of for 1-2 minutes, but most of the timers I have seen seem to be only programmable to be on up to 6 times per day.  Even a humidistat would not be sufficiently responsive and has the other problem that if the temperature got too high, it would be on permanently trying to reach the required humidity level.

[jrod]

I'm not too familiar w/ bars of pressure but 3 BAR is about 43.511 PSI, so that is a fair amount of pressure needed.  Are you able to elevate the tank?  You could create pressure that way but i suspect you will need a pump to drive the system.  It shouldn't be too difficult to setup though.

As for controllers, there are a few controllers that will do what you want.  Here is one I know of.  I know there are more out there but they can be hard to find.

http://www.dripirrigation.com/drip_ir....s_id=87

You could also use a Cycle Timer and 24 Hour Timer like these.

http://grannyshouse.com/page.cfm/61

http://grannyshouse.com/page.cfm/65

I'm not sure if any of this would work w/ your electrical systems but if you could find them, they would do what you needed them to.  If you need help w/ anything else, just let me know.

[edbrown_III]

your pretty much stuck with a pump either way to lift it.

Most misters need atleast 30 psi ( 2.5 Bar)... Could you capture rain water and repump? .  

The other way is you put in a lime or zeolite softener to take out the cations such as calcium etc. ----it adds some chlorides but some plants can take a few of these.

Best regards,

Ed

[Neofolis]

Thanks Jared, that last link does kind of what I want, but I would prefer to have a bit of flexibility rather than a preset on/off time.

To get 3 bars from gravity, I would have to raise the tank 30 feet, which wouldn't be practicle, so a pump would be more sensible.  Rainwater is an option, but doesn't guarantee a constant supply, although I suppose I could supplement the supply with ny normal water.

[jrod]

I didn't think it would be possible to get the pressure you needed from gravity but I wasn't sure how large your property is or if there was possibly a large hill on the property.  A pump sounds a lot easier anyways.

Here is a little more info on the DIG timer(1st link).  It is difficult to see on the information but it should do what you want.  It has 2 misting cycles that offer a lot of flexibility.  http://www.middlecity.com/backyard/mistbed.shtml .  There are also plenty of other models out there offering a lot of flexibility but i'm not sure what your budget is.

[Neofolis]

This is probably a really stupid idea, but I remembered Bill (BS) talking about using the water he gets from his dehumidifier and I was wondering, if it would be possible to run a dehumidifer outside all the time, protected from the elements obviously, collecting moisture from the air.  I don't know how much they cost to run for up to 24 hours per day or how much water they would collect, particularly when humidity levels are low and also whether they can be set to run, without a preset humidity target, i.e. can I set it to zero humidity, so that it is still trying to dehumidify when the surrounding air is less than 20% humidity.

[Neofolis]

Can I assume from the lack of response that it was indeed a stupid idea.  It just seemed that reverse osmosis wouldn't be cheap and I need to do something, because the plants are not liking my water.