Hey Jon, you can check your pressure with a simple PSI gauge, that I think you can hook on the end of a garden hose. Something like this…
http://www.plumbersurplus.com/Prod/Winters-EWT213-Economy-2-Water-Test-Gauge-0-160-PSI/12479/Cat/887
Or you can buy the super duper bells and whistles RODI unit with TDS meters, PSI guages and booster pump and pressurized drinking water storage tank and permeate pump all built in.
One thing to remember. I just noticed my RO water production took a nose dive because the tap water temp is dropping. the ground is cooler with the feed pipe, and the attic where the copper house piping runs is cooler now, rather than 120 degrees like in summer. So the membrane passes less water.
But the booster pump will fix that.
I finally got around to getting a pressure gauge from Lowes and found my PSI to be around 42psi. Not as high as I had hoped. I hope the reading was accurate. The gauges gasket stunk and there was a slow drip.
Because of current budget restrictions I am going to skip the second RO membrane which would require a booster pump with this low of a psi.
Has anyone ever seen any info on how much extra PSI is needed for each additional DI cartridge of prefilter. Still trying to decide on a unit and would like to get the most complete system I can with the psi I have found in my basement.
[glow=red,2,300] >::: EERRRRrrrrr >:::[/glow]
It has been such a royal pain in the _ getting straight answers from the companies that make RO units. One of them tells me my pressure is crap and I have to buy a booster pump or my unit is going to be VERY inefficient and dump tons of water down the drain. They also make it seem like it would be impossible for me to get anything out of a water saving second membrane. The other company says all I need to run a 75g membrane is 35psi and I will be perfectly fine with my ~42psi and they go even further to tell me I would even be fine with dual membranes.
verdict_in
By the time I’m done deciding on an RO unit I’m not going to need a hair cut. I’m going to pull all my hair out.
LOCO<
Maybe if I have another drink I’ll be able to make more sense out of this crap.
ya know that melev’s recommends putting coils of tubing in a heated 5 gal bucket of water to increase the good water and decrease the waste?
I have heard of people doing that in the past and actually did myself once. I still don’t get why RO manufactures don’t sell some kind of heat reactor or something to warm the water up. Perhaps the construction of such a device with the quality of hobby heaters is too large of a legal risk. I might just ask the manufactures and distributers about this question in the future.
Hadn’t thought of this in a while I am glad you brought it up. Thanks moliken.
well, i think a permeate pump recycles some of the brine while filling and pressurizing a storage tank. like this one.
it should work fine on 42 psi , if you run the discharge line to a ball valve for manual control, and then to your RODI storage barrel with the float valve. so that when you dont want to make water, shut off the ball valve. but to make water open the ball valve and the float valve will shut off when the barrel is full. the ball valve is just positive isolation for the down times. you just get the tank in between to satisfy the permeate pump. the permeat pump acts as a shut off ofthe brine discharge when its output pressure equals the tank pressure, or full. or maybe you dont need the tank with the float valve. unclear. think about that when asking the vendors.
According to one of the companies(not AWI) a float valve wouldn’t work with my low 42psi pressure and my storage vat would just overflow. Starting to wonder if everything they on the site and in e-mails is just one big push to sell more booster pumps.
the permeate pump should make a low pressure system like yours or a home well system, work better. the back pressure of the tank will shut it off when they are equaizedl. so the float valve shutting off on the barrel should allow the tank to fill and then shut off the permeat pump and thus the RODI. then to be sure, close the ball valve till next fill. still not sure it needs the tank if there is a good float valve.
melev's recommends putting coils of tubing in a heated 5 gal bucket of water to increase the good water and decrease the waste?
this seems a little counter productive to me. the amount of energy required by the heater to significantly heat the input water would likely would negate any benefits garnered from an increase in efficiency with the amount of output water. of course im assuming that the motivation to increase RODI efficiency is either a)environmental(IE min waste) or b)energy(IE, water bill). Keep in mind that it takes a LOT more energy for the heat to be transferred from the bucket of water to the input water than it would to simply keep the bucket of water warm. It would be akin to leaving the refrigerator door open!
float valve wouldn't work with my low 42psi pressure and my storage vat would just overflow.Jon, your input pressure and your output pressure are two different things. The amount of water in equals the amount of water out, and since your waster water is anywhere between 2-3 times the amount of pure, your output pressure would be between 1/3 and 1/4 your input pressure.
That makes perfect sense to me Shawn, but…
(in a letter from one manufacturer/online dealer): “One note, at your low pressure you will have to run the system manual as the auto shutoff will not work with a float valve at your 42 psi.”
Questioning if I really know how a float valve works or if this guy was under the influence of something while typing or if he would sell his soul to sell a booster pump.
I dont know man, there is a lot to be said for the power of buoyancy ;D I use an AWI float valve in the sump for my turtle tank that is full pressure tap water from my plumbing. I dont know what my pressure is, but the water comes out FAST through the float switch. It definitely wont stop at the normal level so i had to angle it down more to compensate. When the water gets to the point that the float is almost underwater it shuts off and has never failed. I would think that the PSI rating for a float valve would be directly related to the volume of the float. Worse case, you could always grab a big toilet float to replace the RODI float.
[quote=“logans_daddy, post:30, topic:2239”]
melev's recommends putting coils of tubing in a heated 5 gal bucket of water to increase the good water and decrease the waste?
this seems a little counter productive to me. the amount of energy required by the heater to significantly heat the input water would likely would negate any benefits garnered from an increase in efficiency with the amount of output water. of course im assuming that the motivation to increase RODI efficiency is either a)environmental(IE min waste) or b)energy(IE, water bill). Keep in mind that it takes a LOT more energy for the heat to be transferred from the bucket of water to the input water than it would to simply keep the bucket of water warm. It would be akin to leaving the refrigerator door open![/quote]
i disagree here shawn. heating up a 5 gallon bucket of water, to even a really high temp like 90 and keeping it there, while 10 feet of coiled tubing circulates chilly water through it at the speed of a rodi does not take a lot of energy. i don’t know what the potential benefits to more efficient production of water are, that’s melev’s contention, but the energy usage is not great. the fridge analogy isn’t a good one. how about the energy used to keep water boiling slowly [minimal] versus the energy needed to get the same water to a boil [high]? seems to me that is a better comparison.
[quote=“moliken, post:33, topic:2239”]
i disagree here shawn. heating up a 5 gallon bucket of water, to even a really high temp like 90 and keeping it there, while 10 feet of coiled tubing circulates chilly water through it at the speed of a rodi does not take a lot of energy. i don’t know what the potential benefits to more efficient production of water are, that’s melev’s contention, but the energy usage is not great. the fridge analogy isn’t a good one. how about the energy used to keep water boiling slowly [minimal] versus the energy needed to get the same water to a boil [high]? seems to me that is a better comparison.[/quote]
While I think your analogy is better I think the true failure in setting up a a setup like this to heat water and transfer in through pvc tubing to warm the input water is a waste. The energy going in to heat the water for the amount of temp increase in the source water would be minimal.
If you were to coil the input line of the ro/di in you sump during the day as a cooling method (while not totally efficient) wound not cost any additional energy and would heat the source water a bit.
If its an issue with getting the most water out of an ro/di I would get a booster pump and call it a day.
it’s not pvc tubing. it’s that 1/4 inch red, black, white, or clear stuff that comes with the rodi.
source to 5 gal bucket of heated water with coiled tubing in it, to rodi to storage.
i am not claiming lots of savings, just repeating what melev’s reef told me to do to use less water, probably from 4+ gals of waste water to 1 gal of pure, down to 4 to 1. when i was using it straight from my weak pressure sink, it was over 7 to 1.
Paul- i think you would be REALLY surprised. Google a guy named beananimal and look for his thoughts on a DIY refrigarator chiller. He has crunched all of the numbers and proved why you cant use a dorm size refrigerator as a chiller to even make the smallest changes in temperature. Granted, we are trying to do the opposite by heating instead of chilling, but the math is essentially the same because of the law of conservation of energy.
the part that your missing, and why the refrigerator door analogy is the correct one is that your water wont be staying at a constant temp like boiling water. heating the water requires energy, that energy is taken from the bucket of water which is taken from the heater which is likely coming from a coal burning power plant. i know it might be counterintiutive, but its not efficient. first, i doubt that at the proper pressure it would even effect the temp of the water to make a difference. and if it did, i guarentee you that your heater would be CONSTANTLY on. add this to the fact that aquariums are VERY inefficient and draw a LOT more energy than the produce and this is just a BAD idea IMO.
If you were to coil the input line of the ro/di in you sump during the day as a cooling methodnow that IS a good idea, except for we want to heat it and not cool it AL. Again, i agree with you Al. I dont think it would be very easy to change the temp drastically with the pressure associated with the input. However, with a large enough coil(which effects PSI) in the sump i think it would make a difference. Its also much different than a 5g bucket since you would be utilizing the energy produced by lights, pumps, etc. Very efficient. Taking it further, you could put a solenoid on your input on the same time as your lights to better capture the excess heat produced by the lights and assist in cooling.
However, when its all said and done, i feel that any effects using either method would be minimum at best, but the second would at least be efficient. Sounds like a perfect REEFBUSTERS episode!!!
Shawn, I think Al meant you would be warming the water in the tubing via conduction, which would also cool your aquarium. Kill 2 birds with 1 stone…
ah, gotcha.
id really be interested in seeing results. i think what Al said might work, but more importantly, its efficient. im just not convinced that the results would be significant because of the input pressure. the two biggest factors when changing the temperature of water is the intensity of your energy source as well as the contact time between your energy source and target. Conisdering that their could be 20 or more degrees between the input RODI(target) and tank water(source), the intensity is probably sufficient. However, the contact time dictated by the input pressure is going to be minimum. Back to Paul’s analogy, you can boil water with an open flame if the contact time is sufficent. Take the same water, and the same open flame, but expose it for the amount of time determined by the source PSI and its a different story. To extend the contact time, you could extend the length of the coil but the length of the tube is inversely proportionaly to your inital pressure. I havent the slightest idea what the net gain of efficiency would be, but i doubt that it would be worth. However, ive been wrong before:)
[quote=“logans_daddy, post:38, topic:2239”]
To extend the contact time, you could extend the length of the coil but the length of the tube is inversely proportionaly to your inital pressure.[/quote]
Huh? Are you saying that if you have a long tube it would decrease your pressure? If this is do I don’t believe your currect. Not sure exactly what are you saying.
thats exactly what im saying. here is a little blurb from AWI.
NoteIf you have to run tubing over 10 ft (drain vs. product water) it
is best to choose the waste water connection as the long run.*The further you run tubing across any distance the greater the pressure loss due to tubing resistance.
(Maximum recommended run 50Ft) When running tubing up (ie basement to kitchen) you encounter losses due to gravity and tubing resistance.
- For any tubing run over 10 ft we recommend using 3/8 inch tubing
Jon, the length vs pressure is one of the reasons why our water pressure varies so much from neighborhood to neighborhood. Physics again, but anything you can imagine on earth that you need to transport from point A to B needs will deplete energy in doing so. Water, just like electricy and data, loses energy as it is moved from source to destination due to resistance/friction. Also, just like other utilites, there is an infrastructure in place that compensates for this loss of energy(amplifiers, pumps, transformers, etc).
Back to the RODI, i dont personally know how significant the length of the tubing will affect the pressure, but it will. Ironically enough, AWI does suggest to put the tubing in a bucket of hot water, but there suggestion doesnt make sense. They dont even tell you to put in a heat source, the entire comment didnt make sense to me.
Check your PM!