So, I just bought the 75gpd Typhoon 5 Stage Reefkeeper from AWI. After getting the unit, I was reading over the paperwork and noticed that it mentioned that the unit makes 75 gpd given the right water temp and pressure… It said for every 1 degree your water temp is below 77degrees, it loses 1.3% output.So… I had a couple of questions…
Who has cold tap water that comes out of the tap at 77degrees?? Most well water comes out of the ground at between 50 and 60 degrees (something like 52 i think??) That being said, because my water generally comes out of the ground at 52 degrees, I am going to actually get something like 42 gpd out of this unit (77-52=25 degree difference… 25 x 1.3 = 32.5gpd less than optimal… 32.5 - 75 = 42.5 gpd) at 50psi. That is considerably less than what I was expecting to get.
I haven’t read anywhere what the maximum temperature is that you can put through these RODI’s. I don’t want to necessarily put 150 degree water out of my water heater into the tank, but… can you?
Has anyone with an RODI attempted to combine hot and cold water inputs somehow, to get above 77 degrees? I envision some sort of clothes washer hookup that the hot water is partially turned on in order to get 75-80 degree water out of. This would be somewhat easy for me to do since I am going to mount my RODI unit in my crawl space directly below my fish tank, which happens to share a wall with my guest bathroom. So, hot and cold water run almost perfectly in line with where I’d like to put my RODI Unit.
Last question… Since I won’t be installing my RODI unit under a sink, I have to find a way to dispose of the waste water. Initially, I am going to send the waste water to my septic system, however this summer I plan on putting a storage tank that my wife can use to water her flower and herb gardens with. My only concern is that since I won’t be placing the waste connection on the ‘upside’ of the pea trap under a sink, is there any concern with the gases coming out of the septic lines affecting the water in the RODI, or the RODI itself?
As far as the water temp goes I’ve heard of people coiling their “inpuit” line for the RODI in a bucket of water with a tank heater. It’s not ideal but if there are enough coils it should heat it up enough to make the unit more efficiet.
Another means is to add a booster pump to the inlet side of the unit.
I don’t think you have to worry about the gases from the sewer line. I’d just mkae sure that whatever connection you sue is airtight and can not run the risk of “backwashing”
[quote=“Cdangel0, post:3, topic:3791”]
As far as the water temp goes I’ve heard of people coiling their “inpuit” line for the RODI in a bucket of water with a tank heater. It’s not ideal but if there are enough coils it should heat it up enough to make the unit more efficiet.[/quote]
I believe I am already getting a decent amount of water pressure, probably somewhere in the range of 60psi, but I’d have to double check it to be 100% sure. I don’t know that adding a booster pump to get the extra 15psi is worth the extra money… I’ll have to double check my psi though.
I wouldnt bother trying to heat the water. 3/4 of all the water is going down the drain anyway so your paying for heating alot of waste water. Membranes do have a max temp. Cant say what your max is without looking at the spec’s for it but most max out at about 115*f
Ya know… the more I’ve thought about it, I am only going to be using RODI water for top offs and for water changes (20 gallons a month)… (other than using it this weekend to fill up the 75gallon tank and 20 gallon sump my little bro and I are setting up at our parents house). So for topoffs I won’t notice the difference between 75 and 42 gpd because its being controlled by a float switch, either way its only running for a few seconds before shutting off. For water changes, it’ll make a little less than 2 gallons an hour as opposed to 3 gallon an hour, so it’s not THAT big of a difference. Either way, I am going to have to start it and walk away. I guess I was just wondering if anyone else did anything to make their RODI more efficient and max out the GPD. verdict_in
[quote=“ihuntinde, post:1, topic:3791”]
So, I just bought the 75gpd…
Who has cold tap water that comes out of the tap at 77degrees??[/quote]
Almost no one - but we do hear from customers in the south who do!
2. I haven't read anywhere what the maximum temperature is that you can put through these RODI's. I don't want to necessarily put 150 degree water out of my water heater into the tank, but... can you?
Temperatures over 113 will void the warrnaty on a Filmtec membrane. For context, anything over about 106 is uncomfortable to stick your hand in.
3. Has anyone with an RODI attempted to combine hot and cold water inputs somehow, to get above 77 degrees? I envision some sort of clothes washer hookup that the hot water is partially turned on in order to get 75-80 degree water out of. This would be somewhat easy for me to do since I am going to mount my RODI unit in my crawl space directly below my fish tank, which happens to share a wall with my guest bathroom. So, hot and cold water run almost perfectly in line with where I'd like to put my RODI Unit.
It is possible to do this, but realize that the temperature coming out of that mixer can change significantly when for instance someone turns on the sprinklers, flushes a toilet, etc. So if you are going to do this leave yourself a big margin of error so that hot water never hits the membrane.
4. Last question.. Since I won't be installing my RODI unit under a sink, I have to find a way to dispose of the waste water. Initially, I am going to send the waste water to my septic system, however this summer I plan on putting a storage tank that my wife can use to water her flower and herb gardens with. My only concern is that since I won't be placing the waste connection on the 'upside' of the pea trap under a sink, is there any concern with the gases coming out of the septic lines affecting the water in the RODI, or the RODI itself?
I'm not clear on why you wouldn't plug the waste water tube into the drain above the ptrap?
the colder the water the better the membrane functions it is slower but it has lower tds. I had a sink kit hooked to one with a filmtec membrane i adj. the water temp to 100 and it made water fast at 24tds then cold at 50 and water tds was 4 so i would rather have better water at a slower rate if you want water ready all the time you can get a storage tank up to 30 gallons it is a ro safe bladder tank like a well tank. then di it when you use it
Remember that RO membranes function based upon the difference in the pressure on the feedwater side of the membrane versus the pressure on the tank side of the membrane.
So for sake of discussion let’s say you have 50 psi tap water and your RO water goes to a 5 gallon bucket at 0 psi. So the membrane is operating at 50 – 0 = 50 psi net driving pressure.
Now, if you have your RO water delivered to a pressurized tank, when the tank is full it will provide pressure back against the membrane at 66 to 85% of the feedwater temperature, so 50 psi – about 38 psi = 12 lbs of net driving pressure. You can imagine what sort of rejection rate you’ll see at 12 psi.
So the TDS of RO water in a full tank will be substantially higher than the TDS from an atmospheric (unpressurized) tank.
There are some other issues that play into the calculations here but you get the drift.
I use a drinking Ro system it’s Hague got it from work. It comes with the 2 gallon storage tank I tee’d in another 20 g storage tank, I removed the shutoff valve and installed the permeate pump to get house pressure on the tanks also I prefilter the house water. My house tds is 150-160 out of the Ro it is 7-10 out of di of course 0. I do get tds creep from short cycling the system since the shutoff valve is removed. But I am happy with it now, I wasn’t happy with the shutoff valve in there due to the icecube tray not filling completely at all times. It’s only a 24 or so gpd. I changed the filters after 2 years and they still looked clean I sanitized it and left the membrane, it is now 7 years old. But tds is the same as new. I know it’s weird but it works well. Does it make sense that the membrane lasted so long?
[quote=“dunk, post:15, topic:3791”]
I use a drinking Ro system it’s Hague got it from work. It comes with the 2 gallon storage tank I tee’d in another 20 g storage tank, I removed the shutoff valve and installed the permeate pump to get house pressure on the tanks also I prefilter the house water. My house tds is 150-160 out of the Ro it is 7-10 out of di of course 0. I do get tds creep from short cycling the system since the shutoff valve is removed. But I am happy with it now, I wasn’t happy with the shutoff valve in there due to the icecube tray not filling completely at all times. It’s only a 24 or so gpd. I changed the filters after 2 years and they still looked clean I sanitized it and left the membrane, it is now 7 years old. But tds is the same as new. I know it’s weird but it works well. Does it make sense that the membrane lasted so long?[/quote]
Sure. We know someone who’s had a membrane for 12 years!