Here's my experience with my RO/DI and my need for a booster pump.
I purchased the 5 Stage RO/DI Standard for $159 from Bulk Reef Supply in order to fill my first 72g saltwater tank. I later figured out that a slow trickle of water droplets (more on that in a minute) was not the desired flow from a 75 gallon per day (gpd) system.
At this point I did not have a pressure gauge and dual TDS monitor which came on the Plus unit, so I added them to my cart which brought me up to the price I would have paid for the 5 Stage Plus system that also includes the Flush Kit. Lesson learned, should have gone for the upgrade in the beginning. :embarassed:
So here's my math and why I decided to also add in the booster pump to this second order:
Now I'm no expert, but my thinking leads me to believe that if I don't have the correct pressure inside the RO membrane some solids could get around the membrane if it is not properly pressurized, and I'm also wasting a lot of water because it just doesn't have the pressure to go through the membrane, so it gets bypassed into the waste water line.
Once I got my pressure guage, TDS monitor, and booster pump it was time for another round of experiments! Man I love this! ...I actually do, I'm a nerd, can you tell?
Ok, so background before the dry math.
I installed the pressure gauge. My house was pressurizing the RO at 45psi; not too shabby. So now we know at 45psi I was producing 37gpd of water with about 3ppm of TDS (because I just measured it with the TDS monitor; figured I'd skip that installation bit).
The directions for installing the 1/4” Aquatec 8800 Booster Pump *KIT* (purchased from BRS for $140) were very simple. Almost too simple because with electricity, pressure switches, and adjustable screws for pressure, I was left wondering what would happen once I turned it on.
So installation complete, I closed my eyes (not really) and turned on the pump. Immediately the input pressure to the RO spiked to 125psi! WAY TOO HIGH FOR THE 75GPD RO! At that pressure the .6 micron canister sprung a leak. I quickly shut off the pump and decided to try my luck with the bypass screw on the top of the pump. (of which there are no directions anywhere on the manufacturer's website or BRS!)
I turned it back on (still at 125psi, and a leak) and put in the allen key and started turning it counter-clockwise. I could then easily tune down the input pressure to 80psi. This is as low as it will go. Problem solved! No more leak, and a nice steady stream exiting the RO/DI system. Time for the math, I'll do it a bit quicker since you hopefully got used to my weird way of doing math last time.
1:54minutes for 12oz in seconds = 114s
114s x 10.6 = 1208s/g ÷ 60s = 20m/g (minutes per gallon)
1440mpd ÷ 20m/g = 72gpd
So this meant that at my current rate (with a booster pump and input pressure of 80psi) I was filling my tank at a flow rate of 72 gallons per day (gpd). That's almost double what it was earlier at 45psi!
Also, with a better input pressure and better output, my TDS went down from 4ppm to fluctuating between 0 and 1ppm. That's with an average of 130ppm on the input line.
Sorry it took so long to get here, but I can't recommend something without first showing how I got to that way of thinking.
Hope this helps someone! If not, I hope I didn't kill you with boredom from the math!
Here's some pictures to make you feel better:
I purchased the 5 Stage RO/DI Standard for $159 from Bulk Reef Supply in order to fill my first 72g saltwater tank. I later figured out that a slow trickle of water droplets (more on that in a minute) was not the desired flow from a 75 gallon per day (gpd) system.
At this point I did not have a pressure gauge and dual TDS monitor which came on the Plus unit, so I added them to my cart which brought me up to the price I would have paid for the 5 Stage Plus system that also includes the Flush Kit. Lesson learned, should have gone for the upgrade in the beginning. :embarassed:
So here's my math and why I decided to also add in the booster pump to this second order:
I timed the speed in which the RO was filling a 12oz cup: (m=minutes, s=seconds, g=gallon)
(10.6x12=128= ounces in a gallon)
(24 x 60=1440 minutes in a day(mpd))
3:41minutes for 12oz in seconds = 221s
221s x 10.6 = 2343 s/g ÷ 60s = 39m/g (minutes per gallon)
1440mpd ÷ 39m/g = 37gpd
So this meant that at my current rate (without a booster pump) I was filling my tank at a flow rate of 37 gallons per day (gpd).
(10.6x12=128= ounces in a gallon)
(24 x 60=1440 minutes in a day(mpd))
3:41minutes for 12oz in seconds = 221s
221s x 10.6 = 2343 s/g ÷ 60s = 39m/g (minutes per gallon)
1440mpd ÷ 39m/g = 37gpd
So this meant that at my current rate (without a booster pump) I was filling my tank at a flow rate of 37 gallons per day (gpd).
Now I'm no expert, but my thinking leads me to believe that if I don't have the correct pressure inside the RO membrane some solids could get around the membrane if it is not properly pressurized, and I'm also wasting a lot of water because it just doesn't have the pressure to go through the membrane, so it gets bypassed into the waste water line.
Once I got my pressure guage, TDS monitor, and booster pump it was time for another round of experiments! Man I love this! ...I actually do, I'm a nerd, can you tell?
Ok, so background before the dry math.

The directions for installing the 1/4” Aquatec 8800 Booster Pump *KIT* (purchased from BRS for $140) were very simple. Almost too simple because with electricity, pressure switches, and adjustable screws for pressure, I was left wondering what would happen once I turned it on.
So installation complete, I closed my eyes (not really) and turned on the pump. Immediately the input pressure to the RO spiked to 125psi! WAY TOO HIGH FOR THE 75GPD RO! At that pressure the .6 micron canister sprung a leak. I quickly shut off the pump and decided to try my luck with the bypass screw on the top of the pump. (of which there are no directions anywhere on the manufacturer's website or BRS!)
I turned it back on (still at 125psi, and a leak) and put in the allen key and started turning it counter-clockwise. I could then easily tune down the input pressure to 80psi. This is as low as it will go. Problem solved! No more leak, and a nice steady stream exiting the RO/DI system. Time for the math, I'll do it a bit quicker since you hopefully got used to my weird way of doing math last time.
1:54minutes for 12oz in seconds = 114s
114s x 10.6 = 1208s/g ÷ 60s = 20m/g (minutes per gallon)
1440mpd ÷ 20m/g = 72gpd
So this meant that at my current rate (with a booster pump and input pressure of 80psi) I was filling my tank at a flow rate of 72 gallons per day (gpd). That's almost double what it was earlier at 45psi!
Also, with a better input pressure and better output, my TDS went down from 4ppm to fluctuating between 0 and 1ppm. That's with an average of 130ppm on the input line.
* A note on the Auto Tank Shutoff switch: there's a tiny allen key screw that you have to turn counter-clockwise in order to get it to shut off at the same time or slightly before the auto shut-off that's built into the RO/DI unit. I had to turn it back about 4-5 complete revolutions to get it to shut off at the correct point. You can see how far backed out the screw is.
Sorry it took so long to get here, but I can't recommend something without first showing how I got to that way of thinking.
Hope this helps someone! If not, I hope I didn't kill you with boredom from the math!



