Re: Re: Re: RO/DI replacement filters
Re: Re: Re: RO/DI replacement filters
<a href=showthread.php?s=&postid=14187299#post14187299 target=_blank>Originally posted</a> by bad santa
Can you give me the condensed version of why i should stay away from the 100gpd membrane.water.
The 75 gpd membrane will save you money on the DI resin which costs the most to replace
The major difference is in the rejection rate and the life of your DI cartridge. All of our reefkeeping systems are designed to make -0- tds water. The 75 gallon per day membrane is rated to reject about 98% of the TDS. The 100 GPD Membranes is rated at about 90%. That difference changes the amount of work the DI has to do. The non rejected TDS is mopped up by the DI so the less mopping up to do, the longer the DI lasts. A DI cartridge is rated at 6,800 PPM Divide the 6,800 by the output of the membrane to guesstimate the number of gallons you can expect from the DI.
Example: Tap water 200PPM. The expected output of the 75 gpd would be 6-12 ppm. The expected output of the 100 gpm would be 20-40 ppm. Actual values are dependent on you tap water quality, pressure and temperature. 6800 > 12 = 566 gallons 6800 > 40 = 170 gallons.