I currently have a spectrapure 90gpd ro unit dripping into my sump of my 600 gal tank, I just got the ro unit about 3 weeks ago and the membrane is already garbage, I talked to the store where I got it from and they didn't understand what I was telling them then they finally realized that I was running it 24/7 so they told me to go with cold sterile ro system but I'm still wondering if I'm gonna need to replace cartridges every couple weeks, just trying to find the best cheapest solution to a 24/7 drip system