Premier Water Systems Portable Counter Top Alkaline Reverse Osmosis Water Filtration System - 75 GPD

Hi, I recently bought a Counter top RO Reverse Osmosis Water Filter System 5 from walmart. we have used it for more than a month now. I did like the filter and the water that we obtain after the 5 stage. I still need to test the water for the parts per million though. The taste is better and we are happy with it. The only concern I have is the speed of the water filter. the water filter is described as 75 GDP which comes to around 3 gallons per hour. But i am afraid we do not even get 1 gallon per hour. we had to run it for more than 2 hours to get a 2 gallon bottle filled. Initially we thought it ll take time to adjust. but even after a month's use the speed is pretty slow. we have a 5 gallon bottle and we have to wait for around 4-5 hours for it to get filled. I wish you could help me here. we stay in an apartment and have many friends who have shown interest n buying similar counter top filters.