I did the same thing with my 30 gallon and regretted not using the Ro water as my algae and phosphates were off the charts. the color of my test was not even on the scale from the test kit!! :scared:
When I upgraded to my 100 gallon, i went to walmart and paid the 25 cents a gallon for their ro water. once it cycled, i got an ro/di unit off that e-"someting" website and have not looked back since.
I now have a 30+ gallon resivoir that is gravity fed to my 20 gallon sump that turns on/off with my float valve.
All of the above equipment has been worth their respective weights in GOLD!!
good luck on your endeavors and keep us posted.
dxtr