Local fish store said to go ahead and start with tap water and use RO for water changes. Will this work or cause any problems? Sure would be easier than getting 55 gallons home. Thanks.
Welcome to the forum!
Start with RO water and do all top off and water changes with RO water.
No sense in introducing unwanted minerals and chemicals into your system.
An RO system would make good sense and would pay for itself in a very short time.
In the long run you will save tons of heartache, time and aggravation!