This is the testament for reefers. This is AZdRat, he's the man when it comes to water! I'm not downplaying your other skills BTW... I did exactly what he is warning you against, tap water. It was a nightmare and I had a tank pretty much crash... This hobby is best when advice that is sound is listened to and implemented. This doesn't mean you have to buy the most $$$ stuff, but you need to find ways of getting it done. Before I had my own RO/DI, I bought it from LFS, it was a lot of work, but it was worth it to get away from tap water. I ended up finding a used RO/DI for a good price and then replaced the filters and now I have more consistent water.