I bought a beautiful red crowntail who was prancing and flaring while at the store. I brought him home, put him in a one gallon footed bowl with pretty colored glass and his own little house for hiding and resting. I used tap water with a proper water conditioner.
Within a couple of weeks his lovely tendrils began to curl up. A week or so later his appetite decreased until he was tasting his food and spitting it back out.
Needless to say I scoured the Internet and tried any number of things including numerous different water conditioners — nothing worked.
An aquarium store in my area (North Dallas Aquarium) suggested I try their RO water, so I bought 5 gallons, went home and did a complete water change for my crowntail.
Within 30 minutes he was actively swimming around again. His appetite improved by the next day. With one month of weekly complete water changes using only RO water his tendrils uncurled, he’s building bubble nests and his appetite is good.
This crowntail seems to be particularly sensitive to chemicals. I’m concerned that the RO water is devoid of minerals, i.e., the good stuff as well as the bad stuff; however, it seems to have been the answer for this crowntail.