I've been keeping a few species of rainbows for a couple of years now. As such, I am the local "expert" in our club, the Boston Aquarium Society. We're having a Beginner's Talk this month, several speakers will each be giving short, 10-15 minute talks on a particular set of fish. I'll be speaking on rainbows.
Rainbows aren't new to our club, we had Gary Lange as our speaker last year. He gave an excellent talk.
So I'm putting together a short talk on rainbows looking at Tappin's web site and the Rainbowfish Study Group's site and I've come across some conflicting information.
RFSG says:
Glossolepis, Melanotaenia, and Telmatherina, thrive in hard, alkaline water but typically do not thrive in soft acid water. Iratherina and Pseudomugil come from swampy areas and prefer neutral to slightly acid pH but will survive in more alkaline water. ... Melanotaenia, Glossolepis, and Telmatherina have water requirements that are essentially the same as those for Rift Lake cichlids.
And Tappin says:
The freshwater environments of Australia and New Guinea contain mostly soft water, but their pH and clarity will vary depending on their sediment content and the terrain over which they flow.
I've always heard that they want slightly harder water, and as such have always kept a bit of crushed oyster shell in my filter to keep the calcium up.
So what can I talk my listeners in this very basic intro. Half the group will be beginners but the other half will know the difference between hardness and alkalinity. (Note, I count myself in the third half, the ones that aren't beginners but find some chemistry confusing!)
Thank you.