G'day, I'm Dale. Everything I've managed to work out about keeping corals alive in a tank that sits two metres from my desk ends up written down here, roughly in the order I worked it out, which is not always the order that would make sense to a reader. I'm no marine biologist and there is nothing here for sale — I got thoroughly hooked in the winter of 2019 and never really came good.
Most of this started life as scribble in a spiral notebook that lives next to the sump, and I've only tidied it up far enough to be readable. Where I got something badly wrong I've left the wrong bit sitting there in the middle of the post, because the wrong turns are usually the useful part and I reckon a blog full of tidy successes teaches nobody much of anything.
For about seven months my dKH would drop roughly 0.9 over a week no matter what I did, and every time I chased it with a big dose I'd burn the tips off a perfectly happy staghorn. The answer turned out to have nothing to do with my dosing and everything to do with a tired peristaltic head and a habit of testing at the wrong time of day.
I get some version of this message more than any other: "it's been three weeks and nothing is happening, is my tank broken?" Almost certainly it is not, and I reckon people panic because nobody ever shows them the boring middle stretch. So here is the whole six-week log out of my 38 litre frag tank, real test numbers and all, with none of the ugly days left out.
A Queensland summer will pull four or five litres a day out of an open-topped tank. I spent two years hand-filling a jug and wondering why my salinity chart looked like a mountain range. This is what changed when I finally built a proper auto top-off, including the float switch arrangement I'd use again.
220 litres display, 65 litre sump, running since March 2021. Two clownfish, a royal gramma, a tailspot blenny and heaps more hermit crabs than I ever actually ordered. Mostly soft corals and LPS with a couple of SPS colonies I'm still not confident about. Full list with care notes on the livestock page.
Read the cycling post first and then the top-off one, because between them they cover about eighty per cent of the trouble people write to me about. The chemistry post is more of a rabbit hole and it will keep until something has actually gone pear-shaped on you.
If you've got a question that isn't answered anywhere here, the about page has the ways to reach me written on it. I'm slow, but I do get back to people.
Glass Reef — a hobby diary typed up in a spare room in Brisbane, Queensland. Nobody sponsors it, there are no affiliate links anywhere in it, and there is nothing on it for sale.
Words and photographs © 2019–2026 Dale Prentice. Quote a paragraph with a link back and we are square. Take a whole post without a word to me and I will be quietly filthy about it. Have a chat.
I last had a fiddle with this page on 12 June 2026.