Is this diatom or dino? (5 month old mixed reef)

Phyber · Oct 14, 2019

I have a mixed reef tank of about 65g total water volume. I've been doing biweekly 20g water changes and the tank had been looking great.

I got a bit lax on the changes, and at the same time had a BTA rapidly decline in health and eventually get chopped up in my powerhead.

The BTA got chopped last Wednesday, but I had been seeing this algae appear on the sand bed a bit before and now it's getting heavy. I've done two 20g changes since, and another would be about a 100% change.

I already had a diatom outbreak, but is this a resurgence? I tried siphoning the sand bed but never got the algae to get sucked up. I gave up and just turned the sand over but this stuff came back within about an hour.

Bramzor · Oct 14, 2019

Phyber said:
I have a mixed reef tank of about 65g total water volume. I've been doing biweekly 20g water changes and the tank had been looking great.

I got a bit lax on the changes, and at the same time had a BTA rapidly decline in health and eventually get chopped up in my powerhead.

The BTA got chopped last Wednesday, but I had been seeing this algae appear on the sand bed a bit before and now it's getting heavy. I've done two 20g changes since, and another would be about a 100% change.

I already had a diatom outbreak, but is this a resurgence? I tried siphoning the sand bed but never got the algae to get sucked up. I gave up and just turned the sand over but this stuff came back within about an hour.

You don't happen to have a microscope? That's the easiest way to identify dino's. I thought there was also a trick to test them out of the tank, not sure what it was but it would change to a specific color when dripping on a specific liquid.