Where is my algae coming from?

[jamesgolden5000]

I've had my bare bottom reef tank in place for around a decade, on and off - for a while I had a thriving monti reef with fish which was hit by a plague of monti-eating nudis. Between the monti's dying, and having kids, and the expensive reef lights breaking I did the sensible thing and let it become a fish only tank with regular lights etc, with mainly my tomato clown and 2-3 other small guys. The tomato passed away after 20+ years last year and I decided to do two things: start doing corals again but do it with no fish whatsoever. My prior experience told me trying to have a reef with fish is a constant battle between nutrients in and out, and although I was pretty successful with Montis until the nudis got in, I wanted this evolution of the tank to be a bit easier to manage.

Lights have gotten much cheaper and I got some decent amazon reef lights which seem to work fairly well. But early on I noticed I was getting dinos. I realized that when my tank went to fish only, I stopped using RO/DI, simply because it was easier and faster to do water changes. So I updated my RO/DI and for the last few months have ONLY been using that. Since this is a coral only tank, I basically don't feed it at all. I've maybe added a tiny amount of reef roids once in the last three months, maybe about 1.5 months ago. The corals don't seem to need it so I don't really plan on using it at all going forward.

Here's the problem. I have been doing weekly water changes, I use a pump to stir up any crap from the bottom and skim and I've gotten a cheap water polisher to help remove any of the crap stired up. I run carbon, poly-filter pads and chemi pure, but seem to have a burgeoning hair algae issue.

I'm not feeding, haven't feed in well over a month and haven't fed more than a pinch of reef roids in three months. How the heck is hair algae growing in this situation?

 

[BryanM]

I've had my bare bottom reef tank in place for around a decade, on and off - for a while I had a thriving monti reef with fish which was hit by a plague of monti-eating nudis. Between the monti's dying, and having kids, and the expensive reef lights breaking I did the sensible thing and let it become a fish only tank with regular lights etc, with mainly my tomato clown and 2-3 other small guys. The tomato passed away after 20+ years last year and I decided to do two things: start doing corals again but do it with no fish whatsoever. My prior experience told me trying to have a reef with fish is a constant battle between nutrients in and out, and although I was pretty successful with Montis until the nudis got in, I wanted this evolution of the tank to be a bit easier to manage.

Lights have gotten much cheaper and I got some decent amazon reef lights which seem to work fairly well. But early on I noticed I was getting dinos. I realized that when my tank went to fish only, I stopped using RO/DI, simply because it was easier and faster to do water changes. So I updated my RO/DI and for the last few months have ONLY been using that. Since this is a coral only tank, I basically don't feed it at all. I've maybe added a tiny amount of reef roids once in the last three months, maybe about 1.5 months ago. The corals don't seem to need it so I don't really plan on using it at all going forward.

Here's the problem. I have been doing weekly water changes, I use a pump to stir up any crap from the bottom and skim and I've gotten a cheap water polisher to help remove any of the crap stired up. I run carbon, poly-filter pads and chemi pure, but seem to have a burgeoning hair algae issue.

I'm not feeding, haven't feed in well over a month and haven't fed more than a pinch of reef roids in three months. How the heck is hair algae growing in this situation?

Are you testing any tank parameters? If so, what are they?

Any tank pics? Any natural light hitting it from close by?

 

[jamesgolden5000]

Parameters are pretty good but I haven't done a recent test. I'll try to gather some numbers tonight but I'm doing weekly water changes, skimming, running carbon, chemi pure and NOT FEEDING so I really don't get it.

Here's a pic. This is an in-wall tank visible on both sides. While there is natural light, the sun does NOT directly shine on the tank ever - only indirect light. You can see tufts of algae at the bottom and notice there is some stuff on the glass even though I last did a glass scrape and water change Thursday.

.

 

[BryanM]

So if you look at the pic you posted, we can't see anything... Way too dark and blue, likely need white light pics.

Can you post tank age and parameters please?

How far away is the natural sunlight?