Cyano reactor


New member
My 130 gallon reef has been doing great for over 13 years now. It houses LPS, SPS, some clams, softies 6 different doctor's fish and a plethora of smaller fishes. But my nitrates and phosphates always were a tiny bit on the high side. No big deal. But after al this time, I wanted to perfect it. So, I went with an macro algae reactor.

I got the pax bellum N18. I filled it up with an initial dose of cheato algae. And four weeks later it was all covered in red cyano algae. Weird thing is, I have never ever, in those 13 years seen any cyano in my tank. I actually saw it with my own eyes for the first time in the reactor. I played with high flow and a new seed of cheato, same results. Low flow, longer light period, shorter light period.

And the more I read about it online, the more I really really really want it to work. Not just for the control of organics, but more so for the other benefits.

So guys, what am I doing wrong here?

Here's my specs:
NO3: 2
PO4: 0.03
DKH: 8.3
CA: 440
MG: 1250
PH: 7.6 (I'm trying to raise this... with the algae reactor. LOL)

Michael Hoaster

Registered Seaweedist
Premium Member
You may not have the needed light or nutrient levels to support chaeto growth. As you said, you're very close to 'just right'. The beauty of a macro algae reactor is that you don't see the algae. It doesn't really matter what kind of algae you get. It's not meant to be pretty. It's meant to be an export medium, like a skimmer cup. Do you care what your skimmate looks like? So export whatever you get, and nutrients should go down.

It sounds like you have A LOT of fish in that 130. Six Tangs?! You might try feeding less to see if that helps. Good luck!