Ulva not growing well in refugium

[jbilliel]

Mty tank has been up and running for about 6 months and the ulva in my refugium isn't dying, but it's not growing either. I have a kessil refugium light on for 8 hours overnight, but no real growth. Are my nitrates too low and not providing enough nutrients for the ulva to grow?

My tank parameters are

Sal: 35
Alk: 9
Nitrates: 2.5ppm
Phosphorus: 0.06ppm
Calcium: 400
Mag: 1350
Water Temp: 78-79

 

[NashobaTek]

Nitrates could be a little higher. Closer to 5-10 maybe.

 

[Goodair]

I've had this problem too, never figured out why. Closest guess is the chaeto was out competing it as it was growing at a decent rate. My phosphate were much higher but my nitrates were ~5 at the time.

 

[WVNed]

I add iron to my system. I have 2 Viparspectras over this 30 gallon tank with both channels at 90% 12 hours a day.

Sorry I rarely clean the refugium glass.

 

[jbilliel]

Stupid question - in order to increase the nitrates I have to feed more, right?

 

[Goodair]

That's one way about it yes. Some food have more nutritional value then others so whatever you feed will have an impact.