What type of plant would be good for my refugium? I have been looking at Caulerpa and Shaving Brush Plant. Would these be good for helping to remove nitrates?

I would stay away from Caulerpa as it has the tendency of going "sexual" meaning it releases nutrients back into the water. I would go with Chaetomorpha as it seems to be the best Macro Algae that I've found and many people prefer it over other types. Seacrop sells Chaetomorpha for different prices and shipping I believe is only $10.

Chaeto is the best nutrient exporter for a saltwater tank and it's very hardy. Other macroalgaes can also be used. Caulerpa should only be put in established, stable environments. I have about three types of caulerpa and one type regularily goes sexual (a few strands once every two months).

How do u tell when Caulerpa goes sexual?? It was all i could find locally. I have put some in my refugium.
I really needed something to help with my nitrates.All my other readings are good. Just the nitrates are higher than i want.

If your macro's tips and part of the root start turning white, then it's going sexual. It can happen a lot of ways, and can do many types of things at the same time.

1. It can just die off.
2. It can die off for a bit than burst back up and take over your tank.
3. It can turn white and release nutrients back into your system.
4. It'll just plain out dissappear.

A lot of the times it'll just do odd things. When it goes sexual though, if you have large amounts, it will release nutrients and can effect your ph.