Macroalgae Growing Tips?

[genesisblue]

Hey all,

I'm trying to set up a macroalgae tank in order to provide fresh food to my tangs. I have a 20 gallon long with a power compact 80 watt total...it has a 12k daylight and a actinic. I also have one of those "daylight" desklamps over it. I have filled the bottom of the tank with that Florite freshwater gravel as well as some live sand from my main tank. I am currently growing chaetomorpha and the little grape bunch looking algae (i forget the name at the moment). I have a good protein skimmer on it, an air pump, and good current in the tank. However, my nitrates are at 0 dispite my mega feeding with generic fish food. My question(s) is/are: What else can i do to make the algae grow more? (I also have it on a 24 hour light regimen). I can grow coral and fish, but for the life of me, I can't grow macro algae. All my parameters are fine for a normal inhabited tank. Do I need to add some damsels to dirty the water up? Any advice will be greatly appreciated and showered with praise


Thanks!
Adam

 

[george]

Freshwater gravel should not be used in a saltwater aquarium because it can leach salts and metals into the water as well as the size being a trap for detritus. If you can't supply at least 3" of marine sand for the bottom, you're better off just leaving it out.

What you want to establish is a refugium. Ideally, plumb it into your main tank to help feed the tank with copepods and isopods which will grow in there along with the macroalgae. It will also serve as a small amount of nutrient export and, if you have the 3"+ sand bed, denitrification.

You don't need to skim it at all. Even if you don't plumb it into the main display, the skimmer is removing nutrients the plants can use.

The lighting is fine wattage-wise, but I would replace the bulbs with ones in the 6500K range for optimal plant growth. You can also buy the GE compact fluorescent bulbs such as

 

[soarin']

Are you growing grape caulerpa in there? If so, pull it out before you change out the substrate. You can get a 40 pound bag of oolite grade aragonite sand at a pet store for $20, and it will do you a world of good.

I got a tank from a guy who used grape caulerpa in the refugium, and I removed it all in favor of chaetomorpha months ago -- but the spores are still in the system and it constantly tries to restart itself and will take off like a rocket at the first opportunity.

The macro-algae guy at MACNA said that Seachem Flourish is a wonderful product for growing macros.

Someone said that they got very good results at growing chaeto with a 5100k bulb.

 

[fishgardener]

I don't know which kind you have, but some of the grape caulerpa are invasive species, so if you choose to get rid of it, don't throw it down the drain. It is recommended to put it in the freezer to kill it. Then you can trash it. Some varieties can survive days out of the water and regrow from tiny amounts. Good luck growing macroalgae. Mine grows really slow-I have too much flow.