Fish only with live rock tank, are marine plants a good idea?

Question

I'm new to the salt water tank world and was wanting to know if adding live marine plants to a FOWLR tank is a good idea?
The tank is doing great! The cycle is moving along. The nitrate/nitrite, amonia, pH, etc. are within normal range. Right now a yellow tang, a blenny, 3 damsels, and 10 tiny hermit crabs are residing in a 65 gallon tank. I know fish will like to eat the plants, but with they eat them faster then they can grow? Do plants harm the FOWLR tank?
I

Answer 1

This can depend a lot on the type of "plants" you're planning to get. Most that's available for marine are macroalgaes (except for mangrove shoots). Just like in freshwater, there are "good" algaes and "bad" ones, and even the "good" ones can get to be a pain at times.

Your tang would probably love to have some algae in your tank, as these have a high metabolism and eat almost constantly (if given the opportunity). Damsels would probably also eat some types. Caulerpa is a good choice as it grows quickly (in fact I have to keep mine trimmed so it doesn't overrun the tank). There are a number of types available, some of which have thin leaves, others of which are thick - the texture may influence how quickly it gets eaten.

I suppose your tank doesn't use a sump? That's a great place to grow your algae, and it has some other benefits as well. If you grow the plants in a "refugium", you'll also have a supply of microorganisms that you can use as "treats" for your fish. And since plants undergoing photosynthesis take in carbon dioxide from the water, it raises the ph slightly. If you keep a refugium in a stand under the tank, and use a light on an opposite photoperiod than your tank, it keeps the pH more stable over a 24 hour period. Plants also remove some of the nitrate from the water.

So "plants" can be good for your tank, unless it's a nuisance species like bubble algae, or some of the hair algaes. Also, if you get red algaes, the fish may not eat these as readily - some produce mild acids that make them taste less appealing.

You might get a better idea of the types of algaes that your fish might eat using this link: http://saltcorner.com/sections/guest/algaepage/algaepage.htm - it's actually for nuisance algae identification, and the numbers next to the photos correspond to the organisms at the bottom of the page that eat each type.

Some general info on marine algaes: http://www.wetwebmedia.com/algaeasfriend.htm
http://www.wetwebmedia.com/avoidingalgaeproblesm.htm
http://www.wetwebmedia.com/caulerpaalg.htm