Seaweed in tanks?

"Seaweeds" are becoming increasingly popular. They include true vascular plants (seagrasses), and simpler macroalgae. The macroalgae are more common, being found attached to rocks in many environments, as well as sandy bottoms, while seagrasses are usually restricted to sandy bottoms where they can take root.

As a general rule, macroalgae are easier to keep. They need less light, and do not need a deep, nutritive layer of sand. They are a hugely diverse group, covering at least three phyla, and have a wide range of temperature and lighting requirements/tolerances.

Sea grasses tend to be a little trickier. Depending on the species, you will want a 8-15 cm bed of sand, preferably enriched with marine mud. They require more intense light, especially because they also will require a tall tank to accommodate their growth.

Both work well for nitrogen uptake. They are also used decoratively, and to give a place for small invertebrates to breed.

There is a lot of scientific literature regarding the light requirements, nutrient uptake and growth rates of many species. You might find a common local species that looks promising and hunt the databases for whatever information is out there.

Tropical tanks are kept anywhere from 76-85 degrees F (25-29 C). Coldwater tanks, are somewhat rare but increasing in popularity. Chiller are becoming less expensive, so people are starting to seriously explore the possibilities of temperate tanks. A lot of shallow water plant species are much more tolerant, so you may do fine at room temperature.

Here's an article you may find helpful: Marine Plants

Keep the questions coming!

Be careful.Alot of times sea plants introduce certain types of nuisance algae as well as other undesirables.
I once added halimeda to my fowlr and it took me over a year to rid the tank of the hair algae hitchiker it introduced.

Just for kicks, here's a pic of my 65g. I set it up as a FOWLR, but (as most people predicted) I'm slowly converting it to a reef. I started with a few little bunches of Caulerpa racemosa macroalgae and here's what's happened:



Obviously I need to harvest some of this stuff out, but generally speaking I like having it in the tank. I do worry about it 'going sexual' and fouling the water, but it takes up N and P like nothing else and provides wonderful hiding places for lots of critters that come out at night. I have no idea if they came in with the LR or the macro, but I've got many stomatella snails, some unidentified snails that look like white bumblebee snails without stripes, and pods that all seem to stay within the Caulerpa for safety.