Photosynthasis in marine tanks

[waterdog]

Hello, I wish to create a marine tank that relys on photosynthetic plants/algae to clean the water. Basically I want to create the refugeum effect within the display aquarium. I dont need a huge variety of fauna, I just would like to create A mini biotope within the display tank. Has anyone had experience with this? I have had great success in freshwater with this, and would like to replicate the success in marine.

Any comments/suggestions would be appreciated.

JP

;)

[Ninong]

Hi waterdog, welcome to Reefland!

Be sure that you do not include any herbivores that would eat your algae. You would have to harvest a huge amount of algae on a regular basis for it to have any noticeable effect on the export of nutrients. You might try setting up a tank with lots of live rock and a nice deep aragonite sand bed. If you have only a few small carnivorous fish, it might be possible to operate without any other filtration.

[tussinhead]

What plants are recommended for display tanks? I hear a lot about caulerpa and mangroves in refugia, but I rarely hear about plants in marine display tanks. The selection on liveaquaria.com is pretty limited, too.

[Ninong]

What plants are recommended for display tanks? I hear a lot about caulerpa and mangroves in refugia, but I rarely hear about plants in marine display tanks. The selection on liveaquaria.com is pretty limited, too.

That all depends on whether you intend keeping any corals in your marine display tank. If it will be a fish-only tank with a sand bed, some live rock, plants and algae, then your choices are pretty much wide open. If you intend keeping corals, then you have to consider the effect of toxic turpenes and other chemicals associated with caulerpa and other algae, to say nothing of the problems associated with the algae overgrowing the corals.

I wouldn't recommend caulerpa for a tank with corals. You might want to limit your choices to something safer like halimeda. Then all you would have to do is make sure it doesn't get out of hand. Another benefit would be that very few fish will eat it.

There are some very nice lagoonal tanks at the Waikiki Aquarium in Honolulu that have lots of seagrasses and mangroves. I don't believe they had any corals in those tanks but they did have lots of fish. Marine plants do help with filtration to a certain extent but not as much as marine algae that can be harvested and "exported" from the system. Mangroves are nice but they are more for show than anything else.

[tussinhead]

Thanks for the reply, Ninong. And sorry to hijack your thread, waterdog. I don't plan on keeping any corals, so I'm not limited there. I already have some halimeda, and I've seen caulerpa for sale, but I want more variety. I understand mangroves need an open-top tank, so that's out. What else is available? I'm not worried about the filtration aspect, either. I just want it for looks.

[ick sucks]

algae turf scrubbers are more efficient than caulerpa. harvest algae in a sump and remove it when it grows too much.just keep snails in your display to keep the algae from taking over your main tank.

[Reefland]

algae turf scrubbers are more efficient than caulerpa. harvest algae in a sump and remove it from the tank to make better use of the filtration. just keep snails in your display to keep the algae from taking over your main tank.

I'm not clear on what you are recommending here? Harvest algae in the sump and remove it from the display to make better use of the filtration? Obviously if you use algae to export nutrients, it is better to keep it in a separate vessel so it don't take over the display and make it an eyesore, but it isn't making any better use of the algae regardless of where is it located. Additionally, snails are not going to eat Caulerpa but they are helpful in keeping the display clean of various nussience algaes.

[Ninong]

I don't think ich sucks understands what an algal turf scrubber actually is. He seems to be confusing it with growing and harvesting macroalgae in a sump.

[Reefland]

Maybe that's what it is. ick sucks, are you using macro algae in your sump for nutrient export or are you using a true algae turf scrubber as they are completely different? True ATS's utilize microalgae in a very shallow tray with system water running through it and more modern forms of refugiums used for nutrient export utilize macroalgaes in small aquariums that also usually contain liverock and DSB's.

[ick sucks]

i use a sump with algae growing on a screen. i also have caulerpa growing in the sump. i scrape my screen every 2 weeks, and remove caulerpa every so often. hope that helps. its more like a refugium rather than an ats,but it does the job.

[tussinhead]

Ahem!

While EXTREMELY interesting, could we possibly push the discussion on algal turf scrubbers aside for a moment and get back to suggesting some good display tank plants for me?!?

Thanks!

[Ninong]

Ahem!

While EXTREMELY interesting, could we possibly push the discussion on algal turf scrubbers aside for a moment and get back to suggesting some good display tank plants for me?!?

Thanks!

The truth is that there are virtually no plants that are really suitable for reef tanks and only a few that are small enough to be suitable for fish-only type aquaria. There are a few species of macroalgae that are tolerable in marine tanks if their growth can be controlled but that is easier said than done. Certainly many species of algae can cause problems in reef tanks for the reasons I mentioned earlier in this thread.

There just isn't the saltwater equivalent of a Dutch tank or an Amano tank in the marine hobby because the number of saltwater plants in the wild is EXTREMELY limited compared to freshwater plants. The most common saltwater plants are flowering grasses.

Besides, if you have a standard size 29-gal tank and all you have is a total of 60 watts of normal output fluorescent lamps, you do not have sufficient light intensity for ANY marine plants. Marine plants are found in shallow coastal areas with intense sunlight.

Perhaps you should try to find some low light-tolerant species of macroalgae instead?

[tussinhead]

Well, that is a bummer. I guess I'm stuck with my Halimeda. It seems to do pretty well even with just the 60 watts of NO. I think I'll get some more of it, and maybe I'll try some of the seagrass that grows locally around here to see how that does. I'll let you know.I'll look into the macroalgae, and will report back on that, too.

As always, thanks so much for your replies, Ninong.