Help with turtle grass

[DaveC]

I'm doing a little research to see if a turtle grass bed would work in my refugium and was wondering if any of you more experienced reefers have had any experience with it.

I've got a 20 gallon display (visible) refugium with a 6" DSB lit by 2 LOA 65 watt power compacts and about 12-13 lbs of LR piled in one corner, and I really just want to add some flora to spice it up visually. It's not intended to be an algal filter really, just a refugium.

Anyway, I got the following information from Inland Aquatics and I wanted to run it by The Reef Tank experts to see what you all think:
"Be sure to plant the Turtle Grass in full light. I highly recommend that you add up some Substrate Gold Nuggets ($6.99) and use BioTrace ($8.99 for 8 oz or $34.99 for 32 oz) after planting your Turtle Grass. The "nuggets" are balls of iron rich laterite that should be placed about 1.5 - 2" into the substrate around the Turtle Grass. The rhizome will greatly benefit from the iron rich substrate. BioTrace will not only greatly increase the rate at which your Turtle Grass grows, but will also benefit your soft corals, mushrooms and zooanthids."

I've never added anything but kalk to my tanks and the suppliments mentioned above have got me second guessing the turtle grass idea. Are they necessary/safe?

Thanks for any imput/suggestions.

[galleon]

Dave,
Iron is a limiting nutrient in much of the vast Pacific that receives little input from airborne terrigenous sediments (major supplier of iron in the ocean). Coastal areas where seagrasses like turtlegrass are present do have iron rich sediments present, and iron, being a limiting nutrient, acts as a fertilizer to photosynthetic organisms, from seagrass to microalgae. While it would be fine to use in your tank, use it sparingly.

Never expose the grass' rhizomes to water or air, make sure they always have silt to sand (10-100 um) sized sediment around their rhizomes. Your sediment should be deep as well, no thinner than probably 5". Biotrace I have no idea about.

Chris

[DaveC]

and iron, being a limiting nutrient, acts as a fertilizer to photosynthetic organisms, from seagrass to microalgae.

Hmmm, I don't know if I should be fertilizing my microalgae.

[fishinchick]

I would love to find out a good source for getting some turtle grass here in S. calif.

I dont think a retail store can sell it to me because its 'technically' a caulerpa. Anyone have any extra they would like to sell privately??

[gregt]

its 'technically' a caulerpa.

Really? I thought it wasn't even remotely related.

[cyberchef]

Originally posted by gregt


Really? I thought it wasn't even remotely related.

You have to remember Greg that in CA anything can be related if they vote on it and pass a law about it... hehehe

[socal surfer]

FishinChick, all of the lfs around where i live selll caulerpa and maidens hair, so i assume that they would be able to get in turtle grass too. I didn't know it was illegal to sell too becuase of the whole outbreak of it in the ocean around here.

[fishinchick]

because its green and leafy and goes in salt water they will associate it.

I have been told by a few LFS's that got busted that its some pretty hefty fines for selling caulerpa or the like in calif.

[socal surfer]

Yeah, the lfs is a hot stake out spot for for those federal agents. hehe

[dark horge]

Sure, Fe in the clay (laterite, they said, right?) will boost growth in your seagrass.

But unless you ensure that the Fe doesn't start leaching into the water, you can expect that the superior ability of micro- and macroalgae to exploit this resource will kick in. I suspect algae (a fair share of which may be unwanted) will be able to exploit the Fe.


Now I've seen seagrasses (Thalassia, Halophila, etc.) being used as a nutrient and general metals scrubber before. The old showcase tank that Doc Walter Adey used to run at the SI in the 80's-90's had a plumbed-in seagrass module. The substrate was just aragonite and settled mulm, and it grew fine, even with a relatively light animal bioload.
It was well lit, and most of the current seemed to be in the top-mid height of the water column (hence the settling).

Obviously if what you're after is seagrass' ability to take up nutrients, you don't want to be ADDING nutrient: keep them lean and hungry for the filth in your tankwater.

The only reason for institutionally adding iron to the substrate is if the water is too nutrient-poor to support the grasses (unlikely if you have a typical reeftank animal-bioload). The typical sewers that we pretend are 'reeftanks' are usually good enough (nutrient-wise) to support them.


jmho



horge

[DaveC]

Thanks Horge, as always. Still interested to hear of any first hand experience (good or bad) with turtle or other sea grasses in an aquarium setting.....

[Spanky]

Dave,

Basically what you need to know - other than all the great info all ready given - is that for turtle grass to stay viable, you would probably have to light it more than you'd want to. It is a light hog, and would need as much or more light than you'd provide your corals.

Since you mentioned using this more as refugia than for export, one of the Halophila would be a much better choice. They will grow in less light, in sandy soil, and lower total organics.

Spanks

[DaveC]

Thanks, Spanky. I was really wonding if anyone would mention the lighting issue. Everything I've read says turtle grass requires "direct" or "strong" lighting but they're kind of vague as to what that means. Comparing it to what we give our corals helps me grasp the the concept. I'll do some reading on Halophila and see what I find and where it might be available.

Thanks for the recommendation. All others are welcome.