Fertilizing macroalgae

[Nevin]

Hi,

I'm looking for some advice on growing macroalgae faster. I have a small refugium in the sump with plenty of 6700k light on a reverse lighting cycle(picture below). When I transferred to the current tank I used RO water and I have only one fish and don't feed much, so not a lot of nutrients in the water. The chaeto had already shrunken to a tight little ball in the old tank and hasn't grown since. The red macro grows, but has been decimated by my urchin.

Anything I can do to increase growth? I dose a SMALL amount (as I can't test levels) of Flourish Nitrogen. Is growth typically limited by nitrates? CO2? Other? Do I just need to get more fish to fertilize it?

http://i271.photobucket.com/albums/jj151/nmassing/DSC07605.jpg

Thanks for any help,
Nevin

[bassman]

You could try getting the ball closer to the light, build a little shelf or something to bring it up near the surface.

[Dale]

A question, in order to clarify things, is what is your purpose in having the macro in the first place?
Another, more imediate solution would be to remove the urchin and place it in the display so it won't graze on the algae.

[Nevin]

Bassman, I might try that, though I would be surprised if the light weren't enough. It's 18W of 6700K light over about 1-1.5 gallons of water in the fuge area.

Dale, my intent was that the macro would help with nutrient export as my bioload increases. I do realize that doesn't work so well if I'm dosing additional nutrients, though I think it could be useful to dose nitrogen in order to make sure phosphates are used up. Currently, I suppose the main purpose is food for the urchin.

Maybe the urchin is the only problem here. I wouldn't put it back in the display--it's cute, but makes a mess dragging everything around. Could sell it if that's the only answer.

Regards,
Nevin

[spreerider]

i have chaeto in a 10g sump with a 18w bulb, and its growing like a weed, i went from a baseball size piece to a basketball sized in a month. i have a few hermits in my sump (not plummed into main tank yet) and i feed them every few days, i have a hob AC filter with nothing in it running to keep movement while i wait for my pump.

[ferret]

Hi,

Light should be enough and no need to add any additive to encourage the growth of algae, just to maintain a weekly changing of water ( 10% should be enough ) and adding of the 'caulerpa' macro algae in the sump would be good choice for this species supposed to growth fast.

[a4twenty]

A question, in order to clarify things, is what is your purpose in having the macro in the first place?


very good question, and if your chaeto isn't growing that fast is it really a bad thing?????? lack of N & P can't be bad.

i would not dose anything to raise N&P that is just counter productive, and i would never dose anything you aren't / can't test for, always ends bad.

what is the red macro for, get rid of it ( unless it is tang delight for future feeding )

don't add caulerpa, it can be nasty and isn't worth the risk.


chaeto likes a lot of flow, move it up and think tumbleweed :biggrin:

[ferret]

Hi a4twenty,

the caulerpa species are over 50 kinds. The most common types you can obtain are normally easy to control and maintain when you really have the experience to plant them. I have over 20 types of marco algae in my fowlr tanks

[Nevin]

Thanks for all the responses. I have the red macro because it is nicer to look at, the urchin likes it and it outcompetes the chaeto so likely good for nutrient export. There isn't much flow, but I'm not sure I want another powerhead to add heat and take up space.

Seems like the best way to go might be just get rid of the urchin. I'll add another fish soon, which will provide some extra fertilizer too.

Regards,
Nevin

[a4twenty]

the caulerpa species are over 50 kinds. The most common types you can obtain are normally easy to control and maintain when you really have the experience to plant them. I have over 20 types of marco algae in my fowlr tanks

yes but that is one of the problems, it likes ( not all ) to be planted. meaning you have to disturb the substrate to trim ( so it doesn't go sexual ) or risk releasing toxin ( not all but... ) by trimming in the tank.


Seems like the best way to go might be just get rid of the urchin. I'll add another fish soon, which will provide some extra fertilizer too.




if the macro is being consumed in the tank the nutrients are just being cycled but never actually leave the system. you need to trim and remove the macro to actually export nutrients.