What growth rates should I expect?

[bploeg]

Hi,

I've started stocking my DIY 59G acryllic refugium. It has
a bottom of about 1.5" of crushed coral with another 2-3"
of CaribSea Araga-Mud. It has a 2x65W 6700k PC (24x7)
for lighting and 1200G/hr flow rate..

I stocked my refugium with Long and short Feather Caulerpa
from IPSF 3 wks ago. At first both seemed to die, but since
then they have started showing signs of growth. However
I am disappointed with the rate of growth. I have maybe 10
'feathers' each between .25' and 1" long and the growth
does seem to stall at that length. I understand growth rates
will vary based on conditions, but does this sound like a 'problem'?

-B.

 

[kmk2307]

Hey bploeg,

I don't know if I would say you have a problem but growth rates like that aren't going to really have much of a beneficial effect on your tank. Do you test your water? If so, how is it testing out to be? Perhaps your nutrient levels are too low. That should be decent lighting but more wouldn't hurt the growth. I would avoid pruning the plant.

HTH,
Kevin

 

[piercho]

When I kept caulerpa I always found it to grow pretty quickly, even with low nutrient levels in the water. Your flow rate sounds fine. The light should be adequite if it's really making it into the tank: mounted close with good reflectors.

You may just have very low nutrient levels in the tank right now. Testing N and P and watching plant growth in the main tank should give you an indication.

I add chelated Fe daily, and find some plants hard to maintain without adding it. If your tank is Fe-limited, adding a chelated iron supplement should give you dramatic results. For greens like caulerpa, the plant darkens up and growth really takes off. I use to use Kent's iron supplement, but have switched to Azoo Chelate Ferrie because it doesn't also add manganese (like Kent's), and because Drs F&S had a good deal on gallon jugs of it

You might also try adding additional genera of algae to the refugium. Chaetomorpha is a good candidate. Inland Aquatics sells refugia plant kits with other plants beside caulerpa. Conditions in the tank are cyclic, at any given time some plants will excell while others lanquish. A few months later, the same plant that showed very slow growth may go through a period of strong growth.

One last thing about caulerpa. In a study of 2 specie of caulerpa, the N ratio of the tissue was found to be unusually high, at around 200:1 [S.T. Larned, 1998]. A number like 20:1 is typical for most green plants. As a part of the same study, caulerpa was grown under conditions of elevated N, elevated P, and elevated N&P. Caulerpa responded poorly to elevated P, showing retarded growth. Since it is mainly phosphate most of us are trying to bind in our export, Caulerpa may be one of the poorest choices for that purpose.

 

[bploeg]

Very interesting! I will order some of the products you are suggesting. I lowered the lights as close as possible
to the surface. BTW it is a coralife fixture so the reflector
should be ok.
Since I was using Araga-Mud (from CaribSea) which supposedly contains iron, I did not expect to have to add iron, it certainly is
worth a try. I did have some 'Ulva' algea in the tank but the
pods just shredded it in no time (I am excited to see they
are reproducing, there is 'little ones' all over the place).

There also is another species of algea that came as a
straggler in the IPSF package, I think it is Tang Haven,
but is it not as red as their picture but a more of a green.
It seems to be growing, but not quickly either.


Thanks for the help

 

[piercho]

I've never been able to get Ulva to survive. I think it needs pretty enriched conditions. Red Gracilaria - tang heaven - only grows slowly for me.

I would think that an iron-enriched substrate would give you enough Fe in the tank. I've never tried it, so maybe I'm wrong. BillsReef uses both, I think. Search this forum for threads about Fe in which he has participated.