Re: [RML] Phytoplankton

Mach T. Fukada (fukada at hawaii.edu)
Tue, 17 Mar 1998 02:23:24 -1000

>The reason I suggested Ammonium Nitrate is that it is generally what's
>recommended for Aquaculture. 30-10-10 is a fertiliser blend of (N.P.K.)
>Nitrogen, Phosphate & Potassium. I don't know what Miracle Grow is but if it
>is one of those liquid fertilisers for home use I would be a bit concerned
>as it probably contains chelated copper or copper sulphate which could be
>detrimental for rotifer culture. Ammonium Nitrate will give you a very quick
>response. Other fertilisers will take time to break down into a form that
>the algae can consume. You could probably get smaller quantities of
>technical grade Ammonium Nitrate from a chemical or Hydroponic supplier. Of
>course it would be more expensive than the fertiliser grade. It really
>depends on the volume of green water that you want to culture. If you only
>have a small culture in most cases just old aquarium water works reasonably
>well. In Mach's case I guess he wants an ongoing culture or cultures
>particularly if a regular supply of rotifers are required. I don't know how
>rotifers will react with Phosphate levels.

Miracle Grow is 10-30-10 + minors. It has been used fairly extensively
here in Hawaii as a home use hydroponic solution for lettuce, onions, etc.
I didn't check to see if it has copper in forms that would be a problem to
the algae. However, we used it for lotus rhizome production without too
many problems (except green water). I have checked with the gurus here for
aquatic plants and they indicated that MG caused their water to turn green
really quickly. I suspect that it is a result of the high phosphate more
than anything else. As the saltwater rotifers go I suspect that a highly
active algae culture can remove most of the phosphate before it gets to the
rotifer culture tank (I need to test this out). But so far the rotifers
have been doubling in population everyday. I am looking foreward to seeing
about 14-16 rotifers per ml. Only problem is brine shrimp contamination,
alhtough I may be able to raise some of these buggers better now that the
green water is going. They way I figure is if I can get the rotifers to
reproduce well and in high numbers (1,000,000/l) maybe I can see about
raising empire gudgeons. I have been doing some reading on saltwater
species (gobies, groupers, mullet, etc) needs interms of small highly
nutritional food particles, it seems that BBS is not enough and greenwater
may not provide enough nutrition. Salt water rotifers are <.5 -.25 the
size of artermia napuli and can be enriched with HUFAs, VitC, etc and are
maybe about 40% protein. The freshwater rotifers should be similar in
terms of culture for mass rearing and can be up to 100-150 microns in size.
Perhaps a better food source for the many smaller rainbow /blue eye fry.
On a side note I have been oticing that fish raised outside in tubs
exposed to the sun lots of algae (micro and macro) tend to be more
colorful. Not sure if theya re getting more of the natural pigment
precursors from the things eating the algae or vitamin producting as a
result of being exposed to sun light (ala people and vitamin D)

MTF
Mach T. Fukada, Web Master
fukada at hawaii.edu
Honolulu Aquarium Society
http://www.geocities.com/Heartland/Meadows/2948/HASF.html