[Coral-List] Use of Germanium Oxide to Control Diatom Growth

[TDWYATT at aol.com]

In a message dated 04/25/2005 8:32:51 AM Eastern Daylight Time, 
osp02a at bangor.ac.uk writes:

> I would be grateful to hear from anybody who has experience of
> using Germanium Dioxide for this purpose, or who can suggest another
> method for reducing diatom growth.

If this is a closed system, the rate-limiting nutrient for diatoms will be 
silicon/silicates for their tests.  Diatoms with tests formed during periods of 
low levels of silicates tend to rupture when they begin to photosynthesize 
during periods of light, and the tests will become a source for soluble 
silicates, so removal via skimming or mechanical filtration will limit cycling of the 
silicon and related hydrates.  When making the water change for artificial 
seawater and when topping off the system for evaporative replacements to maintain 
salinity, use only distilled water or Reverse Osmosis water that has been run 
through a deionizing column.  Once the diatoms have gone through their initial 
bloom, either removal with physical filtration from the water column or 
export via siphoning or foam fractionation (skimmer) will stop the problem.

HTH,

Tom

Tom Wyatt
tdwyatt at aol.com