My Slice of the Microscopic World

[SubzeroLT]

Starting a new thread journeying into the microscopic world of our reef tanks. Not all images are mine. But will also include filter/coral/wool samples that cross my path.

Hopefully this thread will be a useful reference to shed light on issues we see in our tanks such as algae or even fish parasite issues. And to encourage discussion about the right treatment once we identify what it is under the microscope.

To the naked eye, diatoms look similar to dinoflagellates but are actually very different under the microscope. The treatment path is also different. Applying the wrong fix will only results in prolonging the issue or even create new issues.

 

 

[SubzeroLT]

A couple more pics of diatoms

They are in fact beneficial and always present in a balanced tank system. According to Wikipedia, diatoms in the ocean generate 20% of the oxygen produced on the planet each year. 

 

Diatoms are a form of photosynthetic single cell phytoplankton. While some reefers hate it, here are some fun facts on diatoms

 

• Diatoms take up silicic acid from the water to form a silica shell (a form of glass). Sources of silicon : silica sand/quartz sand (from the beach), tap water, marine salt mix
• Diatom chloroplasts (i.e. plant cell organelles that convert light energy into chemical energy via the photosynthetic process) are yellowish brown due to the presence of photosynthetic pigments such as chlorophyll (green), beta carotene (orange), and fucoxanthin (orange)
• Cell walls made of silica (glass). Their exoskeleton are made of 2 halves that fit inside one another perfectly.
• The walls are called frustules and have 2 main shapes – longish shape (called Pennate) and disc/cylindrical shape called centric)
• Diatoms are beneficial – they can outcompete the growth of other types of algae. And prevent HAB (Harmful Algae Bloom) – green water, cyanobacteria bloom, dinoflagellates
• Copepods eat phytoplankton (including diatoms) which in turn feed the fish

 

Note that once silicates are depleted, other forms of algae can appear. Hence a good balance is required.

Silica are in fact critical for the reef aquarium. Normal levels are 0.02ppm - 2.9ppm. Marine organisms that use silica :

• Marine sponges (beneficial filter feeder) incorporate silicates in their structure.
• Some mollusks (snails) have radula (teeth) to scrape off algae from rocks/glass. These teeth contain substantial silica.
• And of course, diatoms - benefits mentioned above.

Credit : Pic from https://socratic.org/

 

In any case, if diatoms are a bother, especially when silica levels are elevated beyond the normal levels mentioned earlier, consider the following :

• 'Export' the silicates by siphoning out the diatoms when they form. Don't just stir or turkey baster it off the rocks/sand bed
• Use aragonite sand instead of quartz/silica sand
• Avoid using tap water. ICP test of tap water at Bt Batok has 1.12ppm of silicon. Use a good RODI filter to prepare water for water change & top up
• Use resins such as Rowaphos (and probably other similar products). These remove plenty of phosphates but also some level of silicates.

[JiaEn]

Great info!  

Diatoms are often mis-accused by reefers. 

36 minutes ago, SubzeroLT said:

Diatoms are beneficial – they can outcompete the growth of other types of algae. And prevent HAB (Harmful Algae Bloom) – green water, cyanobacteria bloom, dinoflagellates

Totally agree.  Having diatom as dominant algae in the aquarium is actually a good defense against more detrimental species. 

36 minutes ago, SubzeroLT said:

Copepods eat phytoplankton

Not to mention many corals prey on these planktons too. 

Diatoms are also an effective means of phosphate export. 

39 minutes ago, SubzeroLT said:

'Export' the silicates by siphoning out the diatoms when they form. Don't just stir or turkey baster it off the rocks/sand bed

This is where we are different. I would blast the sand so that more corals can feed on these tasty stuff.  Also,  at the same time, maintain diatom dominance in the aquarium. 

[Guest]

Will microscope able to see nitrifying bacteria?

[SubzeroLT]

On 5/3/2021 at 5:21 PM, Willy Guccivera Yap said:

Will microscope able to see nitrifying bacteria?

Let me try

[Sherilyn91]

Nice sharing! Thanks Leon for the information.. following to know more..


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