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Discussion Starter · #1 ·
Sometime back in a thread on BBA the topic of dissolved silicon oxide came up. Some people correlate higher silicon dioxide levels with the appearance of BBA. I rather poo-poo'd the idea, having studied mineralogy and not having really come across the idea of silicon oxide (quartz) being soluble to any great extent. Tonight, I was doing some research on osmotic membranes when I came across GE's water resource article library. Therein lies an interesting article on silicon oxide with particular focus on how it interacts with reverse osmosis. I'll eat my hat now. Seems like it is far more soluble than I had thought.

Here is the link, in case it interests you. A Study of Silica and RO

The main article library is here. PDF files and handbooks.

This section is HTML about various aspects of reverse osmosis RO.

Andrew Cribb
 

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Would you prefer a cowboy hat or another style?
You need to show that BBA is caused by adding Silicates.

You need a basic tank doing well, add it and see.
I know silicates do not play a role, I have suggested this is the case with reef tanks as well on many occasions and recently I was in LA talking to many reef folks on this same topic.

CO2 low/variable=> BBA in about every cases I've ever seen.
You can do this over and over and over again.

Regards,
Tom Barr
 

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Is the solulability of silicon oxide dependant on pH? Could a higher pH (low CO2) situation allow higher levels of dissolved silicon oxide?
 

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Discussion Starter · #4 ·
I suspect you are right, it's PH dependent in some way. But not sure. In fact, silicon oxide ionized forms silicic acid which has some effect on PH in itself.

Tom, I still think it is unlikely. Your choice of hat. People do correlate silica with diatoms though. I can imagine why. Diatoms usually have silicate skeletons, do they not?

Andrew Cribb
 

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Sure, Si can limit diatom production, but where?
In our tanks? Are diatoms an issue?

Or perhaps out in the middle of pacific gyres where they are 2000 miles from any land based sources, 4km deep water witgh low upwelling, marine phytoplankton(versus epiphytic FW) diatoms can become Si limited or PO4 or NO3 limited depending on prevailing conditions.
I'll say that can occur and does occur there, not with FW reds.
A few horsetails and rushes and use Si.

How you apply the research and ideas is extremely important.
The amount of Si needed for diatoms is so small, rocks, gravel, fish etc provide plenty.

Reef folks run their systems much more clean than our as a rule.
They sometimes will get diatoms on their glass, so they tend to go after the Si using resins and special membranes. I'm not surwe it does much based on what I've seen, due to a large part from rocks, fish food etc in the tank already. I associate Diatoms with high PO4 in those systems. They do not have otto cats and the diatoms persist aftyer the first few weeks. The diatoms are different and have different strategies in SW.

Regards,
Tom Barr
 
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