Sand, Silicates and Diatoms??????

[greenmaji]

Ive seen alot of discussion about sand and it seems that all of it that is used in FW is silicate based (as apposed to aggregate to prevent PH from rising).. but exess silicate should encourage diatom algae growth (diatoms are made predominately from silicate after all).. I was wondering if anyone that has been using this recently has had more diatom algae problems then they had with gravel (this assumes that you have used a substrate other then sand for FW)

 

[severum mama]

I've used both sand and gravel in my tanks, and I haven't noticed any difference in diatom growth. The only sand I've used is pool filter sand, so I can't comment on any other types.

 

[aqh88]

With my water being hard as well as high in silicates and phosphates it's very prone to brown algae. When I tried silicate sand in my 55g it was a real mess. I had columns of brown algae coming up out of the substrate and strings hanging off the caves. Have you ever seen a 6" column of algae? When I switched it to eco complete the brown algae was lessened to just a layer over everything. I get the same results with gravel in other tanks. Generally a few otos can keep it under control but when I use silicate sand they can't keep up. I wish I had a picture of that tank I only had 15watts of light on 55g and almost no fish yet but the tank was just filled with brown algae. I did get a few otos spawns though from the huge food souce.

 

[severum mama]

Gross! So I guess it depends on the water that you're using in combination with the other factors. Good point, I didn't even think about that.

 

[greenmaji]

Hay.. breeding ottos seems to be a great side effect!
It just seems to me that this might be worth mentioning when someone is looking to do sand.. If they are having moderate diatom problems then the sand might make it worse. maybe????

 

[Fishyfanatic]

I use pool filter and actually haven't had diatoms at all in the tanks. It's just that pesky green spot algae.

 

[m249saw]

Pool filter sand here too and no problems yet.

Plus it makes it easier for me with plants. Ive never been able to plant Glosso so easily.

 

[fearlessfisch]

I use quartz sandblasting sand from the hardware store (pure white). I had the normal new-tank diatom growth spurt, but i haven't had any problems with diatoms since. It is the darned green spot algae I am always fighting.

 

[aqh88]

In higher light I get alot of spot algae if the tank isn't planted well. It seems to outcompete the diatoms if there's over 1-2wpg on the tank. I think the silicate sand just sped up the diatoms growth rate. My horses' stock tank will get diatom columns but it takes nearly 6months of keeping it full of water for that to happen and there should be more nutrients in the stock tank due to dead bugs, horse slobber, and bits of grass.

No more diatom/spot algae water I'm getting the ro unit this month.

 

[Devilishturtles]

Ive seen alot of discussion about sand and it seems that all of it that is used in FW is silicate based (as apposed to aggregate to prevent PH from rising).. but exess silicate should encourage diatom algae growth (diatoms are made predominately from silicate after all).. I was wondering if anyone that has been using this recently has had more diatom algae problems then they had with gravel (this assumes that you have used a substrate other then sand for FW)

Silicate is what alot of sand is made out of, yes. The cell walls of diatoms are composed mostly of opaline silica. A slightly different form of the Silicon and Oxygen (and in silica, hydrogen also) used to make silicates, that I'm guessing doesn't effect the growth in water. There are many, many different forms of silicate, all involving different geometric/molecular structures of the same compounds.

Wow, you mean something I learned in school I can actually use?

 

[greenmaji]

So your guessing that the oxygen and hydrogen in your water will not have any effect on the sand to make it available to produce diatoms? Isnt erosion and sediment movement how bound up nutrients are released, water being the solvent?

 

[Devilishturtles]

I'm guessing that the molecular structures on the silicates (which is silicon and oxygen, and sometimes hydrogen combined) keep it from being released. The cell walls of diatoms are made of silica, and therfore maybe that is the reason they don't affect each other. Just a guess.