# Sand leeching silicates - soaking sand?



## edacsac (Nov 13, 2006)

I have a non-planted section of sand in my tank, that gets removed over time due to cleaning and water changes that I replace. I've read plenty of threads talking about sand leeching silicates and causing algae, and I believe I've even experienced it myself. 

Does it seem reasonable to soak new sand in water and change the water say daily over a short period to remove some of the silicates, sort of like preparing sand? I haven't replaced sand lately since I don't want to induce any more algae.


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## lemonlime (Sep 24, 2006)

Silicon is present is all water and leeches extremely slowly from various types of minerals. Glass is also largely silica. Silicon is to rocks as Carbon is to life, silica is one of the most abundant elements on earth. Changing the water isn't going to reduce the silicic acid as your tap water is the main source. I was reaserching this once and found some diatoms are actually capable of pulling silica from glass itself! interesting 

How long has your tank been running? The diatoms (brownish yellow algae) have a sort of boom or bust mentality and don't compete well in a mature aquariums. Otos and other algae eaters relish these diatoms and once they devour them they usually never return. I actually like diatoms, nothing like a thick carpet of yummy diatoms to say welcome home and help establish one of the planted tanks best finned friends the Oto!:biggrin:


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## edacsac (Nov 13, 2006)

My tank is about 6 months old right now. It's only a 10 gallon, with two puffers and red shrimp. I've been through most algaes and I'm pretty clean at this point.


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## mistergreen (Dec 9, 2006)

try reducing phosphate & light & increasing CO2. 
like lemon lime said, Silica is everywhere and it isn't necessarily linked to a diatom bloom. Diatoms use the silicates to build their covering however.


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## edacsac (Nov 13, 2006)

I thought I would post an update based on experience here. I had a sandy area in my tank that I let run dry, by removing a bit of sand each water change and not replacing it. Well, tank has been looking great except for some BGA that I clean regularily. All other algae was gone for several weeks. Tank was stable and better off than it has ever been. Just replaced my sand bed on 8/4 and today (8/8) I have hair algae on 75% of my plants. I guess the proof is in the pudding.


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## CampCreekTexas (Feb 28, 2007)

EDIT ~ just reread your last post and you didn't remove the old at the same time as you added the new, right? So the following doesn't really apply after all. Hmmm... 
>>>>>>>>>>>>>>>>>
Just thinking out loud here with no real experience... Instead of silicates, there could be two other causes. One ~ when you removed the sand, you removed a lot of beneficial bacteria. That could cause an algae bloom until the new sand is colonized with bacteria again, akin to what happens in a new tank though on a smaller scale maybe. And two ~ when you removed the old sand, you stirred up the mulm and other detritus that had been caught below it, loosing it and extra nutrients into the water. Couple that with the drop in beneficial bacteria and seems like algae would pop up.


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## edacsac (Nov 13, 2006)

I'm on to what your thinking, but I didn't swap out sand. When I do water changes I remove a little bit of sand off the top that is coated with algae with the water change hose. Eventually I'd replace it, but recently I just kept removing without adding new until I was left with bear glass in the sand area. I left it like this for a couple oif months. I just added a fresh layer of sand this past weekend after not having any for two months.

Sorry I wasn't more clear, and thinks for your reply!


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## mistergreen (Dec 9, 2006)

so you just added new silicates?

sand is pretty much silicates.


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## lemonlime (Sep 24, 2006)

On topic, off OP noodling.

I recently setup a new aquarium using ADA aquasoil. I'm guessing my local tap water is pretty high in silicates as I've always had a huge bloom of diatoms when starting a tank. Silicon is most present in water around volcanic activity, this is the kind of conditions it takes to really unleash silicon into water, extremely high pressure and heat.

Anyhow, setting up this new aquarium, to my surprise I've yet to see any diatom. Not using any sand by the way. The tank is still fairly new so perhaps the tank hasn't reached proper levels of nutrients to be favorable for diatoms.

I do not think absence sand leeching silicon is the reason though. Silicon leeching from say quartz is so slow. Tap water is the source, flowing down rivers picking up water from springs, seeping from river bed et cetera.

Look at MSDS sheets for Silicon, it states that: Solubility in H2O: insoluble
Now water is the ultimate solvent, and anything can be dissolved in it to some extent.

Diatom are rather unique among algae that their out wall is comprised of mostly silicon. Other algae use calcium, phosphates, proteins and so on and silica is not important.


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## CampCreekTexas (Feb 28, 2007)

edacsac said:


> I'm on to what your thinking, but I didn't swap out sand. ... Sorry I wasn't more clear, and thinks for your reply!


Gotcha' now! I didn't notice that 'til I reread. NP and YW.  (Interesting subject by the way.)


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## plantbrain (Dec 15, 2003)

I've added orthosilicic acid to tanks, never found any relationship.

Limiting it never really has much use nor excess levels because, well....most all tap water has lots. Yet those folks do not have diatom blooms.
........So.................

New tanks, ADA soils etc, need frequent water changes, 2-3x a week 50% to prevent algae for the first 1-2 months, then reduced down to once a week 50% thereafter.

ADA clearly states this, as do most folks when starting a new tank.
Then it's not an issue.

Regards, 
Tom Barr


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## edacsac (Nov 13, 2006)

I'm guessing that adding orthosilicic acid resembles sand leeching in a controlled manner of some sort, and what I'm seeing is coincidently related to the sand?


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## plantbrain (Dec 15, 2003)

Nope, not due to the sand.
Might be something else on/in the sand perhaps, bit not the silicon.

When you disturb sediments, you pull up lots of things, that can induce algae by itself.

No sand needed.
ADA sediments also tend to induce diatoms since they are able to handle to lower pH's and grow well with the nutrients that are leeched.

You can mitigate that via Zeolite, water changes, lots of plant biomass and healthy plant growth, algae eaters, etc.

Then you have far fewer issues.

What type of music you play?

Regards, 
Tom Barr


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## bgoodwins (May 3, 2007)

Tbarr is correct. The silica in sand is incredibly insoluble.


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## edacsac (Nov 13, 2006)

...then I guess I've come up with a better reason why I have new algae. I've added 1/3 of the overall tanks plant mass in new plants (some super fast growing), they have been growing like mad the past week, but I didn't up the co2 level! Damnit!

I am not looking forward to changing the co2 level. It took me probably 12 hours over almost two weeks to get it dialed in the first time...



> What type of music you play?


I play my own music right now. It's influenced alot from heavy metal/speed metal/punk rock, along with specific jazz and classical feelings. Everything I play gets tainted with speed and agression. Myself and another fella have been writing and recording for several months now, working toward an album. Although it's based on metal, it has some very nice jazz and classical based chord progressions, with epic sounding choruses!


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## plantbrain (Dec 15, 2003)

Yea, I have the same issue with music, but it gets funkified and you cain't wash it off.

I just do not have the time to devote to a band or recording at least for another year. 

Fast growing weeds will hog all the CO2.
If you only have "just enough" CO2 before, and you add fast growing weeds and increase the growth demand/rate by 1.5X or 3x etc, then what happens to the CO2?

It's the first and fastest to go(always!).

I have some Myriophyllum in a tank with some Lobelia. The tank had just enough and after adding the Myrios, the Lobelias never did well.
I played around for months with that one.
It was the CO2.

I could rule out nutrients etc, I had little algae, but the plants where not flourishing. I've seen and had worse bouts where algae did creep in and I looked and the CO2 was off a little. 

I added a bit more, kept things well pruned with the faster growers, went after the algae and about 1-4 weeks later depending, I had things back the way they should be.

Then less work effort etc..........

It's rather obvious, but more plants= more uptake, less current(harder to get the CO2 to the plants) and lower O2 during the night(less circulation and mixing from above).

But............folks often do not think or consider these things.
But it's still a CO2 issue in most cases, it's just as far as plant health/fish health, the other factors do play a role and folks do not give them consideration.

I like good current, so do fish, adds O2(especially at night), sure, degasses some CO2(easy to turn the valve 1/8-1/4turn though), but at least the CO2 that's there is getting to the plants.

Regards, 
Tom Barr


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