Best media to reduce silicates from ceramic rock in FOWLR

holdyourlight

New member
I have a 125G that was set up about six months ago with about 80lbs of dry Cerameco Vidarock and dry Tropic Eden sand. I have had REALLY bad diatoms for going on 3 months now. I am positive it is diatoms. After doing some searching it seems that the Vidarock is notorious for leaching silicate for an extended period of time. I have never had silicate issues before the rock and my rodi is TDS 0 and has been tested for silicates in the past, so i know the rodi is not the source.

I have read that Phosguard might be better than GFO for removing silicates in particular. Just wondered if there are other/better options, or if Phosguard is the way to go.

Remember that this is a fish only, so i am not worried about harming corals.

Thanks!
 

bertoni

Premium Member
Any GFO should be fine and about as good as the PhosGuard. I'm not sure which, if either, would be cheaper.
 

holdyourlight

New member
Any GFO should be fine and about as good as the PhosGuard. I'm not sure which, if either, would be cheaper.

So Aluminum oxide is not any better at removing silicates than iron oxide? I've been running high capacity GFO for the past 2 months and it has not helped much :headwally:
 

bertoni

Premium Member
I don't think so. You could give it a shot, but either should remove silicate. Have you run a silicate test?
 

hart24601

New member
I did not have that issue when using vidarock, used new rock twice now FWIW. I would also suspect the sand. Any other additions?
 

holdyourlight

New member
I did not have that issue when using vidarock, used new rock twice now FWIW. I would also suspect the sand. Any other additions?

No other additions. Only fish.
There have been several other accounts of this with the vidarock. Guess i got unlucky.

After 2 months GFO would be ineffective for PO4. Would that be the same for silicates?

I didn't mean that i used one batch for the entire 2 months. I usually replace it after 4 weeks
 

dkeller_nc

New member
Keep in mind that because one of the common major components of many ceramic formulations is alumina silicate, it might take an exceedingly long time to substantially deplete the first few microns of the surface of the rock of silica.

In fact, certain types of ceramics are entirely composed of alumina-silicate, so dimunition of the dissolution of the silica/aluminum in saltwater may depend on coating of the surface with inert material (such as precipitated calcium carbonate) or organics.

In other words, you might not be able to control the "leaching" of silica into the aquarium water until the rock gets almost completely encrusted with coralline algae.
 

holdyourlight

New member
Keep in mind that because one of the common major components of many ceramic formulations is alumina silicate, it might take an exceedingly long time to substantially deplete the first few microns of the surface of the rock of silica.

In fact, certain types of ceramics are entirely composed of alumina-silicate, so dimunition of the dissolution of the silica/aluminum in saltwater may depend on coating of the surface with inert material (such as precipitated calcium carbonate) or organics.

In other words, you might not be able to control the "leaching" of silica into the aquarium water until the rock gets almost completely encrusted with coralline algae.

This is quite interesting, thanks for the response. Since this is a FOWLR i have not paid any attention to Cal, Alk and Mag levels and i don't plan to ever seed the vidarock with live rock as i do not want any unwanted pests in the tank, so getting coralline to grow on this rock may be just about impossible in the interim. Although on my last tank that i set up in the same manner with BRS eco rock the rocks did fully encrust with coralline after about 2 years. Man that would be a long time to be looking at a tank full of diatoms!

Any other options? You say coralline "or organics" would vinegar dosing do the trick or are you talking about something different?

Thanks!
 

dkeller_nc

New member
Essentially, I'm referring to a slime layer of dead bacteria, absorbed lipids/fatty acids, etc... Organic layers on solid surfaces can take quite a few forms depending on the environment. Whether or not that would reduce dissolution of the surface ion layers to a level that wouldn't promote diatom growth is highly speculative.

In fact, whether or not silica concentrations in a typical reef tank can be reduced to the point of becoming the limiting nutrient for diatom growth is also speculative.
 

holdyourlight

New member
Essentially, I'm referring to a slime layer of dead bacteria, absorbed lipids/fatty acids, etc... Organic layers on solid surfaces can take quite a few forms depending on the environment. Whether or not that would reduce dissolution of the surface ion layers to a level that wouldn't promote diatom growth is highly speculative.

In fact, whether or not silica concentrations in a typical reef tank can be reduced to the point of becoming the limiting nutrient for diatom growth is also speculative.

I follow this, but not completely. what would you do if you were in my shoes?

I spent a lot of time and money to have these rocks custom made and this is especially frustrating considering their website says this:

VidaRock is inert and is like putting a piece of glass in your tank. If it is clean, it will not affect water chemistry at all.
 

jimrawr

New member
I used VidaRock in my 75g exclusively, and never had any diatom issues from the rock. I dont think its the ceramic TBH, unless they have changed their processes of making. I starting my tank 2014 May
 

bertoni

Premium Member
The Salifert silicate test might be okay. I think it worked well enough for me, but it's been a long time since I was dosing silicate.
 

victorvie

New member
I had the same issue and started running phosguard and GFO at the same time. I know it sounds kind of crazy but it did help eliminating the issue for me. I now run Biopellets and everything is running stable.
 

holdyourlight

New member
http://www.reefcentral.com/forums/showthread.php?t=1766792

Did you try Poly-filter by Poly-Bio-Marine? It was reported that it absorbs silicates. I don't know if that's a fact.

I didn't see anything mentioning the poly-filter in that thread?
I did read this on that companys website though:
"These various silicates all produce diatom growth in reef tanks.
Poly-Filter does not sorb these dissolved noncharged forms of silicate."


I used VidaRock in my 75g exclusively, and never had any diatom issues from the rock. I dont think its the ceramic TBH, unless they have changed their processes of making. I starting my tank 2014 May

Thanks for the response. That's interesting. I did read several other places where people were convinced it was vidarock causing long diatom blooms. It my case it has to be either the rock or sand. There is nothing else in the tank.

The Salifert silicate test might be okay. I think it worked well enough for me, but it's been a long time since I was dosing silicate.

I need to do some more reading on silicate test kits. Still wondering how useful one would be for me.

I had the same issue and started running phosguard and GFO at the same time. I know it sounds kind of crazy but it did help eliminating the issue for me. I now run Biopellets and everything is running stable.

Interesting. I am going to start running some phosgaurd as well, because, why not...

Here is the tank in November 2014 (3 months since starting tank)
1029141956_zpsb05862c2.jpg


And now (6 months since starting tank):
0203152000_zpse0e6fb55.jpg


The only reason the glass and sand aren't covered are 1. magfloat and 2. diamond goby
 

bertoni

Premium Member
If they are diatoms, then a lot of snails should eat them. Any of the Trochus or similar genera would count, I think.
 

holdyourlight

New member
If they are diatoms, then a lot of snails should eat them. Any of the Trochus or similar genera would count, I think.

That's a great idea. They are for sure diatoms. I have a Kole tang in QT right now and i put a small piece of PVC from the display into his tank and he gobbled them up. I think the Kole will help a bit, they are natural diatom eaters.

I think snails would help even more, but i am paranoid about anything hitchhiking on snail shells (ich, algae), and not sure of a good method to quarantine them
 

ReefsandGeeks

New member
Snail shells, particuarly turbos IMO, are a good way to introduce corralline into a tank without LR. IT's usualy growing on their shells. That would eventualy cover up the surface of the structure, blocking leaching. Would take quite some timethough, and 100% coverage isn't likely IMO. You could always scrub their shells free of algae, but it seems you're already having problems with algea, so not sure what the point would be.

As far as Phosguard, I tried it in my mixed reef and within a few days diatoms were dramaticaly reduced. Not sure if it was due to phosphates or silicates, as I hadn't tested, but it did work for whatever situation I had. Only problem I had with it was some of my soft coral closing up after a couple days. Fish showed no ill effects what so ever, so I's suspect you'd be okay with it. It is fairly cheap compaired to GFO which is why I tried it in the first place. Seems as though it may be more aggressive than GFO at absorbing phosphates, and phosphate drop was too sudden for my soft coral (or it leached aluminum? debatable). Might be better at absorbing silicate too. Not sure if there is a reliable/accurate silicate test kit. I've never bothered to think about it.

BTW, I love the zoas in your profile pic, holdyourlight. Wish I had some of those.
 
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