Silica/Silicates/Diatoms - Middle Tennessee Water

DanielJameS · Sep 17, 2018

Has anyone else in the Middle TN area had any issues with silica/silicates and ditaoms? Over the last 3-4 years I have struggled with on-going diatoms in my reef tanks and have to assume through process of elimination it's either the sand I've used or the water supply that are feeding it with silica/silicates.

I have a 4 stage BRS RO/DI with only one DI cartridge that is replaced fairly regularly, but knowing silicates will not register on a standard TDS meter I'm wondering if anyone has dug into the metro water supply and if the water is unusually high in silicates? Just asking as I don't have a silicate test kit and thinking of adding an additional DI cartridge, possibly with a silica buster insert.

I've also used "Oolite Aragonite Reef Sand" purchased from Petsmart (good deal when it was on sale) on both of my last two tanks. This stuff is extremely silty due to it's fine consistency but this last tank build, I rinsed the holy hell out of it multiple times and allowed it to dry for weeks before using it. I suspect that the sand may not be true "aragonite" and wouldn't be surprised to find it's high in silicates or mixed with some silica based sand. I notice the diatoms get crazy when I stir up the sand bed, but it's not due to nutrients because those have been under control, and this new sanded is not old enough to worry about being a nutrient sink.

Short of changing out the sand bed (not something I want to do in a 125) I also want to make sure I'm not feeding additional silicates into the tank via all of my top off and water change RO/DI water.

Thanks ya'll!

rcmike · Sep 17, 2018

I seriously doubt it is silica in your sand. I've used straight silica sand for years and never noticed any more diatoms than when I used aragonite or no sand at all.

Have you tested for silicates?

DanielJameS · Sep 17, 2018

rcmike said:
Have you tested for silicates?

No like I mentioned, I don’t have a test kit (though it’s now definitely on the list) I just wanted to check if anyone locally has had any issues as that would be a good indicator. I am going to end up upgrading my 4 stage RODI to a 6 stage anyway as thats a fairly cost effective upgrade for the amount of water I end up producing.

MikeyTN · Oct 2, 2018

I haven't had any issues with the metro water here. Franklin area however have very poor water. Not sure where your water source is coming from.

BigJohnny · Oct 2, 2018

DanielJameS said:
Has anyone else in the Middle TN area had any issues with silica/silicates and ditaoms? Over the last 3-4 years I have struggled with on-going diatoms in my reef tanks and have to assume through process of elimination it's either the sand I've used or the water supply that are feeding it with silica/silicates.

I have a 4 stage BRS RO/DI with only one DI cartridge that is replaced fairly regularly, but knowing silicates will not register on a standard TDS meter I'm wondering if anyone has dug into the metro water supply and if the water is unusually high in silicates? Just asking as I don't have a silicate test kit and thinking of adding an additional DI cartridge, possibly with a silica buster insert.

I've also used "Oolite Aragonite Reef Sand" purchased from Petsmart (good deal when it was on sale) on both of my last two tanks. This stuff is extremely silty due to it's fine consistency but this last tank build, I rinsed the holy hell out of it multiple times and allowed it to dry for weeks before using it. I suspect that the sand may not be true "aragonite" and wouldn't be surprised to find it's high in silicates or mixed with some silica based sand. I notice the diatoms get crazy when I stir up the sand bed, but it's not due to nutrients because those have been under control, and this new sanded is not old enough to worry about being a nutrient sink.

Short of changing out the sand bed (not something I want to do in a 125) I also want to make sure I'm not feeding additional silicates into the tank via all of my top off and water change RO/DI water.

Thanks ya'll!

Just fyi I consistently have high silica levels via ICP analysis and have zero diatoms. Have you confirmed you have high silica yet?

DanielJameS · Oct 2, 2018

BigJohnny said:
Just fyi I consistently have high silica levels via ICP analysis and have zero diatoms. Have you confirmed you have high silica yet?

No but I did discover a potential issue with my RODI unit even though I’m getting 0 TDS water, that number won’t necessarily reflect silica. I’m going to start there for sure as I’ve noticed diatoms are forming in my QT now so I’m thinking the top off is continually fueling the issue.

BigJohnny · Oct 3, 2018

DanielJameS said:
No but I did discover a potential issue with my RODI unit even though I’m getting 0 TDS water, that number won’t necessarily reflect silica. I’m going to start there for sure as I’ve noticed diatoms are forming in my QT now so I’m thinking the top off is continually fueling the issue.

What is the potential rodi issue? I'd recommend getting ati icp test (can order through Amazon). It tests your RODI and your tank water so you can see if you have elevated silica and where it's coming from. In my case it wasnt my rodi but I believe siporax in my displays sump. Again I don't have diatoms though so I'm not doing anything about it. What do you use for a rodi storage container and ATO container?

DanielJameS · Oct 3, 2018

BigJohnny said:
What is the potential rodi issue? I'd recommend getting ati icp test (can order through Amazon). It tests your RODI and your tank water so you can see if you have elevated silica and where it's coming from. In my case it wasnt my rodi but I believe siporax in my displays sump. Again I don't have diatoms though so I'm not doing anything about it. What do you use for a rodi storage container and ATO container?

1 is at the time I replaced my membrane, I was unaware I needed to replace the flow restrictor so I have a 100GPD membrane with the FR intended for a 75GPD membrane. It also appears the DI stage is not filling correctly but I’m not sure if there should be more flow there or not.

My RO storage is brute. ATO is a fairly typical 15gallon storage bin with a lid.