Best way to drop silicates

Hello

Im not positive why but after I moved my system to the new house the silicates have been off the charts My guess is because I had to use filtered water until I had the RODI setup but im not really sure. Ive done 3 35gal waterchanges and used a phosphate sponge but the silicates are still off the charts so if any one has any ideas they would be very much appreciated

Thanks Ricky

 

Most phosphate removers remove silicates afaik, if the phosphates are at 0. EG: phosphate sponge by Kent. Certan bacteria (or algae, i forget) can increase silicates...i think i read that somewhere. HTH!

 

GFO phosphate removers remove silicates. I don't know if the aluminum based ones do or not.

If you have any sponges in your tank, you will likely see them get bigger and reproduce. Additionally, you'll probably get some diatom algae that will absorb the silicates. Then you can remove the diatoms and the silicates will go with them.

 

So I have a good question then. I alwasy thought sponges are conisdered good because they do a great job filtering the water. Now the fact that they are growing is leading me to believe they are filtering too much and my water quality is not as good as I originally thought.

Can you confirm?

 

Not as much as you would think.

Some species of sponge build their skeleton out of silica and some build their skeleton out of Calcium carbonate. Our tanks, even if you have the biggest skimmer in the world, still contains plenty of Dissolved Organic Materials and particulate detritus. In other words, if you have naturally growing sponges that were hitchhikers, your water condition isn't necessarily poor.

With that said, don't go out and buy any decorative sponges. Non-photosynthetic sponges often don't get sufficient current in our tanks and they slowly starve. They are also typically bigger than hitchhikers and therefore require more food. I.e. you would have to be feeding plankton substitutes on a regular basis in addition to good current.

 

GFO's and and Activated Alumina (phosphate sponges) both remove silica and are very efficienet at it, more so than removing PO4, especially the activated alumina type. We have some small issues with the activated alumina type, as they release Aluminum which irritates some corals at times.

Sponges growing and doing well are the signs of a good tank not bad tank. Steve Tyrre wrote a book on sponges and ascidian and their abiltiy at filtering water

The Environmental Gradient
Crypitc Sponges and Sea Squirt Filtration Methods
Volum 1 of the Captive Manitenance
Advancted Techniques CMAT Series

Sponges, Phylum Porifera
Aquarium Invertebrates


Some things to read;

Aluminum and aluminum-based phosphate binders
Chemistry and the Aquarium

Iron Oxide Hydroxide (GFO) Phosphate Binders by Randy Holmes-Farley - Reefkeeping.com

Silica in a Reef Tank
Advanced Aquarist Feature Article

Phosphorus: Algae's Best Friend
Chemistry and the Aquarium

 

My blue sponge grew over the years and is spreading over some LR. Its good to know that my tank is in good health.

 

I own the book on sponges and tunicates by Steve Tyree. Good book by the way!
Anyway, sponges are beneficial to a saltwater tank as long as it isn't turning whitish in color(meaning it is dying). They remove nitrates from your water much in the same way that Tridacna clams do. They are filter feeders and will remove nutrients from the water column. Sponges, Feather Dusters etc. are very good for a tank, especially a reef tank.
Silicates will be removed by most phosphate material! Silicates, like phosphates and nitrates are beneficial in low levels for saltwater tanks and especially for reef tanks.

 

Might also make sure that anything-foods, etc.-you add to the tank are silicate free. I'm sure you mentioned that you tested your top-off water and it was OK. I went through this before using well water with silicates and it took about 6 months after starting RO/DI before the silicate were used up that bound to the rock and substrate.