View Full Version : R/O membrane specific for Silica?

01/02/2010, 10:12 AM
I had our aquarium water tested with AWT and here is one of the results
Silica (Sio2-3)
Natural Seawater Value: 0.040 mg/L
Acceptable Range: 0.000 to 0.500 mg/L
Tested: 0.9 mg/L
(HIGH) Your silica level is too high. We recommend that you use a silica specific R/O
membrane in addition to deionization resin for your make-up/top-off water. You may also
use a commercially available phosphate absorber, as these will also remove some silicate.
Silicate is required by many types of sponges for growth/reproduction, but will also
encourage brown diatom algae growth. Any level above 0.3 mg/L may cause a diatom
bloom in the aquarium.

Do you carry a membrane specific for silicate?

01/03/2010, 10:41 PM
Their report is very misleading, Filmtec membranes have a 99% rejection rate for Silica and standard DI resin will take care of the rest. It is unknown where the silica reading they are getting is coming from but if you have a Filmtec membrane in your system your RO/DI water is not the source as long as you have a zero tds reading after DI.

Some people do back up their DI with a silica DI cartridge to give them peace of mind but I'm not sold. If you are seeing what you consider diatoms it is more then likely red slime from to high nutrient levels. Our GFO in a loose media reactor will reduce silica and phosphate levels and we highly recommend the Pellet or High Capacity.