RODI Silicon Level

CMO · Jun 8, 2018

My RODI water shows all zeros in ATI ICP test except silicon is at 326 ug/l which they say indicates my resin should be renewed. However, my resin isn't that old and just starting to change color towards the bottom only. Is 326 ug/l really that high or can I run it a little longer? My DT level is about 130 ug/l using this water.

Thanks

Randy Holmes-Farley · Jun 8, 2018

You will frequently find silicate in ro/di water because it is one of the hardest things for an ro/ di to remove.

It is not necessary to have none. I dosed silicate. It is not to be feared unless you have bad ongoing diatom problems.

Do you have a Si reading in the tank?
Do you have a diatom problem?

CMO · Jun 8, 2018

Okay good. Si in my tank has been testing 100-130 ug/l. I wouldn't call my diatoms problematic but I do need to clean my glass pretty frequently, about every 3-4 days it gets covered pretty good.

Thanks

Randy Holmes-Farley · Jun 8, 2018

Here’s a copy and paste from my Triton testing article:

Silicon (Si). I dose silicate (as sodium silicate solution) to my aquarium. I boost the concentration to about 200 µg/L of silicon equivalent once a week or so. This water sample was drawn one week after the last dose of silicate. I know from previous studies that silicate is rapidly depleted in my tank, presumably by sponges (the reason I dose it), by diatoms, and possibly by the GFO that I use to bind phosphate.

Randy Holmes-Farley · Jun 8, 2018

FYI, my test showed 56 ug/L. My main point is that the amount coming from your ro/di for top off and water changes is less than I was dosing.

CMO · Jun 8, 2018

I didn't realized it was used up so quickly. That's helpful and sounds like I don't have much or anything to worry about. Thanks

Randy Holmes-Farley · Jun 9, 2018

You're welcome.

Happy Reefing.

Bmezz · Jul 26, 2018

I just got back my Triton test and Si is 378. So high right? And from your previous posts I have diatoms and algae on glass.
Could raise iodine at 53 and PO4 at .07038.

Love to get input!

coralbeauties · Nov 12, 2018

How is silicon removed? I have a lot of red slime on my sand bed and just got back my ati test and my ro/di water tests at 1540. I am guessing that is my red slime issue. Any help?
Jeff

Flippers4pups · Nov 12, 2018

jjoos99 said:
How is silicon removed? I have a lot of red slime on my sand bed and just got back my ati test and my ro/di water tests at 1540. I am guessing that is my red slime issue. Any help?
Jeff

In this thread, Randy explained that silicate was used up by his sponge populations. Not many hobbyist have a large number of sponges in their systems.

Local water companies use silicate to keep metal pipes from corroding. I think usually they dose them in the fall or winter. Not sure.

"Red slime" is a indicator of cyanobacteria, not diatoms.

saltyfilmfolks · Nov 12, 2018

jjoos99 said:
How is silicon removed? I have a lot of red slime on my sand bed and just got back my ati test and my ro/di water tests at 1540. I am guessing that is my red slime issue. Any help?
Jeff

With gfo.

But Diatoms and sponges and a few others use silicates not cyano.

CMO · Nov 12, 2018

jjoos99 said:
How is silicon removed? I have a lot of red slime on my sand bed and just got back my ati test and my ro/di water tests at 1540. I am guessing that is my red slime issue. Any help?
Jeff

That's pretty high and I'm not sure gfo alone will cut it. You should probably run multiple Di canisters and or load the bottom of one with anion resin followed by mixed bed di. If you can run multiple canisters with an entire single bed anion before the mixed bed di that should really do the trick. I don't have room for 2 canisters so I do both stages in one. Anion must go on the bottom

David Gaskins · Jan 30, 2019

Following up on this thread. Just got my ICP test back from ATI, and Ro/Di water had an elevated reading on Silicon at 1717 ug/l. I have a BRS 6 stage with Cation and Anion resin cartridges. Should I consider adding a stage with a mixed bed? Don't seem to be having any issues in tank other than some small areas of Cyanobacteria from time to time (elevated N03/low P04 that I am working on correcting). Only other thing I can mention is that I use a Brute 28 gallon for ATO storage, and auto-fill once a day for any ATO usage during past 24 hours. Could this storage arrangement be cause due to long term build-up? Should I consider draining and refilling once a month?

Thanks in advance for response.

Sincerely,

David

David Gaskins · Jan 30, 2019

Following up on this thread. Just got my ICP test back from ATI, and Ro/Di water had an elevated reading on Silicon at 1717 ug/l. I have a BRS 6 stage with Cation and Anion resin cartridges. Should I consider adding a stage with a mixed bed? Don't seem to be having any issues in tank other than some small areas of Cyanobacteria from time to time (elevated N03/low P04 that I am working on correcting). Only other thing I can mention is that I use a Brute 28 gallon for ATO storage, and auto-fill once a day for any ATO usage during past 24 hours. Could this storage arrangement be cause due to long term build-up? Should I consider draining and refilling once a month?

Thanks in advance for response.

Sincerely,

David

David Gaskins · Jan 30, 2019

Following up on this thread.

Just got my ICP test back from ATI, and Ro/Di water had an elevated reading on Silicon at 1717 ug/l.

I have a BRS 6 stage with Cation and Anion resin cartridges. Should I consider adding a stage with a mixed bed?

Don't seem to be having any issues in tank other than some small areas of Cyanobacteria from time to time (elevated N03/low P04 that I am working on correcting).

Only other thing I can mention is that I use a Brute 28 gallon for ATO storage, and auto-fill once a day for any ATO usage during past 24 hours. Could this storage arrangement be cause due to long term build-up? Should I consider draining and refilling once a month?

Thanks in advance for response.

Sincerely,

David