Please help : Silicates and Diatoms

[Randy Holmes-Farley]

Yes I’ve read that, thank you. It doesn’t explain why Si would not be caught in the first cylinder, but caught in the second. If the ion is charged, it will be caught in that first stage by the Anion. If it’s not charged, it passes through, regardless of how many stages are in place. What would cause a lesser ionic bond that the Si ion passes through the first but not the second? What changes happen between the stages that helps make this correction? Does the Si gets “bumped out” by a stronger ionic bond, ie PO4? If so, how does that happen? And what gets priority if it’s not FCFS. That’s what I’m most curious about.

I’m not challenging the findings, just digging deeper for the complete answer. It’s how I learn.

Both remove a substantial fraction of what is present.

How about this as a random example: the first removes 80% of the silicate present. The second di removes 80% of the remainder, for a total removal of 96% of the silicate.

 

[BubblesandSqueak]

What test kit did you use? The only two samples you need to look at is the Rodi sample and a tank sample. Do them separately and post the results in a separate post. That way it’s easy to read and understand for readers.

when you start researching what a two stage Di resin you will realize that it just helps reduce the cost of Di resin, as you buy and use two types, Anion and Cation. Anion is responsible for silicates PO4 and NO3 filtration. So it depletes caster that the Cation, which filters calcium, copper iron etc… the Anion depletes faster, so a two stage lets you just replace that and keep the cation going longer, saving you money long term. Running 2 stages of the all in one Di resin doesn’t give you better protection, it will just last a little longer before changing out the AIO resin. If the Anion resin is charged, it’s not going to let Si sneak through. That’s why they make the colour changing, if it’s blue, it’s charged, and working. If it’s brown, it’s no longer charged and leaches back.

If I’m wrong, some one please let me know. I’m not a chemist .

Seachem test kit.
Hopefully this is easier to read.
My resin is half brown now after filtering ~50 gallons. (It was only about 1/4 when I put it away 2 weeks ago and I did back flush it) so should I order just one extra cylinder with resin or the upgrade kit which provides an extra filter and resin? The tap water I have does show silicates.

 

[BubblesandSqueak]

Both remove a substantial fraction of what is present.

How about this as a random example: the first removes 80% of the silicate present. The second di removes 80% of the remainder, for a total removal of 96% of the silicate.

Thoughts on if I should turn this 4 stage into a 6 stage or just one extra resin chamber? I posted a couple pictures and after sitting for 2 weeks, the resin looks half depleted. (I’ve only filtered about 50 gallons). I attached the town tests of the content they found. And the Seachem test is where I found that they said 10mg/L of silicate in seawater.

 

[Randy Holmes-Farley]

there are a couple of reasons why some ions are more poorly bound by di in general.

Part of it is because they may have an uncharged form (in this case, silicic acid). That form dies t bind and reduces the binding potential.

A second reason is that the binding is always a competition between binding hydroxide (the bound ion at full charge) and the ion of interest. Some just are more effective at displacing the hydroxide. The detailed reasons are heavy duty chemistry of hard and soft acids and bases, and how they interact with one another. I won’t go into that levels of detail here, but you can look it up elsewhere.

 

[Randy Holmes-Farley]

Thoughts on if I should turn this 4 stage into a 6 stage or just one extra resin chamber? I posted a couple pictures and after sitting for 2 weeks, the resin looks half depleted. (I’ve only filtered about 50 gallons). I attached the town tests of the content they found. And the Seachem test is where I found that they said 10mg/L of silicate in seawater.

The data you post doesn’t mention silicate, but many water companies add it to reduce pipe corrosion and release of lead.

I cannot judge the CO2 from that data, but CO2 often rapidly depletes di resins. So would an ro membrane with a hole in it.

For silicate alone, I’d just add a second di. Possibly a silica buster cartridge, though I’ve not seen data showing them to be better.

 

[Ziggy17]

Seachem test kit.
Hopefully this is easier to read.
My resin is half brown now after filtering ~50 gallons. (It was only about 1/4 when I put it away 2 weeks ago and I did back flush it) so should I order just one extra cylinder with resin or the upgrade kit which provides an extra filter and resin? The tap water I have does show silicates.

Based on these pics, your RODI is doing it’s job of getting the Si close to zero. Your tank water looks to have about 1ppm, so your rock or sand is still leeching some out. I’m not convinced your brown sand are silicates, until you look under a microscope, you won’t know.

 

[BubblesandSqueak]

quick update. turned the lights back on last night after the programmed light cycle should have been off and didn't realize AI Hydra 32 doesn't keep the time when turned off for a few days. so they came on full strength at 9pm and ticked off the inhabitant. Anyway, the sand looked pretty good and with the light on today, the brown hasn't exploded. Changed the socks and cleaned skimmer. Planning on doing the water change tomorrow to keep on track. If it happened again, I'll order the $100 microscope. Though I think I'd go for the digital one to plug into the phone to get an ID.

Ordering replacement resin and an extra canister. So just to be clear, setting up the extra canister it should go Sediment filter, carbo block filter, anion resin then the extra chamber blue mixed DI resin? (currently it's the 4 stage at Sed-Carbon-Blue Mix Di Resin).

 

[Ziggy17]

quick update. turned the lights back on last night after the programmed light cycle should have been off and didn't realize AI Hydra 32 doesn't keep the time when turned off for a few days. so they came on full strength at 9pm and ticked off the inhabitant. Anyway, the sand looked pretty good and with the light on today, the brown hasn't exploded. Changed the socks and cleaned skimmer. Planning on doing the water change tomorrow to keep on track. If it happened again, I'll order the $100 microscope. Though I think I'd go for the digital one to plug into the phone to get an ID.

Ordering replacement resin and an extra canister. So just to be clear, setting up the extra canister it should go Sediment filter, carbo block filter, anion resin then the extra chamber blue mixed DI resin? (currently it's the 4 stage at Sed-Carbon-Blue Mix Di Resin).

I think Randy is suggesting a second mixed bed Di if required. But your tests say your Di is scrubbing the Si just fine so, I guess that’s up to you.

Order ghe microscope now from Amazon. It takes a week to arrive. And if you don’t end up needing it, just send it back for a full refund including shipping. So no downside.