THE NEVER ENDING DIATOM BATTLE!

[Flippers4pups]

I've been battling diatoms for several years now. Yes, it's diatoms and nothing else. It hasn't effected any corals and isn't present on glass or rock. Tank was started in 2015.

Sand bed is the most effected. Last year I replaced my sand bed with new Caribsea aragonite special grade thinking the sand I started with was contaminated possibly with silicate. This sand replacement had no effect on the diatom problem. Sand bed has been vacuumed at times with no effect on the diatoms. Stays consistent.

Source water is from a 6 stage RO/DI unit. Membrane is about three years old. I replace all filters every 6 months. Unit has two mix bed DI resin chambers. TDS is always 0.

Possible sources of silicate/silicon contamination are from the following:

Source water

Calcium hydroxide (Kalkwasser)

Rock (dry rock)

Those are my theories behind the source as Ive not tested my source water or my ATO reservoir water.

Observations:

I do a weekly water change of 10 gallons. After the water change the diatoms increase and decrease a little at the end of the week.

If I go two weeks without a water change, they subside more, but are still present.

Lights out for four days diminishes them a little, but return.

ATO reservoir top off is every week of ten gallons

All of this leads me to believe there's a elevated of silicate/silicon in the water coming into the system.

Ideas or personal experience in combating and overcoming this issue is much appreciated from the community!

 

[brandon429]

Cheat with uv

 

[Flippers4pups]

Cheat with uv

UV unit has been on the system since 2016.

 

[Sallstrom]

I answered in the other thread. Should I move it here? If the other one were more to chemistry.

 

[Miller535]

Have you considered a ICP test? I prefer Triton, byt ATI test your RODI water for free, including SI.

 

[Miller535]

For example (and I have been battling some diatoms too), this was my Si, tested by Triton.

 

[Copingwithpods]

This is interesting as you have ruled out your tank as the source already in that your rock, sand, tank and everything in it isn't the source as it is only made worse through water changes. That still leaves many suspects such as your mixing containers, salt mix, tubing for incoming water and your water source.

 

[Sallstrom]

Since we’ve sending water samples to Triton lab since 2014, I know what levels we’ve had in our tanks at work. Some 10x the recommended value, most times just slightly above. I haven’t seen any difference in diatoms though. So I don’t believe that’s the cause.

I do believe diatoms are great opportunists and they are often the first organisms to start establishing on new and clean surfaces. So in your case, the sand grains are clean and gets light on them. Diatoms start to grow. You clean the sand, new clean sand grains get light on them, new diatoms.

I guess you need a really good sand cleaning crew if you want a white sand bed in a tank with lights enough for corals. Perhaps it could work with sea cucumbers and sand shifting sea stars. Or a fish filtering the sand.

Or wait until coralline algae covering the sand grains and outcompetes the diatoms.

Just some ideas and guesses

 

[Miller535]

Since we’ve sending water samples to Triton lab since 2014, I know what levels we’ve had in our tanks at work. Some 10x the recommended value, most times just slightly above. I haven’t seen any difference in diatoms though. So I don’t believe that’s the cause.

I do believe diatoms are great opportunists and they are often the first organisms to start establishing on new and clean surfaces. So in your case, the sand grains are clean and gets light on them. Diatoms start to grow. You clean the sand, new clean sand grains get light on them, new diatoms.

I guess you need a really good sand cleaning crew if you want a white sand bed in a tank with lights enough for corals. Perhaps it could work with sea cucumbers and sand shifting sea stars. Or a fish filtering the sand.

Or wait until coralline algae covering the sand grains and outcompetes the diatoms.

Just some ideas and guesses

What kind of levels have you seen that were high without problems? Could be helpful to rule things out.

 

[Flippers4pups]

This is interesting as you have ruled out your tank as the source already in that your rock, sand, tank and everything in it isn't the source as it is only made worse through water changes. That still leaves many suspects such as your mixing containers, salt mix, tubing for incoming water and your water source.

From my research, the containers are okay.

The salt mix is the same as I've always used for decades, IO. Tanks in the past using it never had issues with diatoms. New house back in 2012 with a different water company.

For example (and I have been battling some diatoms too), this was my Si, tested by Triton.

Did you ever eliminate the source? Did you find where it came from?

 

[Miller535]

Well, I know it was not coming from my water. As I had plain RODI water tested, and also had water tested that was fresh mixed saltwater in my brute. Plain RODI came back zero, and fresh saltwater came back normal. I assume it has to be food, but I can not prove that. While I am not recommending it, I used GFO and my SI went from 10x too high that test, to normal 6 weeks later when I re-tested. GFO is very good at removing SI

 

[Sallstrom]

What kind of levels have you seen that were high without problems? Could be helpful to rule things out.

We had around 800 in one tank and over 1000 ug/l in another I think. I can check tomorrow for more exact numbers.

In both tanks we used silica sand as filter media in sand pressure filters, and turned them off by accident. My guess is that something happened in the filters when the flow stopped for a couple of hours, which released Si from the sand(low oxygen level->low pH perhaps). We didn’t see elevated numbers when the filters ran properly.
Sorry for the side story..

 

[Flippers4pups]

Well, I know it was not coming from my water. As I had plain RODI water tested, and also had water tested that was fresh mixed saltwater in my brute. Plain RODI came back zero, and fresh saltwater came back normal. I assume it has to be food, but I can not prove that. While I am not recommending it, I used GFO and my SI went from 10x too high that test, to normal 6 weeks later when I re-tested. GFO is very good at removing SI

I can do that with a reactor on the system, but really want to keep my P04 up and not 0.

What test kit did you use for SI? Or did you ICP test it?

 

[Miller535]

I can do that with a reactor on the system, but really want to keep my P04 up and not 0.

What test kit did you use for SI?

I didn't use a kit. I had ICP testing done.

 

[Flippers4pups]

My municipal Water report doesn't list any silica or silicon. Doesn't mean it's not there.

I could rule out source water with a Hannah checker, but I'm leaning towards taking out a mixed bed and replacing it with anion resin to remove any chance of silicate/silicon. Yes I would need a test kit to verify at some point.

In the mean time I could sock some GFO and place it in the fresh water side of my mixing station.

 

[Miller535]

I mean no disrespect by this, but are you thinking that it's diatoms and no Dino's just because it's on the glass only? Or did you confirm this with a microscope?

 

[Flippers4pups]

I mean no disrespect by this, but are you thinking that it's diatoms and no Dino's just because it's on the glass only? Or did you confirm this with a microscope?

Microscope. No disrespect taken.

 

[Miller535]

While I know that many people have "beat" diatoms. I would think that there are many kinds, just like any other nuisance algae. And that each one would need to be treated differently.

I am currently working on Dino's, and diatoms. I bought a few 10 micron socks that seem to have helped. When I do my water changes I vacuum my sand heavily, purposely stirring it up, then I put that 10 micron filter sock in for about a day. Kind of like the old diatom filters that people use to use.

 

[Flippers4pups]

While I know that many people have "beat" diatoms. I would think that there are many kinds, just like any other nuisance algae. And that each one would need to be treated differently.

I am currently working on Dino's, and diatoms. I bought a few 10 micron socks that seem to have helped. When I do my water changes I vacuum my sand heavily, purposely stirring it up, then I put that 10 micron filter sock in for about a day. Kind of like the old diatom filters that people use to use.

I have used Chemiclean a while back before the microscope confirmation and it didn't touch this.

Currently with lights just coming on:

Drives me nuts! Lol

 

[Copingwithpods]

By any chance do you know if your house plumbing is copper or pex? I remember an article a while back about pex leaching over 150 different chemicals or something along those lines.