How long after dosing silicates is phophate testing reliable ?

[Reef Puncher]

Please stop misinforming people with silicate and Hanna checkers.

Phosphate testing with the hanna checkers WILL be accurate as long as you maintain less than 2ppm silicate.

Idech, you made massive doses of silica (probably over 30ppm if I remember correctly?)

Diatoms will almost always rapidly deplete silicate. You can safely dose 1-2ppm a week for diatoms and still use the hanna checker.

hmm. so if i had over 2ppm it could theoretically throw it off. interesting. suppose i would have to buy a silicate test kit to know. i know for a while i was definitely dosing more than 2ppm as i wasnt getting the diatom bloom. i stopped dosing altogether. just not sure if i can trust the hannah or not yet and without knowing the silicate levels, i suppose i wont know.
i guess i could just test multiple phos kits to the hannah, compare, and when they start matching i know im good.

 

[Reef Puncher]

I’m sorry you view it that way but it’s not misinformation. I’m not the only one saying it, if I were, I would ‘t. You can regularly see people on FB reefing groups talking about it.

The fact of the matter is, since it’s not harmful for the reef, most people don’t test for silicate, so they have no way of knowing if they are above 2 ppm or not. And the Hannah checker gives them impossible readings.

I did dose a lot of silicate one time, a whole lot. The last time, I didn’t dose as much and still got funny results. I might have been over 2 ppm, I don’t know.

So next time I talk about, I’ll mention that 2 ppm limit. That’s all.

yea thats kind of the position im in. i dont test silicates. no clue what my levels are. hmm.

 

[Miami Reef]

most people don’t test for silicate, so they have no way of knowing if they are above 2 ppm or not.

They don’t need to test for it. We can use math to determine how much silicate to add.

yea thats kind of the position im in. i dont test silicates. no clue what my levels are. hmm.

Stop dosing until the diatoms on the glass turn into green algae. Then resume.

 

[Idech]

They don’t need to test for it. We can use math to determine how much silicate to add.


Stop dosing until the diatoms on the glass turn into green algae. Then resume.

I never had any diatoms anywhere, or very little. Let alone on the glass. It’s not so easy to determine when you should stop.

 

[TWYOUNG]

I’m sorry you view it that way but it’s not misinformation. I’m not the only one saying it, if I were, I would ‘t. You can regularly see people on FB reefing groups talking about it.

The fact of the matter is, since it’s not harmful for the reef, most people don’t test for silicate, so they have no way of knowing if they are above 2 ppm or not. And the Hannah checker gives them impossible readings.

I did dose a lot of silicate one time, a whole lot. The last time, I didn’t dose as much and still got funny results. I might have been over 2 ppm, I don’t know.

So next time I talk about, I’ll mention that 2 ppm limit. That’s all.

My personal experience has been the Hanna LR model is not affected by silica like the ULR and phosphorous models are.

 

[Idech]

My personal experience has been the Hanna LR model is not affected by silica like the ULR and phosphorous models are.

That is what I have read from other people’s experience, also.

 

[Randy Holmes-Farley Verified Community Expert]

Is there any unanswered issue that someone still wants addressed in this thread?

 

[Idech]

Is there any unanswered issue that someone still wants addressed in this thread?

Not for me.

 

[Reef Puncher]

Is there any unanswered issue that someone still wants addressed in this thread?

i have an unrelated question. i gave up on silicate dosing after trying for several months. it did produce diatoms, but they didnt outcompete the dinos. Still had lots of dinos. im too impatient to wait out another month or two, so i finally gave in after a 5 month battle and started dosing Dino X last week. It appears to be slowly working.
Your a chemist so i figured you would be the best to ask and if even just answer one of the following questions, that would be great.

What interaction does Dino X ingredient, methylmethanamine have on dinoflagellates? How does it kill them? Do you know the principal action of what that chemical does in this application or in any other uses? it is strictly only used for this purpose of algaecide?

I cant find any info online on if it
A. starves them out
B. Stops their reproduction
C. Destroys their armor
D. Destroys their ability to photosynthesis
E. flat out kills them some other means

 

[Randy Holmes-Farley Verified Community Expert]

The compound in Dino X is not what you posted.

The compound you mention is a segment of a polymer.

That polymer is not unlike other cationic antimicrobial polymers such as the actual ingredient in Vibrant and Algaefix.

They work by damaging cell membranes.

I have no idea what other membranes it will damage, but I highly doubt it is specific to dinoflagellates.

 

[Reef-Engineer]

I think that the question was not fully addressed. Someone posted anecdotal evidence that silica dosing impacts hanna ulr checker test results. Another person said, no that is wrong. And that was pretty much it.

I can tell you for sure that it does impact hanna ulr test results same day. I am not sure for how many days after, but my phosphate didnt just go from 0.03 to .19ppm overnight. i dosed 3g of 40% water glass into 330g this morning.

So i think, though anecdotal, we have to acknowledge that there is an impact here.

Thoughts?

 

[Miami Reef]

I think that the question was not fully addressed. Someone posted anecdotal evidence that silica dosing impacts hanna ulr checker test results. Another person said, no that is wrong. And that was pretty much it.

I can tell you for sure that it does impact hanna ulr test results same day. I am not sure for how many days after, but my phosphate didnt just go from 0.03 to .19ppm overnight. i dosed 3g of 40% water glass into 330g this morning.

So i think, though anecdotal, we have to acknowledge that there is an impact here.

Thoughts?

What silicate are you using?

 

[Randy Holmes-Farley Verified Community Expert]

I think that the question was not fully addressed. Someone posted anecdotal evidence that silica dosing impacts hanna ulr checker test results. Another person said, no that is wrong. And that was pretty much it.

I can tell you for sure that it does impact hanna ulr test results same day. I am not sure for how many days after, but my phosphate didnt just go from 0.03 to .19ppm overnight. i dosed 3g of 40% water glass into 330g this morning.

So i think, though anecdotal, we have to acknowledge that there is an impact here.

Thoughts?

It was answered, by the person who ran actual tests, and this the data behind the answer:

https://www.reef2reef.com/threads/high-silica-interference-with-po4-measurement.777022/

 

[Reef-Engineer]

The data and results suggest to me that there is interference at higher silica levels, and since many folks (including me) are dosing using a calculator and not testing (bad, i know) it is possible that our levels are now in the range of significant impact. Note the several cases where someone tests with api or red sea kits, gets expected values, then with hanna ulr and gets ~10x expectation.

Ill test over the next few days and see if the hanna result returns to expected levels as silica is consumed and post results. I wont use gfo, lanthanum, or do a water change.

Thanks for linking that other thread randy was an interesting read.

 

[Reef-Engineer]

My test results indicate a significant impact to phosphate ULR checker results from dosing waterglass 40% (pretty positive it was 40%), ~3grams, into 330G.

I was steady at 0.04-0.06 and then shot up to 0.19ppm (measured in evening) following a dose of silica (dosed in morning).

Two days later and I am back to 0.04ppm.

Now i don’t own a silica test kit which would really make the argument, but I would say this is at least a strong indication that for 24hrs after a sodium silica dose one should not trust a hanna ULR phosphate result.

Just so that the other reefers who experienced the same don’t think they are crazy.

 

[Randy Holmes-Farley Verified Community Expert]

My test results indicate a significant impact to phosphate ULR checker results from dosing waterglass 40% (pretty positive it was 40%), ~3grams, into 330G.

I was steady at 0.04-0.06 and then shot up to 0.19ppm (measured in evening) following a dose of silica (dosed in morning).

Two days later and I am back to 0.04ppm.

Now i don’t own a silica test kit which would really make the argument, but I would say this is at least a strong indication that for 24hrs after a sodium silica dose one should not trust a hanna ULR phosphate result.

Just so that the other reefers who experienced the same don’t think they are crazy.

That may be true, but it is also plausible that there is phosphate in the silicate solution.

 

[Miami Reef]

I bought silicate from loudwolf and got a large phosphate reading every time I dosed it. I ended up sending it to @taricha to figure out why.

We ended up discovering that filtering the silicate with a 1 um filter eliminated the phosphate spike.

The loudwolf silicate has cloudy and black particles inside.
Expand this quote to see the images Taricha took of my silicate

Thanks to @Miami Reef for the bottle of water glass. Here's what I found with the Loudwolf water glass silica dosing....
(tldr: nothing much different than what @Rick Mathew and I have measured previously.)

first, the bottle is a mess inside. lots of white solids and some dark particles.

I ran it through a 1um filter because what's specified in the MSDS is supposed to be a liquid and the solids are certainly not what we want.
"Substance name : Sodium Silicate Solution
Concentration : 41%
Formula : Na2SiO3 + H2O
CAS No. : 6834-92-0, 7732-18-5
Product code : LW-WATERGLASS
Synonyms : Waterglass"

I added measured amounts of the liquid to 1L of tank water to make 0, 1, 3, and 4ppm SiO2 solutions. I was over 30% too high, then I realized I goofed and made stock by volume without looking at the density. Correcting with the MSDS info...
"Relative density : 1.39 g/cm3 at 25 °C (77 °F)"
The hanna SiO2 measured comes out right at what was expected. So the liquid portion is exactly what it should be in SiO2.

Here's what the hanna ULR P checker gives for the various concentrations between 0 and 5ppm SiO2.

Stock SiO2 expected (ppm SiO2)	hi736 ULR P reading (ppb P)
0	30
0	23
1.40	27
1.40	22
4.17	27
5.56	30
5.56	43
5.56	32

This fits decently well in context with what Rick and I have measured before....Yellow stars are the new measurements.

(Green points are Miamireef data from post 23 using the hi736, so a little different but not hugely.)

So a couple of points:
1) the SiO2 in the loudwolf product doesn't interfere with the hanna ULR P checker any more than the small amount documented previously with other Silica sources.
2) I'd advise if you get the loudwolf product to filter the tons of solid material off and discard, if you have syringe filters that'd be ideal, but probably running it through a couple of coffee filters a time or two will work.
3) use dedicated hanna cuvettes for each test kit. Hanna sells extras. Using a cuvette to go back and forth between different tests causes weird results sometimes, even with lots of washes between.

 

[Idech]

I don’t use the Loudwolf product. Since I started this thread 2 years ago, I have been having dinos continuously and had to keep dosing silicate. I never dose high amounts as I did the first time though. Only 2 ml at a time, and maybe once a week, not even. I still can’t get reliable phosphate results from my Hannah ULR checker.

My product looks very pure. It’s translucent and has no dark particles in it.

 

[Miami Reef]

I don’t use the Loudwolf product. Since I started this thread 2 years ago, I have been having dinos continuously and had to keep dosing silicate. I never dose high amounts as I did the first time though. Only 2 ml at a time, and maybe once a week, not even. I still can’t get reliable phosphate results from my Hannah ULR checker.

My product looks very pure. It’s translucent and has no dark particles in it.

Do you use UV?

Edit: sometimes UV is the only thing that can knock it down for good.

 

[Randy Holmes-Farley Verified Community Expert]

. I still can’t get reliable phosphate results from my Hannah ULR checker.

What does unreliable mean to you?