Sulfur

[anthonygf]

Are you topping off with RO/DI?

Yes. 0 TDS, 1.06 sulfur. just noticed iron, manganese, strontium and boron all high in fresh salt mix; 9.85ppm, 37.85ppm, 10.31ppm, 6.2ppm respectively. I will be changing salt now. Iodine is also high. I will test Fritz mix with ICP just to make sure it is good and every other bag I open. I get the box with 4 bags so I can mix up the salt before opening bag.

 

[HuduVudu]

You are constantly adding sulfur through your top off. There is nothing consuming it so it is building up in your tank. You need to correct the problem with your RO/DI that is allowing sulfur through.

Here are my ICP tests:
RODI https://lab.atiaquaristik.com/timeline/34736
Tank https://lab.atiaquaristik.com/timeline/34735

Edit: Better links
RO/DI: https://lab.atiaquaristik.com/publicAnalysis/83593
Tank: https://lab.atiaquaristik.com/publicAnalysis/82208

 

[anthonygf]

You are constantly adding sulfur through your top off. There is nothing consuming it so it is building up in your tank. You need to correct the problem with your RO/DI that is allowing sulfur through.

Here are my ICP tests:
RODI https://lab.atiaquaristik.com/timeline/34736
Tank https://lab.atiaquaristik.com/timeline/34735

Thank you. I guess I will change out my membranes. But I still don't understand the numbers. If RO/DI water is 1.06ppm how can the salt mix be 1115ppm?

 

[Randy Holmes-Farley Verified Community Expert]

I don't think the math works out for the RO/DI to be an issue.

Suppose you replace 2% daily by evaporation and the RO/DI is 1 ppm S

Then you are boosting S (as sulfate, presumably) by 0.02 ppm per day.

In a year, you are only adding 7 ppm. Not significant.

 

[Randy Holmes-Farley Verified Community Expert]

Thank you. I guess I will change out my membranes. But I still don't understand the numbers. If RO/DI water is 1.06ppm how can the salt mix be 1115ppm?

Don't bother...

 

[Randy Holmes-Farley Verified Community Expert]

Salt mixes vary considerably in sulfate content (the third most abundant ion by weight in seawater). There's no evidence of whether that is any concern.

 

[anthonygf]

Thank you. I guess I will change out my membranes. But I still don't understand the numbers. If RO/DI water is 1.06ppm how can the salt mix be 1115ppm?

Which membrane is better 50 or 100 gallon per day?

 

[anthonygf]

Don't bother...

Thanks, I will just try new salt first. My membranes are maybe 3-4 years old. When is a good time to change them?

 

[anthonygf]

I don't think the math works out for the RO/DI to be an issue.

Suppose you replace 2% daily by evaporation and the RO/DI is 1 ppm S

Then you are boosting S (as sulfate, presumably) by 0.02 ppm per day.

In a year, you are only adding 7 ppm. Not significant.

WOW! Thanks for that.

 

[Randy Holmes-Farley Verified Community Expert]

Thanks, I will just try new salt first. My membranes are maybe 3-4 years old. When is a good time to change them?

When the rejection based on TDS before and after gets too high (from holes in it) or the flow gets too low (from clogging).

 

[anthonygf]

When the rejection based on TDS before and after gets too high (from holes in it) or the flow gets too low (from clogging).

Thanks Randy. I guess the flush valve will extend the life somewhat.

 

[chipmunkofdoom2]

I dose magnesium 3/4 tsp daily

What type of magnesium are you dosing? Is it chloride or sulfate?

 

[anthonygf]

What type of magnesium are you dosing? Is it chloride or sulfate?

Looks like it is both. Brightwell Aquatics Magnesion-P, magnesium sulfate and magnesium chloride.