Low sulphur levels is it an issue?

[Randy Holmes-Farley]

Sulfur in my aquarium is 740.1 mg/l.

Ati ref value against salinity (36,56 PSU) is at 976,2 mg/l.

That means I need to add 236,1 mg/l into my 2000 liter system.

The salinity is going to rise with this addition and is already pretty high, so correcting back to 35 ppt is going to have a depressive effect on other things.

Anhydrous sodium sulfate (the usual form sold) is 68% sulfate and 22.5% S by weight.

Thus, if you need 236 mg/L of S added per liter, you need 1.05 grams per L of Na2SO4 per liter.

In 2000 L, you will need 2.1 kg.

That addition will boost salinity by 1 ppt to 37.5 ppt. If you drop back to 35 ppt, everything (including S) will decline to 93% of its current or boosted value.

 

[Dimorb]

How much would you use to dilute this?

I tried to mix in 1 liter but it hardens and becomes solid..

Perhaps I need to use more.. 5 liters for example.. would there be any risk if I use an old nopox container?

 

[Randy Holmes-Farley]

How much would you use to dilute this?

I tried to mix in 1 liter but it hardens and becomes solid..

Perhaps I need to use more.. 5 liters for example.. would there be any risk if I use an old nopox container?

Wikipedia gives the solubility as about 280 g/L, so well more than 5 L RO/DI.

You also can consider slowly adding it directly to a sump or overflow as a dry powder, as long as you can ensure it isn't going to get to a delicate creature as an undissolved particle.

 

[Dimorb]

Wikipedia gives the solubility as about 280 g/L, so well more than 5 L RO/DI.

You also can consider slowly adding it directly to a sump or overflow as a dry powder, as long as you can ensure it isn't going to get to a delicate creature as an undissolved particle.

Thank you.

I started to mix before I had to go away and when I came back it was all hard. Like stone. Im trying to mix with a pump in a bucket to give it some temp at the same time.. have to wait and see how that goes.

When mixing 2.1 kg into 5 liters what do you recommend I should dose each day?

 

[Randy Holmes-Farley]

Thank you.

I started to mix before I had to go away and when I came back it was all hard. Like stone. Im trying to mix with a pump in a bucket to give it some temp at the same time.. have to wait and see how that goes.

When mixing 2.1 kg into 5 liters what do you recommend I should dose each day?

It won’t get that high at room temp. I’d add it over 5 days to limit the salinity jump.

 

[Dimorb]

Hello again and a big thank you for all your help.

This is what I've done so far.

Mixed 2,1 kg Sulphate from Triton together with 5 liters of RODI water. (Still cant find what's in the package from Triton, e-mailed them but no answer so far)

Connected a doser to dose sulphate solution as wanted and/or needed.

Connected another doser to remove water from the aquarium, to prevent large changes in salinity.

Last questions.

Q1. Is there a specific amount of water that should be removed in relation to how much solution is dose into the aquarium?

For example I'm planning to add the entire solution over a period of 14 days.

That will give a daily dose of approx 357 ml each day and divided into 24 hours it will result in a 14,9 ml dose each hour. I believe this will give me plenty of time to manage other parameters and total salinity, but should I remove the same amount of aquarium water - more - less?

By the way.. My salinity is 34,8 NOT 36,5 as the previous ICP shows. I've lowered it over a course of 2 weeks since I got the ICP results back.

Q2. Will this knowledge affect the calculations and amount of sulphate needed to raise sulfur 236 mg/l in my 2000 liter system or does it only affect the requested amount of sulfur in the system?

I dose balling and normally I remove some water at random, when relocating corals to others or skimmer removes some.. this keeps the salinity within my preferred range (34,8-35,2 PSU) -

Q3. Is there a relationship between what is dosed and the amount of water that should be taken out in total? For example if I dose 200 ml from each container should I remove 600 ml of water to even the salinity out?

@Lasse
@Randy Holmes-Farley

 

[Dimorb]

In addition to the previous post.

It seems I cant keep it dissolved. 2 kg mixed in 5 liters. Stays liquid in the container but "freeze" to crystal in tube.

If pressing the container on the sides I can hear it crackle so it's hardens in the container also.. only take more time.

When placed into a bucket together with a pump it stays dissolved. Why is that and what to do?

 

[Dimorb]

Wikipedia gives the solubility as about 280 g/L, so well more than 5 L RO/DI.

You also can consider slowly adding it directly to a sump or overflow as a dry powder, as long as you can ensure it isn't going to get to a delicate creature as an undissolved particle.

Terrible sorry.. didnt read good enough.
Need more RO water to mix.

Do you have any thougth on the other questions?

 

[Randy Holmes-Farley]

In addition to the previous post.

It seems I cant keep it dissolved. 2 kg mixed in 5 liters. Stays liquid in the container but "freeze" to crystal in tube.

If pressing the container on the sides I can hear it crackle so it's hardens in the container also.. only take more time.

When placed into a bucket together with a pump it stays dissolved. Why is that and what to do?

Yes, that's what I said. It takes more than 5 L. The pump may be warming the water a bit, increasing solubility

Here's a way to estimate water removal. If the salinity is 37 ppt and you want 35 ppt, you need to reduce the volume to 35/37 x 2000L and replace with RO/DI.

So it is removing 108 L. But 37 ppt is not exactly your situation. It's just an example.

 

[Randy Holmes-Farley]

The ratio of the solution you are adding to the solution you are removing will depend on the concentration in the solution you are adding.

Suppose you use 10 L total, so it is 2,100 g/10 L or 210 g/L. Seawater is about 35 g/L, so the dosed solution is 6x more potent and you'd remove 6x of tank water.

 

[Dimorb]

The ratio of the solution you are adding to the solution you are removing will depend on the concentration in the solution you are adding.

Suppose you use 10 L total, so it is 2,100 g/10 L or 210 g/L. Seawater is about 35 g/L, so the dosed solution is 6x more potent and you'd remove 6x of tank water.

Thank you again.

I've been using approx 25 liters to mix.. so it would be 2100 g/25 L = 84 g/l so the dosed solution is 2,4 times natural seawater.

I dose 48 x 15 ml each day. That's 720 ml.

If I understand you correctly I should remove 720 x 2,4 each day.. in total 1728 ml each day and replace with RODI water.. is that correct?

 

[Dimorb]

I'm not sure why my math doesnt add up.

I calculate it like this..

I mixed 2000 g powder of sulphate to add 235ish mg/l sulfur in a 2000 liters system into 25 liters RODI water.. 2000 g / 25 L = 80 g/L (in solution)

PSU at this moment measures 1,0228 g/cm3 equal to 1,0228 kg/l (according to GHL probe). That's the same as 34,4 PSU. (in the aquarium)

So 80 / 34,4 = 2,33

I dose 720 ml/day of the solution... I should remove 720 x 2,33 = 1674 ml/day (should I not?)

All in all since I started (22th dec) I've dosed 2737 ml of the sulphate/sulphur solution and removed 27626 ml seawater from the system. GHL probe went down from 1,0233 to 1,0228 kg/L but are stable last 24 hours.

Could this be correct? How? Is it possible my probe shows wrong value?

The calculations are only based on the addition of sulphate/sulfur solution and not the fact that I'm adding balling each day. I normally add kH (24x12 ml), CA (24x6 ml) NACL- (24x6 ml).

I use the following mix of balling:

Dunk 1
450 gram Kalciumkloriddihydrat, CaCl2 • 2H2O

Dunk 2
128 gram Natriumkarbonat, Na₂CO₃,
82 gram Natriumvätekarbonat, NaHCO₃

Dunk 3
128 gram Natriumkarbonat, Na₂CO₃,
82 gram Natriumvätekarbonat, NaHCO₃

Dunk 4
69 gram Magnesiumkloridhexahydrat, MgCl2. 6H2O
170 gram Natriumkloridfritt salt, NaCl FREE Salt.