First ICP test results - I'd appreciate some feedback. running Sulfur Reactor

[MeanGreenStompa]

(results below)
Hello, here's the story. 180 gallon display, 300 gallons overall w sump and display refugium which ended up being the relocation for my BTAs and maroon clowns.
It's been running for a couple of years. I have always had a big problem w nutrients being v high. I have a big external RO skimmer, I run GFO and I have an algae reactor and I'm still dosing phosphat-E to drive down phosphate, it's a battle. I sorted nitrate, however, almost immediately that I added a sulfur reactor.

I have just begun, with some success, growing easier sps corals. Some of my LPS are doing well, others though do not do well at all and while they don't die, they remain closed/receded like skin stretched over stone. I do have a couple of 'likely suspect' species of fish, flame angel and foxface, but I have never observed 'nibbling' and I sit there and watch that tank for hours.

I just got the results of the ATI test back and it seems sobering. I have been dosing Alk to counter the sulfur reactor, and had been adding kalk to the ATO water. Seeing the calcium is too high I guess it's time to halt that and just up the alk dosing instead? IS the sulfur 'life threatening'? Do I need to shut down the reactor?

ANY and ALL advice to steer my aquarium back on track would be appreciated. I am also confused by the sodium, the oddly high bromide, etc etc. I have begun dosing the Iodine as recommended.

 

[Randy Holmes-Farley]

Do you do water changes?

 

[MeanGreenStompa]

Yes, 10% per month, reef crystals.

 

[MeanGreenStompa]

A large amount of the rock was second hand, I have always wondered if there was a phosphate soak up in it's history, but then I'd imagine it would start going down over time. I do feed 'well' and have a good number of fish, but nothing OTT and I overwhelmingly use frozen foods that I strain with RO.

 

[MeanGreenStompa]

I'd also really like understanding on how the salinity is great but the sodium is too high and the chloride is too low? Isn't the sodium chloride the salt?

 

[Randy Holmes-Farley]

I'd also really like understanding on how the salinity is great but the sodium is too high and the chloride is too low? Isn't the sodium chloride the salt?

Chloride is low because sulfate is high. Together, the sum of those two is basically pegged by the salinity.

The sodium value may have some error in it, and it is partly high due to salinity being high.

In your sulfur denitrator, do you pass the effluent over calcium carbonate? if so, that's why calcium is high.

 

[MeanGreenStompa]

Chloride is low because sulfate is high. Together, the sum of those two is basically pegged by the salinity.

The sodium value may have some error in it, and it is partly high due to salinity being high.

In your sulfur denitrator, do you pass the effluent over calcium carbonate? if so, that's why calcium is high.

Yes, I was advised to run it through the crushed coral to balance it out, didn't think it would swing it upwards but equalize. I thought it might have been the kalk in the RO ATO water which I was trying to use to boost alk, but I'm just dosing the alk from 2 part to do so from now on. Do you think I should remove the crushed coral?

 

[MeanGreenStompa]

I'm using the 2 little fishies 'reborn' calcium reactor media.

 

[Randy Holmes-Farley]

Yes, I was advised to run it through the crushed coral to balance it out, didn't think it would swing it upwards but equalize. I thought it might have been the kalk in the RO ATO water which I was trying to use to boost alk, but I'm just dosing the alk from 2 part to do so from now on. Do you think I should remove the crushed coral?

A sulfur denitrator either depeltes alkalinity, or if you choose to pass it over calcium carbonate, it raises calcium. There's no solution to that except either dosing extra alkalinity or dealing with the added calcium.

I discuss that here:

Nitrate in the Reef Aquarium - REEFEDITION

Nitrate is an ion that has long dogged aquarists. It is typically formed in aquaria through the digestion of foods, and in many aquaria it builds up and can be difficult to keep at natural levels. In the past, many aquarists performed water changes with nitrate reduction as one of the primary...

www.reefedition.com

Sulfur Denitrators

In these systems, bacteria use elemental sulfur and produce N2 from the sulfur and nitrate according the following equation (or something similar):

2 H2O + 5 S + 6 NO3– → 3 N2 + 5 SO42- + 4 H+

The production of acid (H+) in this reactor can tend to reduce the aquarium alkalinity. It has also been suggested to pass the effluent of such a reactor through a bed of aragonite to use the acid (H+) produced to dissolve the calcium carbonate, and thereby provide calcium and alkalinity to the aquarium. While that is a fine idea, it doesn’t add much calcium and alkalinity to most aquaria.

To estimate the magnitude of the effect, we start with a liberal estimate of how much nitrate might be removed. Say 10 ppm of nitrate per week.

10 ppm nitrate = 0.16 mmole/L of nitrate

Since 4 moles of H+ are produced for every 6 moles of nitrate consumed, this will produce

0.107 mmoles/L of H+ per week

How much calcium this could produce?

Assume that it takes one proton to dissolve one calcium carbonate:

CaCO3 + H+ → Ca2+ + HCO3–

Clearly, this is a substantial overestimate because much of the acid will be used up driving the pH down to the point where CaCO3 can even begin to dissolve. Consequently, we have an upside limit of 0.107 mmoles of Ca2+ per week. Since calcium weighs 40 mg/mmol, that’s 4.3 ppm Ca2+ per week.

For comparison, an aquarist adding 2% of the tank volume in saturated limewater daily is adding on the order of 16 ppm of calcium per day. Consequently, this method may not be especially useful for maintaining calcium. Additionally, the acid produced will have a long term lowering effect on the alkalinity. In fact, it is double dipping on the alkalinity depletion since alkalinity is consumed when the nitrate is produced, and again when it is removed in the denitrator. So if you use a sulfur denitrator, be sure to monitor the alkalinity in the aquarium.

 

[MeanGreenStompa]

A sulfur denitrator either depeltes alkalinity, or if you choose to pass it over calcium carbonate, it raises calcium. There's no solution to that except either dosing extra alkalinity or dealing with the added calcium.



The production of acid (H+) in this reactor can tend to reduce the aquarium alkalinity. It has also been suggested to pass the effluent of such a reactor through a bed of aragonite to use the acid (H+) produced to dissolve the calcium carbonate, and thereby provide calcium and alkalinity to the aquarium. While that is a fine idea, it doesn’t add much calcium and alkalinity to most aquaria.

In my extremely limited understanding of this, I understood that alkalinity was crashing because the calcium was being released and therefore 'increased calcium = decreased alkalinity' so I have been dosing alk alone via a dosing pump (just one half of 'two part'.

Earlier you'd said
"Chloride is low because sulfate is high. Together, the sum of those two is basically pegged by the salinity." and I was interested in understanding a) is low chloride a bad thing and b) is high sulfur also a bad thing or are they red on the results because they are high and low compared to seawater?

Is there another process I could be running to reduce that sulfur and allowing the chloride to, from what you're saying, get back to better numbers with the absence of some of that sulfur?

I am also thinking of increasing the water changes up to weekly, this sounds like a good way of rounding my numbers back to where they should be?

Thank you for your help with this btw, it is appreciated greatly.

 

[Randy Holmes-Farley]

Water changes will stabilize the chloride to sulfate ratio toward what is in the salt mix.

Otherwise, I see no good way to deal with the slow rise of sulfate from a denitrator.

Alk is not falling due to calcium rising , it is falling because the sulfur denitrator process consumes it directly.

If you then pass the low alk low ph water over calcium carbonate to try to offset the low alk and low pH by dissolving calcium carbonate, pH and alk and calcium rise.

You cannot completely offset the alk and pH issues this way, but if you use the process to any degree, calcium necessarily rises .