Kalkwasser advice needed

[john.m.cole3]

Hello fellow Reefers,
I am having the hardest time keeping my levels stable via manual dosing. My tank is a year old and I can't grow any corals but mushrooms. I've heard good things about using a kalkwasser solution in your ATO reserve.

Ca - 370
Alk - 7.6
Mag - 1020
Nitrate 10 - 25
Phosphate - 0.04
Temp - 78
Ph - 8.2
My question is where do I start with how much Kalk do I add to my 5 gallon top off bucket? What is a good brand of Kalkwasser to buy? And will I need to continue to manually dose magnesium? I am dosing 30 ml/day vinegar at the time. Running a mix of carbon and GFO in a single reactor. Weekly 10% water changes w/ Reef Crystals.

 

[Randy Holmes-Farley Verified Community Expert]

Limewater (kalk) is a fine choice, at least when the demand is not too high. It is all I use.

First, let's get the levels corrected, then look to routine dosing.

What salinity are you using? Magnesium and calcium seem low for Reef Crystals at 35 ppt (sg = 1.0264).

 

[john.m.cole3]

1.026
I agree with them being low. I'm using Salifert test kits for evrything and Hanna for Alk and phosphate

I only have a blasto and hammer frag and the rest are soft corals (mushrooms and zoas)

 

[Cory]

What are you measuring salinity with?

 

[Randy Holmes-Farley Verified Community Expert]

I'm suspicious that either the salinity is lower than you think, or the magnesium is higher than you think since Reef Crystals has a lot more than that.

 

[john.m.cole3]

so recalibrate my refractometer with a 35 ppt solution first?

 

[Randy Holmes-Farley Verified Community Expert]

If you have fluid, that would be the first thing to do.

What brand magnesium kit? A lot of people have issues with the Red Sea.

 

[john.m.cole3]

Salifert

 

[john.m.cole3]

using Kent marine products for manual dosing at this time

 

[Randy Holmes-Farley Verified Community Expert]

If magnesium really is that low and it is not a salinity problem, it will take a huge amount to raise it and you may not have enough available. In that case a DIY may be preferred.

This calculator shows what would be needed:

http://reef.diesyst.com/chemcalc/chem_calc3.html

I'd also try the Salifert kit on some new Reef Crystals made after you recalibrate your refractometer.

 

[john.m.cole3]

yeah it says I will need 713.8 ml or 24.1 ounces of Kent tech M which I have. I ordered some calibration fluid for my refractometer, so I will re-calibrate my refractometer before taking further action.

 

[Randy Holmes-Farley Verified Community Expert]

Ok sounds good.

Don't boost it all the way at once. Maybe 25 ppm per day.

 

[ksed]

Randy,
I have been using R/C salt for some time now and all is good as far as the major elements. But I have heard of some complaints lately. Perhaps it may be a minor batch problem. Take a look here. The dates are all over the place but there's been some recent complaints as well.

http://www.reefcentral.com/forums/showthread.php?t=2485308

I'm suspicious that either the salinity is lower than you think, or the magnesium is higher than you think since Reef Crystals has a lot more than that.

 

[john.m.cole3]

interesting link. I will test my water on Friday after it mixes for 24 hours

 

[Randy Holmes-Farley Verified Community Expert]

It is always possible there's a bad batch,and you may have one, but as I note in the copied post below, testing is clearly a problem, and IMO, more likely in any given case than a bad batch. Some cases may also be people mad at Instant Ocean or are competitors trying to mess with their reputation.

Reef Crystals tests every pallet with QC tests before it is released. So somehow to have a bad batch you not only have to make it, but then get it through QC.

Here's a copy and paste from a recent thread:

As an example of how I think "bad batches" are often test error, this is the sort of result that proves test kit error exists.

This person was testing many different kits on the same water and comparing them.

https://www.reef2reef.com/threads/t...rt-elos-redsea-hanna-etc.222909/#post-2568694

For magnesium, he got

1470-1480 (Salifert)
1100 (Red Sea "Curse it and crush it! We hates it forever!" Pro Mg)

So if he had only used the Red Sea, he'd say he got a bad batch. If he only used Salifert, he'd say he had way more than enough magnesium.

I'm not sure if either is correct, but definitely at least one is not.

 

[ksed]

Agreed

 

[john.m.cole3]

After calibrating my refractometer with 35 ppt solution, my salinity measured 1.020... How fast should I raise it up? I also have a fresh batch of SW mixing now that I will test once I get home tonight.

 

[twilliard]

Like anything dont raise it too fast

 

[cmcoker]

After calibrating my refractometer with 35 ppt solution, my salinity measured 1.020... How fast should I raise it up? I also have a fresh batch of SW mixing now that I will test once I get home tonight.

Slow, no more than. 0.002 over 24hrs to allow your fish to acclimate. I would just put salt water in your ATO to raise it slowly, then test test test

 

[john.m.cole3]

Would raising my salinity by .002 a week for 3 weeks be considered too fast?