Tunze Reef Salt

I’ve been using Reef Crystals aquarium salt for years now, and used the last of the bucket to fill up and cycle the Elos Mini. I thought it might be interesting to use a new salt mix. With the sheer selection of reef salts out there, it can be a pretty confusing choice. The aquarium salt test results from AWT, Inland Reef Aquaria, and the various salt parameters and opinions seen posted on the reef boards definitely do not make the decision any easier.

There are varying opinions as to how necessary the additions of some elements are in the reef tank, such as potassium or iodine. I’d prefer add these by hand later, if at all, via the plethora of available additives. But we can’t deny the importance of the triad – Calcium, Alkalinity & Magnesium. I’ve found Billybeau1′s test results of these critical three elements to be most helpful in determining my choice for the next salt I use. I could read a third party or manufacturer’s analysis until I’m blue in the face, but without access to a lab, it can only be taken at face value – a hobbyist testing with hobbyist kits, is the closest analysis most of us will get.

Tunze's Analysis
Tunze's Analysis ...

While browsing the list of his test results, one result stood out to me – Tunze Reef Excel Lab Marine Salt (that’s kind of a mouthful). My preference is to target 380 – 400 mg/l of Calcium, 1300 mg/l of Magnesium, and NSW levels of alkalinity, about 7 dkH.

Billy’s tests of Tunze’s salt, mixed at 35 ppt (1.0264) @ 25* C (77* F), resulted in 420 Ca, dkH 9.5 and 1350 Mg. Sounded good to me.

So, I bought a bag, mixed it up. My results @ 77*, 35ppt:

Alkalinity (dkH)
Elos – 9.5
API 1 ~ 9 – 10
API 2 ~ 9 – 10
Seachem ~ 9 -10

Calcium
Elos – 440
Salifert – 450

Magnesium
Elos ~ 1200 – 1250
Salifert ~ 1200

Not sure, but I am assuming my Mg test results to be lower than both billybeau’s and Tunze’s analysis since Mg tends to settle towards the bottom of the mix. I also lost a few cups due to poorly packaged shipment (packed underneath 15 lbs of live rock with no padding between?!) I do not have the means to mix up 60 whatever gallons at the moment, so my option is to dump the bag into a bucket with lid and shake the hell out of it… which is exactly what I did. I then mixed 5 gallons up.

If memory serves, it took roughly 2.5 cups in 5 gallons to reach 35ppt.

Reef Crystals have been great the last 5 or 6 years, though recently too high in Calicium for me, and Instant Ocean wonderful before that. Tunze is a good company and I like those Ca / Mg / kH numbers – just enough to give a boost with a water change, but not so much that it skews my preferred reef chemistry. Not to mention the price is somewhat comparable…

50 gal Reef Crystal mix – $19.99 about $0.40 per gallon
63.4 gal Tunze bag mix – $26.90 about $0.42 per gallon

I am not recalling what specific gravity RC is supposed to be mixed to. Tunze says 17.6 lbs. sack in 63.4 US gallon will hit 1.020 @ 68*F. Assuming most reefers are shooting for something like 1.024 – 1.026, it may take a bit more Tunze salt to reach the equivalent specific gravity of Reef Crystals. It’s close enough for me…

Anyway, it’s not pixie dust – just another synthetic salt with numbers I like.

Hope my tank looks good.