STRAHN' - Tee- um. Sounds really cool. Remember looking it up on your periodic table in chemistry? Sr. Lot's of questions, but, never saw or heard anything more about it after school. So, why are there tons of green bottles of it on the shelves at the lfs? More importantly, should you dose your tank with it?
Back to Basic Chem
Strontium is Sr, periodic number 38, is present in very small amounts in SW. Concentration is about 90 micromoles/liter or 8ppm. It is present predominantly as the free ion, Sr2+. Most common combined forms are strontium sulfate (SrSO4) and strontium carbonate (SrCO4) and strontium bicarbonate (SrHCO3-)
Who Uses It?
1) ancantharia, a class of unicellular marine protozoa
2) Radiolaria, similar to acantharia
3) Gastropods, sea slugs, use it in their shells and in statocysts, organs that help them with balance
4) Cephalopods, cuttlefish, use it in their shells
5) Corals and calcareous algae
Are There Any Studies Done?
Not that many. Results from some studies have shown the following:
1) Raising strontium levels raises rates of incorporation into corals
2) studies say little about whether strontium is necessary for calcium uptake
3) Strontium MAY increase the level of calcium at the outer mucin levels of corals that MAY benefit them by assisting with calcium uptake
Can I Poison My Tank With It?
Well, yes and no. At normal levels in the aquarium, Sr is not toxic. However, with injudicious use, some crabs show toxicity starting at 38ppm....some shrimp at 150ppm...some fish at 1500 ppm.
Does Anyone Know What my Level Is?
Without measuring it, it is not possible to know for sure without a test kit. However, one study of the average marine aquarium showed levels to average about 4-10 ppm with an average of 6.8ppm. No need to dose at these levels.
What is Known About Sr in My Salt Mix or Calcium Supplements?
1) Instant Ocean mixed to a salinity of 35% was shown to contain 15ppm Sr
2) SeaChem adds Sr it to Reef Complete, a calcium supplement
3) Most calcium supplements/limewater/kalkwasser will naturally contain some strontium, so, dosing may increase your levels
4) Fish food contains Sr, eg, 5 gs of brine shrimp will add 25 ppms Sr per 100 gallons of water; 5 g's of Formula One flake will add 12 ppm
How Do I Measure Strontium?
There are basically two kits available, Seachem and Salifert. I have not used them personally, but, they are supposed to be tedious since strontium is similar in size as magnesium and calcium which are in larger concentrations in the water. Seachem's kit offers 50 tests and takes 10 minutes to perform. It costs $33.99 on drsfostersmith.com. Salifert's strontium test kit states 25 tests on the box, but, marinedepot.com claims it will do 40 tests. Their site has it for 35.95. The instruction sheet is lengthy.
General Recommendations About Strontium in Your Tank
1) Strontium should be maintained at levels approaching that of SW
2) Toxicity can occur at high levels in some marine species
3) There is strong evidence to show that some marine animals need strontium to survive but NONE that we really keep in our nano tanks
4) There is SOME evidence that depletion of Sr MAY affect the health of corals that we DO keep in our nano tanks
5) Levels in the aquarium should be maintained at 6-15ppm. Higher may necessitate a water change. Lower and supplementation may be beneficial. MOST TANKS MAINTAIN A NORMAL Sr level with water changes.
6) As always DO NOT DOSE YOUR TANK WITH STRONTIUM IF YOU HAVE NOT MEASURED YOUR LEVELS. If you do dose, dose with Sr and not Sr combined with other elements (molybdenum, eg). As you can see, dumping strontium into your tank without measuring makes NO SENSE at all.
As always, feel free to post your thoughts and experiences.
SH
http
/www.advancedaquarist.com/issues/nov2003/chem.htm
Back to Basic Chem
Strontium is Sr, periodic number 38, is present in very small amounts in SW. Concentration is about 90 micromoles/liter or 8ppm. It is present predominantly as the free ion, Sr2+. Most common combined forms are strontium sulfate (SrSO4) and strontium carbonate (SrCO4) and strontium bicarbonate (SrHCO3-)
Who Uses It?
1) ancantharia, a class of unicellular marine protozoa
2) Radiolaria, similar to acantharia
3) Gastropods, sea slugs, use it in their shells and in statocysts, organs that help them with balance
4) Cephalopods, cuttlefish, use it in their shells
5) Corals and calcareous algae
Are There Any Studies Done?
Not that many. Results from some studies have shown the following:
1) Raising strontium levels raises rates of incorporation into corals
2) studies say little about whether strontium is necessary for calcium uptake
3) Strontium MAY increase the level of calcium at the outer mucin levels of corals that MAY benefit them by assisting with calcium uptake
Can I Poison My Tank With It?
Well, yes and no. At normal levels in the aquarium, Sr is not toxic. However, with injudicious use, some crabs show toxicity starting at 38ppm....some shrimp at 150ppm...some fish at 1500 ppm.
Does Anyone Know What my Level Is?
Without measuring it, it is not possible to know for sure without a test kit. However, one study of the average marine aquarium showed levels to average about 4-10 ppm with an average of 6.8ppm. No need to dose at these levels.
What is Known About Sr in My Salt Mix or Calcium Supplements?
1) Instant Ocean mixed to a salinity of 35% was shown to contain 15ppm Sr
2) SeaChem adds Sr it to Reef Complete, a calcium supplement
3) Most calcium supplements/limewater/kalkwasser will naturally contain some strontium, so, dosing may increase your levels
4) Fish food contains Sr, eg, 5 gs of brine shrimp will add 25 ppms Sr per 100 gallons of water; 5 g's of Formula One flake will add 12 ppm
How Do I Measure Strontium?
There are basically two kits available, Seachem and Salifert. I have not used them personally, but, they are supposed to be tedious since strontium is similar in size as magnesium and calcium which are in larger concentrations in the water. Seachem's kit offers 50 tests and takes 10 minutes to perform. It costs $33.99 on drsfostersmith.com. Salifert's strontium test kit states 25 tests on the box, but, marinedepot.com claims it will do 40 tests. Their site has it for 35.95. The instruction sheet is lengthy.
General Recommendations About Strontium in Your Tank
1) Strontium should be maintained at levels approaching that of SW
2) Toxicity can occur at high levels in some marine species
3) There is strong evidence to show that some marine animals need strontium to survive but NONE that we really keep in our nano tanks
4) There is SOME evidence that depletion of Sr MAY affect the health of corals that we DO keep in our nano tanks
5) Levels in the aquarium should be maintained at 6-15ppm. Higher may necessitate a water change. Lower and supplementation may be beneficial. MOST TANKS MAINTAIN A NORMAL Sr level with water changes.
6) As always DO NOT DOSE YOUR TANK WITH STRONTIUM IF YOU HAVE NOT MEASURED YOUR LEVELS. If you do dose, dose with Sr and not Sr combined with other elements (molybdenum, eg). As you can see, dumping strontium into your tank without measuring makes NO SENSE at all.
As always, feel free to post your thoughts and experiences.
SH
http
/www.advancedaquarist.com/issues/nov2003/chem.htm
