Why do we test for strontium?

[Bristle Worm]

What does this element do for our reefs? Is it critical to test for or just a nice to know? If so why?

[scubadude]

Strontium is a trace element and should be replenished with a periodic water change. It is my understanding that Strontium and Magnesium are in direct corelation with your Ca and Alk levels....so if you where to have a hard time reaching your Ca and Alk levels you might want to check your Str or Magn levels. But FWIW I wouldnt worry too much about Strontium....Magnesium is probably the first place I would go.

[Ninong]

What does this element do for our reefs? Is it critical to test for or just a nice to know? If so why?

It is only critical to test for it if you are planning on adding it. Strontium is one of those elements that can be dangerous at elevated levels. It is not known what, if anything, actually requires strontium. It is very similar to calcium chemically and is deposited in the coral skeleton at the same ratio that it exists in natural seawater. Elevated levels of strontium will interfere with calcium deposition in corals. Elevated levels of strontium in humans will result in deformed bones. Some "hobby" authors recommend regular dosing of strontium but I would never dose it without checking for it first because there may not be any need to add it if you perform water changes every two or three months or so. I know some very advanced reefkeepers who have never dosed strontium.

As Scubadude menention, magnesium should be maintained near NSW levels because very low magnesium will make it difficult for you to maintain appropriate calcium and alkalinity levels. Magnesium should be maintained somewhere near 1300 ppm. I usually don't bother to add any magnesium chloride to my tank unless my levels drop below 1100 ppm. I have never added strontium because I have never tested for it. Strontium in NSW averages 8-9 ppm.

Dr. Randy Holmes-Farley has written a very good article on strontium: http://www.advancedaquarist.com/issues/nov2003/chem.htm

[Bristle Worm]

Yeah, I really felt strontium was not required since there is so little talk about it on the boards. Per Ninong, I was suprised to learn that it could be dangerous at elevated levels as a blocking agent to normal calcium carbonate deposition. I guess that's one less test kit and/or supplement to buy.

As for magnesium, my understanding is that magnesium prevents calcium carbonate from forming on your equipment through blocking the precipitation of calcium carbonate crystals on said equipment, thereby freeing up this calcium carbonate for your corals.

Based on that you really don't even need to test for Magnesium as long as your calcium and hardness levels are OK.

[Ninong]

Based on that you really don't even need to test for Magnesium as long as your calcium and hardness levels are OK.

I would test for magnesium. In fact, I do test for it every two or three months. You aren't going to run into problems with your calcium levels as a result of low magnesium until your magnesium gets very low. The lowest I have tested is 1050 ppm and I gradually added magnesium chloride to bring it back up above 1200 ppm. I don't have a calcium reactor. If you have a calcium reactor your magnesium levels should be easier to maintain and if they start to fall, you can throw a little dolomite in the media chamber to raise the magnesium output from your calcium reactor.

I think it is a good idea to maintain your magnesium near NSW levels. I think it is a good idea to maintain most of your elements near NSW levels whenever possible but some are more important than others. I test my tank regularly (every three months or so) for iodide/iodate. So far the test results have always been equal to or higher than NSW levels without adding any iodine supplements. I'm using a Salifert iodine test kit. My total iodine levels are always at least 0.06 ppm (NSW levels) but usually the test comes back at 0.20 ppm (3 times NSW). I'm not all that thrilled with Salifert's iodine test kit but I know that some of the others on the market are really junk because they don't measure all of the forms of iodine -- iodide, iodate and molecular iodine.

I might get a strontium test kit but I have heard that they aren't all that reliable. I wouldn't add strontium to my tank unless I knew for sure that my levels were below 7 ppm. However, I am not nearly as concerned about my strontium levels being slightly lower than normal as I am my magnesium levels. Or, to be more precise, my magnesium levels dropping considerably below normal. As long as my magnesium is at 1200 ppm or higher, I'm happy. I just don't like it dropping below 1150 ppm.

[Bristle Worm]

Therefore in the final analysis: Why worry about magensium, strontium, or anyother trace element level if your calcium and your carbonate levels are good?

Magensium supports bio-available carbonate levels. So if you are OK on carbonate, there is no need to worry about magensium.

Strontium: Nobody seems to know what strontium does except screw things up in elevated quantities.

Iodine: what does this do? (something about bivalves) However I grew a Derasa for a over year to twice its size without this supplement. Though I did have difficulties with the Maximas

Iron: Ok I could already grow Algae long before I added Iron. hmmmm

Molybendum: I don't know if I can even spell that right much less find a beneficial purpose for it in my tank

Maybe these supplements really don't add much value to a reef tank but rather add value to the manufacturer's bottomline.

[Ninong]

Therefore in the final analysis: Why worry about magensium, strontium, or anyother trace element level if your calcium and your carbonate levels are good?

I wouldn't carry things that far. I think it is important to maintain most elements, especially magnesium, near NSW levels. NSW concentration for magnesium is ~1285 ppm. I wouldn't want to see my magnesium drop below 1150 ppm for a variety of reasons in addition to the fact that it supports higher levels of calcium and carbonate than would be possible otherwise. Magnesium is important to many organisms and I don't think it would be wise to not pay attention to it in a reef tank.

Some artificial salt mixes are deficient in magnesium and others have excess magnesium. You need to test your freshly made up saltwater if you want to know how you stand in that department. If your salt mix is one of the ones with higher levels of magnesium, you may never have to worry about low levels in your tank. If you are using a calcium reactor and the calcium carbonate media has the correct amount of magnesium in it, then you may never have to worry about adding magnesium. If your media is a little low in magnesium, you could always mix in about 10% dolomite with your media to balance things out better.

I don't have a calcium reactor. I use limewater and only limewater. A lot of the magnesium in my calcium hydroxide doesn't get into the tank because it settles out as magnesium hydroxide first. If I were using a salt that has excess magnesium, I would probably be OK, but I'm not. I'm using a salt mix that is slightly low in magnesium according to my own tests. The manufacturer insists that it isn't low, but I think it is just a little low. Because I use limewater and because my salt mix is a little low in magnesium, I have to test my magnesium levels from time to time and supplement as necessary. I have been using magnesium chloride because I usually am not all that low. I guess I could use epsom salts if I wanted to be cheap but so far I haven't.

Magensium supports bio-available carbonate levels. So if you are OK on carbonate, there is no need to worry about magensium.

I think it would be wise to keep your magnesium levels +/- 150 ppm from NSW levels of 1285 ppm.

Strontium: Nobody seems to know what strontium does except screw things up in elevated quantities.

Many hobbyists seem to think that adding strontium is beneficial. Personally I don't think it is necessary to maintain strontium at levels above NSW levels of 8-9 ppm and I have never even tested for it in my tank. I sort of think that my strontium levels are reasonably maintained by water changes every couple of months. I will probably try to get a strontium test kit if I can find one that works just to see what my levels really are. If I am convinced that my strontium levels are much below NSW levels, I will add strontium. I just wouldn't add it without knowing where I am to begin with.

The same authors who recommend blind additions of strontium on a regular basis also recommend blind additions of iodine on a regular basis. I got into an email correspondence with one owner of an LFS who claims to be a marine biologist and asked him if he had ever tested his tank for either strontium or iodine. His response was that it wasn't necessary to test for either because it was a well known fact that both are depleted quickly and need to be added on a regular basis. The exchange came to a speedy conclusion when he freaked out after I sent him an email telling him he was misleading his customers just to sell all the additives he carries. Oh, he also told me that crustaceans would have problems molting if you didn't add iodine to your tank regularly. The idea that our tanks might already have more than NSW levels of iodine without any special additions was totally unacceptable to this guy.

Iodine: what does this do? (something about bivalves) However I grew a Derasa for a over year to twice its size without this supplement. Though I did have difficulties with the Maximas

This one I do test for every few months. I have never added iodine and I have never measured iodine levels below NSW levels in my tank.

Iron: Ok I could already grow Algae long before I added Iron. hmmmm

Iron is necessary in photosynthesis. Does that mean you have to add it? I doubt it. Some people do like to add it. It certainly won't hurt anything if you add it in moderation. The fishing industry has been dumping hundreds of tons of iron oxide into the southern ocean in an attempt to increase the growth of phytoplankton and thus increase the fish populations.

Iron is important and necessary but I'm not sure you really have to add it.

Molybendum: I don't know if I can even spell that right much less find a beneficial purpose for it in my tank.

Maybe these supplements really don't add much value to a reef tank but rather add value to the manufacturer's bottomline.

I think most of the trace elements are well represented in the salt mixes we use. In fact, many of them are represented at levels far, far in excess of NSW levels. After reading Shimek's analysis of 23 samples of water taken from 23 different reef tanks, I don't think the problem is a lack of any particular trace element, rather it is an excess of some of them.

[Bristle Worm]

Excellent and thorough response Ninong... Thank you!

Getting back into the reef hobby after a 2year break, I am trying to determine what the need-to-have test kits are to maintain a successful reef and therefore my questions have been directed on this line....

Basically I feel at this point the need-to-have test kits/apparatus to maintain a successful reef are:

Salinity meter
Thermometer
Ph Meter
TDS Meter
Calcium test kit
Hardness test kit

I think the nice-to have test kits are:
Nitrate/Nitrite
Phosphate
Chlorine
Ammonia
Magnesium

And the questionable
Copper
Strontium (the original subject of this thread)
ORP
and everything else................

[Reefland]

Hey Worm,

I would add Nitrate to the required list. This would be the first kit I grabbed if the appearance of our tank made me think something wasn't right.

[Bristle Worm]

Hey Reefland
Please feel free to call me Bristle but not worm, that is reserved for my more initimate aquaintenances.

Ok List revised for per your recommendation:

Salinity meter
Thermometer
Ph Meter
TDS Meter
Calcium test kit
Hardness test kit
Nitrate/Nitrite

I think the nice-to have test kits are:
Phosphate
Chlorine
Ammonia
Magnesium

And the questionable
Copper
Strontium (the original subject of this thread)
ORP
and everything else................

[Rook]

Quick question; How long are test kits good for? I have several Salifert test kits and they are getting old now but they have several tests left in them??

[Ninong]

Quick question; How long are test kits good for? I have several Salifert test kits and they are getting old now but they have several tests left in them??

Some Salifert test kits are good for several years, others are not. I once wanted to test my boron levels. I ordered a Salifert boron test kit but it didn't work because it was at least 6 years old! The online vendor insisted that they had just received it within the past few months from Salifert's main U.S. distributor. I was able to determine the age of the test kit only because I was able to find out exactly which year Salifert had changed their boron test kits to a newer version that had a different end color.

I contacted the president of Salifert and he promised to get me a replacement kit that was fresh. To make a long story reasonably short, he didn't fulfill his promise even though he repeated it three times over a period of a few months. The online vendor sent me a replacement Salifert boron test kit but it turned out to be another one that was more than six years old!!! That one was supposedly part of a new batch they had just received that was intended to replace their previous stock.

I was unable to acquire a fresh Salifert boron test kit after three or four months of effort, so I gave up. The president of Salifert never did send me the new boron test kit that he promised to send in two or three emails and two PMs. His final email to me was to the effect that if I was in need of the money he would be happy to wire it directly to my bank account if I would provide him with the routing numbers. The online vendor refunded my money and they also told me that they have never been able to get refunds or replacements for faulty test kits from that particular manufacturer.

Having said all that, I still use some Salifert test kits. I also use LaMotte test kits for calcium and alkalinity and I will try to find LaMotte kits to replace some of my Salifert kits if they are available. One good thing that came out of my correspondence with Salifert is that they began putting expiration dates on all of their test kits. They started doing this more than a year ago.

If you need to know if the reagents you have are still viable, you can post that question in Salifert's sponsor forum on Reef Central. You will need to post the batch numbers from each reagent. The president of Salifert will likely answer your questions either in that forum or by Reef Central PM to tell you if your reagents are still good. Some reagents have a shelf life of several years, others do not. If you are not already a member of Reef Central, you will have to register.

BTW, if you happen to come across a vendor selling a fresh boron test kit, please let me know. The only people that I know of with fresh boron test kits received them directly from the manufacturer in Holland. And I believe Salifert is only manufacturer making a hobby-priced boron test kit.

[Rook]

Thanks for the great response. I assume you use a mix of test kit companies, such as Salifert and Lamotte. How did you decide which to use?

[Ninong]

Thanks for the great response. I assume you use a mix of test kit companies, such as Salifert and Lamotte. How did you decide which to use?

I asked other hobbyists who seemed to know what they were doing which test kits they used. I found that test kits come in a very wide price range and that the cheapest ones are usually worthless. The consensus of opinion among people who actually know what's up is that Hach and LaMotte make the best test kits but that Salifert makes a reasonably good test kit for the money. I found out that some of them were paying the big bucks for Hach test kits but most were using LaMotte and Salifert. A lot depends on where you want to draw the line financially. For some test kits, the LaMotte version will be $22.99, the Salifert version will be $15.99 and the cheapy brand will be $9.99. With that sort of a price breakdown, I went for LaMotte.

If I remember correctly, I wasn't able to find some of the LaMotte test kits when I started up my tank and that's why I ended up with some Salifert test kits. I do recall seeing some test kits (probably Hach) that were something like $54 compared to a price range of $15 - $25 for the same thing in other brands and I'm sure I passed on those in favor of the $25 version.

I just checked Custom Aquatic's website to see what they were listing and I see that they are finally picturing the new version of Salifert's boron test kit, so maybe I'll order one. Again. And see if it works.

One nice thing about the LaMotte calcium and alkalinity test kits is that they sell refills that cost less because you aren't paying for the glass vials and titrators all over again, just the reagents. Oh, and LaMotte kits come in nice permanent blue plastic cases instead of cheapy thin cardboard boxes. I like my LaMotte calcium and alkalinity test kits and I will look around next time to see if I can find any other test kits by LaMotte before settling for Salifert. I don't think I'll go for anything more expensive than LaMotte unless I hit the lottery.

[zhenya]

I like my LaMotte calcium and alkalinity test kits and I will look around next time to see if I can find any other test kits by LaMotte before settling for Salifert. I don't think I'll go for anything more expensive than LaMotte unless I hit the lottery.

George,

They actually make pretty wide range of test kits, however, once you go past Ca and Alk kits they also get expensive. For example, their Iron test kit will run you $75.38, their Copper test kit is listed at $68.94, PO4-$68.78.
You can search them at www.aquaticeco.com but you'll need part number to search as they do not have ALL test kits listed on their site, I think only master kit by Azoo and something else. If you need those part numbers, I can give them to you as i have their BIG 2005 catalog.
Oh, forgot to list the price for the Ozone test kit - $89.92 and NO3(low level) is at $56.93. They also offer reagents on that website as well.

PS. Forgot to dd that I was looking at this test kit but I doubt it could be usefull for a reef tank. I got to search some more. ;)

[Ninong]

George,

They actually make pretty wide range of test kits, however, once you go past Ca and Alk kits they also get expensive.

Yes, that's why I decided to skip some of their more expensive test kits the first time around.

Their ammonia test kit (#3304) appears to be much more sensitive than Salifert's but the price is pretty steep and you very seldom need to test for ammonia anyway. If you're ammonia is high enough to be a problem, you will be able to use your eyes as the test kit and save a lot of money. Salifert's ammonia test kit measures 0.5 ppm and above and that's good enough for testing while you're curing live rock.

I guess you could get that expensive LaMotte ammonia test kit if you wanted to test your freshly made up saltwater for ammonia. You will probably measure something between 0.10-0.20 ppm total ammonia in your saltwater if you had a test kit capable of measurements that low.

I might consider getting LaMotte's nitrate test kit (#3319). I'm not sure some of their other test kits are sensitive enough to warrant the extra money. Look at the increments on their phosphate test kit for example.

PS. Forgot to dd that I was looking at this test kit but I doubt it could be usefull for a reef tank. I got to search some more. ;)

You can check it out on their website.

[Bristle Worm]

Thanks guys for all of the responses.....

I also found the following reef chemsitry article by Randy Holmes Farley to be helpful as well:

http://reefkeeping.com/issues/2004-05/rhf/index.htm

Keep on reefing!!!

[Ninong]

Thanks guys for all of the responses.....

I also found the following reef chemsitry article by Randy Holmes Farley to be helpful as well:

http://reefkeeping.com/issues/2004-05/rhf/index.htm

Keep on reefing!!!

Thanks for posting a link to that article. I must have missed that one. As usual, Randy's advice is right on!