Are phosphate kits junk?

[poppin_fresh]

I posted this in the Salifert forum, but no one has responded to it.

I read a post that said phosphate kits (in general) are a waste of money because they are so inaccurate. I was planning on getting one this weekend and starting to test for it. I am pretty sure phosphates are responsible for the algea problems I've been having. Should I spend the money?

 

[Danster]

IMO you should have a phospate kit (Salifert) and check it often. Phosphates are probably the number one problem when it comes to algea blooms and nobody wants that.

 

[Fatboy]

I'm using a Tunze phosphate kit and I find it very accurate (much more than the salifert.......) and easier to read.

Now I'm buying a Hanna colormeter to make samples even more accurate.

 

[Newreeflady]

Fatboy, you've tried both kits with same water and got better results with the Tunze kit? Just verifying.

-A

 

[Randy Holmes-Farley]

I'm sure Habib (owner of Salifert) will get to your question in his forum.

That said, whether you need a phosphate kit is up to you. If the tank is looking fine and things are growing to your satisfaction, there is no need to test for phosphate.

I use a Hach kit (which I believe is quite reliable within its intended range), but it typically reads very little phosphate in my system, so it is not a routine test or necessary test.

IF, however, algae is a big problem, SPS and other hard corals are not growing or die, or if you have other reason to believe that you have elevated phosphate, then by all means get a good phosphate kit to gauge the magnitude of the problem.

This article has more on phosphate:

Phosphorus: Algaeââ"šÂ¬Ã¢"žÂ¢s Best Friend
http://www.advancedaquarist.com/issues/sept2002/chem.htm


and these may be useful:

Reef Aquarium Water Parameters
http://www.reefkeeping.com/issues/2004-05/rhf/index.htm

Iron Oxide Hydroxide (GFO) Phosphate Binders
http://reefkeeping.com/issues/2004-11/rhf/index.htm

 

[Fatboy]

<a href=showthread.php?s=&postid=7019071#post7019071 target=_blank>Originally posted</a> by Newreeflady
Fatboy, you've tried both kits with same water and got better results with the Tunze kit? Just verifying.

-A

Newreeflady,

I just realized that I made a big mistake....... the Tunze kit I'm using is for Nitrates and for Phosphates I'm using a Deltec kit.

The Deltec Phosphate kit is so much easier to read....... and from what I have compared to the Hanna colormeter, the readings are very close to each other.

I have used Salifert and Deltec side by side.... and the Deltec one is far easier to read. Almost no room for interpretation mistakes.

Even that salifert kits are OK in my opinion, I think that they are extremelly hard to read when you compare it to the system used by Deltec and Tunze. The blue color is too difficult to match sometimes and there is ample room for mistake......

 

[Randy Holmes-Farley]

Now I'm buying a Hanna colormeter to make samples even more accurate.

Aside from it being more high tech, do you have reason to believe it is more "accurate"?

 

[kevin2000]

My 02

The primary problem with phosphate test kits is that they are limited in what phosphates they can register and that inorganic phosphates are quickly consumed/sequestered by algae/bacteria etc. You will see plenty of posts where people have obviously phosphate laden tanks where there phosphate test kits show zero phosphates. Many would suggest that the best use of a phosphate test kit is to determine whether the water your placing into your tank has phosphates ... once the waters in your tank the test kits become more suspect.

 

[poppin_fresh]

Randy,
I started reading the article on phosphorus and now I really believe I have problem. Not only have I had really bad HA problems, but my tank has never grown coralline very well. Its been a year and very little of my base rock has colored. This is while using Oceanic salt that has my Ca. at over 520 on my Salifert kit. I am assuming the phosphates are causing a lot of my problems.

 

[Newreeflady]

Hi, Fatboy. Thanks for the help, I think i'll stick with the Salifert kit, though. I can't really afford the Deltec or Colorimeter.


-A

 

[Fatboy]

<a href=showthread.php?s=&postid=7022696#post7022696 target=_blank>Originally posted</a> by Randy Holmes-Farley
Now I'm buying a Hanna colormeter to make samples even more accurate.

Aside from it being more high tech, do you have reason to believe it is more "accurate"?

Randy,

Maybe the reactives are the same, but with a colormeter at least I'm not subject to trying to determine which color I got. Many times the macthing depends under which light you are making the comparison and I want to rule out that.

In summary, maybe the results are going to be the same....... the difference will be at the way those results are interpreted.


Newreeflady,

I can't afford the Deltec test in the US either and that is why I buy them in Europe. You can get the same test for less than half of the money.......

 

[Randy Holmes-Farley]

I am assuming the phosphates are causing a lot of my problems.

Even without a test, that is a logical assumption, and treating with something like GFO may be a good way to go.

In summary, maybe the results are going to be the same....... the difference will be at the way those results are interpreted.

Could be. Or maybe the results will be less accurate. I have no reason to think that to be true, but I also have no reason to think it isn't.

 

[Nathan]

Is it possible to have lots of problem micro algae (green film on the glass) and to have the test kit (Salifert) read almost zero?

That's what I have. Why is this?

-Nathan

 

[Habib]

<a href=showthread.php?s=&postid=7031173#post7031173 target=_blank>Originally posted</a> by Nathan
Is it possible to have lots of problem micro algae (green film on the glass) and to have the test kit (Salifert) read almost zero?

That's what I have. Why is this?

-Nathan

Algae can bloom at a very low phosphate concentration.

Usually there is also plenty of ammonia or other nitrogen source available in the water which allows algae to grow.

One can have a tank with very high phosphate concentration but no algae growth if a nitrogen source such as ammonia is missing.

 

[Nathan]

Could cyanobacteria be producing enough nitrogen based fertilizer for the micro algae? I have quite a bit of cyano on my sand.

-Nathan

 

[Randy Holmes-Farley]

Is it possible to have lots of problem micro algae (green film on the glass) and to have the test kit (Salifert) read almost zero?

That's what I have. Why is this?

Absolutely. That's the whole premise of using macroalgae: have enough algae growing of any type, and it consumes the available nutrients.

I doubt the cyano is producing much fixed nitrogen that it releases to the water relative to the large nitrogen inputs from foods.