Hanna Photometer

[frank40]

I recently had phos issues because of my RO and in my search to find out my real phos levels, i found out that my Hanna meter is +.03 off. i found this out from testing it with distilled water. i then opened up the manual to the Hanna and it says it has a +/- .04 variance. i just found that disturbing that even a supposedly high-end tool is still off and a friend of mine has the Hach meter which cost 5x the Hanna and it has a +/-.05 variance also.

[kaskiles]

I agree with you that I would like better accuracy for the price, but at least it can tell you <= .04, and it is repeatable (no visual color charts).

Even worse is that it only measures inorganic phosphorous.

Just think of all that dissolved organic phosphorous floating around in there; feeding malicious algae and inhibiting coral calcification...

[losthere]

I agree with you that I would like better accuracy for the price, but at least it can tell you <= .04, and it is repeatable (no visual color charts).

Even worse is that it only measures inorganic phosphorous.

Just think of all that dissolved organic phosphorous floating around in there; feeding malicious algae and inhibiting coral calcification...

With that info. would it be recommended to buy one? I have been looking into it but havent purchased it yet. I have been using the Salifert test kit, but have read that they are inaccurate. Should I save my money and just keep using them?

[kaskiles]

I would recommend that you save your money, unless:
1. You just like gadgets.
2. You have a color blindness issue with that light shade of blue (not even sure if people can have trouble with that color...).

[frank40]

the Hanna meter is widely accepted as the standard for our hobby, the only test kit that comes close is the D&D kit and that is around $80. all other titration kits do not register to the level we are looking for.......if you are getting a reading from a titration kit, you are in trouble already :eek2:

[CoralMonkey]

the Hanna meter is widely accepted as the standard for our hobby, the only test kit that comes close is the D&D kit and that is around $80. all other titration kits do not register to the level we are looking for.......if you are getting a reading from a titration kit, you are in trouble already :eek2:

I think you are right, becuase my Elos kt always reads 0... but there is no way it is really at 0. This is an interesting thread, because I was also looking into getting a hanna photometer. +/- .04 is pretty significant when measuring phosphate, isnt it?

[vegaskid11]

Last night I measured po4 with my Elos kit for fun and there was no color change at all. The liquid was perfectly clear. The lowest color square (0) had the slightest blue tint yet my test was perfectly clear. I then used my hannah meter and got a reading of .05

[StrategicReef]

I have been wanting to get one but still couldn't due to the price tag. my ELOS kit has been useless. I had people who own the hanna and told me I don't really NEED it.
So it's a "want", not a "need"

It may be good to tell if the GFO is exhausted..

So what is the verdict?

[dnov99]

I have used salifert in the past, and the test sample looked clear as can be, and then when tested with Hanna they were still between .10 and .15. I like the assurance of having the Hanna meter. I think it is more of a must for SPS keepers as they are more affected by high PO4.

[frank40]

i prefer having the Hanna than not having it, i to used the Elos and never get a reading from it.....so according to Elos i would never change out my Rowaphos. at least with the Hanna i have an idea of when i need to swap out the GFO.

[vegaskid11]

[QUOTE=StrategicReef;16481853]It may be good to tell if the GFO is exhausted..[QUOTE]

This is my main use of the meter. I measure tank water then I measure GFO effluent. When they match I know its been exausted.

[chuckreef]

First, there are plenty of succesful reefkeepers without one.

I think you can rely on the tank as an indicator. If a little patch of cyano or grren hair algae and you know its time to run some proshpate remover. I never leave GFO or Alumina oxide in place for more than a week. When using phospate remover for algae contriol I run three to four days and then replace it with fresh media unitl the tank clears.

If I see neither algae or cyano present, I run GFO for three days once every three to four months just as maintenance.

I beleive all of these media become biologically active and can do more harm than good (i.e, can increase N- wastes) when left in place.

I beleive the GFO absorbs PO4 exponenetially for the first 24 hours to 48 hours after which the PO4 absorption rate drops to so low that its doing little more than nothing. (I think the assorption rate is almost first rate kinetics after a day or two in the system after the intial high rate of adsorption, and assuming the PO4 level has already been driven down low the amount of addional PO4 removed over a long time is probaly insignificant as compared to the biological activity on the media surface.)

So, my advice is use the phoshapte media when needed, change it often (especially the GFO), and skip the meter unless you need to track down a source or are doing some sort of experimenting with your system.

[ryshark]

[QUOTE=StrategicReef;16481853]It may be good to tell if the GFO is exhausted..[QUOTE]

This is my main use of the meter. I measure tank water then I measure GFO effluent. When they match I know its been exausted.

Thats a good idea, and who knows, this method would probably save us money on GFO, which is pretty expensive.

[dwhanc00]

What would be considered a good price for one?

[frank40]

Every GFO has its own max absorption levels so it depends on the levels within a tank to dictate when to change out GFO. if your levels are high to start with, then replacing the GFO frequently is the only way to get the phos down but if your levels are low to start then you will not need to swap out GFO as much because it hasn't reached its max absorption level.

[StrategicReef]

So the Hanna doesn't measure organic phosphates, which is the phosphate resulting from feeding fishes and bioload, isn't this phosphate the one we want to know?