Phosphates and Meters

[lpsluver]

I have zero phosphates and zero nitrates, by new Salifert kits, but yet I still have HA issues. Will a Hanna or Milwaukee Phosphate meter show measurable results for phosphates or do they measure the same species and what I am seeing is the HA using it as a food source before it can be measured by any system?

In other words is the purchase of a meter even worth it?

I do bi-weekly water changes, feed rinsed mysis every other day, have a good skimmer and run a Phosban reactor. (This is in a RSM 34 gallon system with a 19 gallon sump.)

[Randy Holmes-Farley]

The idea is not to get a new meter, or even a more accurate measure of phosphate. The idea is to intercept the phosphate before the algae gets it. Algae can keep phosphate levels low just by sucking it up. That's how growing macroalgae works. Microalgae can do the same thing.

So look to intercept the phosphate, and you'll win the hair algae battle. :)

[lpsluver]

Randy,

I understand what you are saying. But my question is more of one in which I'd like to establish where I am so I know how far I need to go. I want to be able to do this empirically not visually. Even going the vodka dosing route the suggestion is to know what the phosphates and nitrates are before you start the dosing regimen.

I've not had any luck in the past with intentionally growing Chaeto (in a fuge) but I can grow the heck out of HA and caulerpa in my display.

I've been at this hobby long enough to know about nutrient export but what I am doing now is not working and I'd like to know what my starting point is. Will a meter give me a reliable reading or do they measure the same species as the test kits?

[bertoni]

The meters used by hobbyists aren't rated to be any more accurate than test kits, and might be less accurate. I believe the meters all measure orthophosphate. I believe there are some test kits to measure total phosphorus, but they are harder to use.

[xenon]

If the algae is eating up all the phosphates how can you possibly test for it?

[Randy Holmes-Farley]

Right. Whether the actual value right now is 0.02 or 0.000000001 ppm, it makes no difference. If algae is thriving, there necessarily is a lot of phosphate going into it. You are not testing to find out if there is available phosphate. There absolutely has to be.

That said, the one place I do think testing is useful is if you do have a lot of measurable phosphate, with or without algae. Then you can use the measurement to gauge the degree of the problem, how fast to swap out some GFO, etc.

[lpsluver]

Okay...So I am surmising (in a left-handed kind of way, and I am left handed:p ) that my phosphate is "under control". Meaning it is being used by my HA as quickly as it is generated. Now I just need to get something else to use it before the HA does in order to reduce/eliminate the HA and find the source.

I'm also surmising that if you have measurable phosphate you are currently battling a nasty algae problem or you soon could be if you do not get it under control.

Randy thanks for your help.

[Randy Holmes-Farley]

:thumbsup: I'm left handed too.

yes, that summary sounds good.

Good luck. :)

[3fins]

Please tell me how u fixed ur HA problem =/ im having problems with it to : (

[Randy Holmes-Farley]

The easiest way to deal with hair algae is to reduce the nutrients available to it, especially phosphate, and using a GFO type of phosphate binder is the best short term solution, IMO.

[allen64086]

I had a bad hair algae problem. My phosphates were high...about 1.00. I tried water changes, reducing feeding, reducing light, and even changed light bulbs with no luck. Finally, I used phosphate sponge to reduce my phosphates. After that, I still had a HA issue. So I put a Seahare in the tank. It ate all the hair algae. Since then, I have not had any issues even though my phosphates are still reading about 0.25-0.375. My corals are doing great and the tank looks good. I wish I would have known about the Seahare from the start. I am also running a phosban reactor and chemi-pure, which may have helped as well.

[Dejavu]

<a href=showthread.php?s=&postid=13469892#post13469892 target=_blank>Originally posted</a> by bertoni
The meters used by hobbyists aren't rated to be any more accurate than test kits, and might be less accurate. I believe the meters all measure orthophosphate. I believe there are some test kits to measure total phosphorus, but they are harder to use.

IMO a meter is more accurate than any test kit. While both only measure for orthophosphate, test kits color indicators do not have the sensitivity that a spectophometer has.

I don't believe there are any hobbyist test kits that measure total phosphorus. In fact all hobbyist test kits that I know of only measure for orthophosphate.

Acid hydrolysis at boiling- water temps will convert organic phosphorus into orthophosphate. Without boiling in acid, dissolved and particulate condensed phosphates will not dissolve to ortho.

I don't know of any hobbyist test kit that requires boiling. Hach does have a few different methods that are easy to use. Simply add a pillow, heat in their reactor,
read with spectophometer.

[Randy Holmes-Farley]

IMO a meter is more accurate than any test kit.

It may be, but have you seen any actual data comparing it to the Hach PO-19 test kit?

In fact all hobbyist test kits that I know of only measure for orthophosphate.

If you do not count the Hach total phosphorus kit (not their photometer methods, but test kit PO-24) among hobby kits, then yes, I agree, but the same applies to hobby meters.

[Dejavu]

If you do not count the Hach total phosphorus kit (not their photometer methods, but test kit PO-24) among hobby kits, then yes, I agree, but the same applies to hobby meters.

I know Hach has many different test kits out and as a company they are very innovative. In fact we use Hach 8190 test for total phosphorus at many work. Does the PO-24 call for digestion? If not how are they removing the oraganic from the phosphorus or polyphosphorus?

[Randy Holmes-Farley]

Yes, the PO-24 kit has a digestion step in it. :)