FE test that does work??? MAYBE I FOUND ONE!

[fedge]

This is supposed to be a new test kit from Red Sea ( I tend to trust their stuff a little more than others).

Its that "plant lab" kit with co2 and Fe test kits...

I have been having problems with my plants see post

http://www.plantedtank.net/forums/showthread.php?t=9116

So I mega dosed the PMDD to my 20L and today I thought I would test for FE.. it read 0.5!!!! It was always 0 before (at least when i finially got the plants established.. when i had tons of algae it read 0.1 and 0.2 never higher)...

anyone else have this kit????

[macbrush]

I use Sera and JBL, and their results are always consistent to each other, and reasonable too, namely, I always try to get the reading to between 0.5 and 1, and when it goes higher, thread algae would attack.

[zapus]

Don't have the kit, but have always been curious about the CO2 test in the red sea plant kit, does it work the same old way or have they come up with an independent method to determine CO2 levels?

[fedge]

Co2 test is a titration test... add one chem... then you add drops of another..till the color shifts. each drop is approx. 2ppm of co2. It is pretty dead on with the ph/kh ratio. +/- 2ppm usually.

[malkore]

the red sea 'plant care test lab' is the iron test kit that we all see, and that we know isn't very useful.

I'm sure the CO2 kit works, but if it's dead accurate with the chart/table, why spend money on another test kit. As for the Iron test kit, i don't trust it.

[fedge]

well it is what I bought BEFORE i knew that a lot of people don't find them reliable.

[zapus]

Originally Posted by malkore

[snip]I'm sure the CO2 kit works, but if it's dead accurate with the chart/table, why spend money on another test kit.

I was thinking that it might be an independent way to verify CO2 content, especially if you were worried about organic acids or phosphates throwing off the pH/kH calculation. See http://www.plantedtank.net/forums/showthread.php?t=9132 as an example. If the test works via an acid/base titration, however, it may suffer from the same flaws and I must admit that Rex's solution is both simple and elegant.

[putty]

I'm still waiting for Rex to pipe up in here.

[Rex Grigg]

Originally Posted by putty

I'm still waiting for Rex to pipe up in here.

About what? I don't rely on ANY iron test. And I use the pH/kH method to determine my CO2 levels.

[glass-gardens.com]

So how do you determine your iron levels?

[putty]

About how Fe tests don't work.

[fedge]

rex?
..... I know a lot of planted tank people think it is a waste of time to have a FE test kit.. but im not convinced entirely yet....

Some "experts" are just experts cause they have kept tanks for years.. but they are not chemical engineers. Maybe if you could shoo me off to a site that proves that these test kits are completely bogus I would tend to agree.

[mpb]

This is my theory about iron test kits:

According to Karen Randall:
“At the same time, do not be fooled into overdosing your tank if you do not get an iron reading in the first few weeks of supplementation. Plants can store quite a bit of iron. If they have been iron deprived for a length of time, they will suck up all available iron until they have stored as much as they can.”

I think this is one of the reasons that people do no trust Iron test kits. You can be adding iron and test results show that there is no iron. Plants a sucking up all the iron they can. On the other hand you may not be adding iron and the plants are doing just great. This is when plants can outcompete algae. If there is no iron on the water column there will be no iron for algae and plants will be using the iron on their reserves. The goal is to have zero iron on the water column and plenty of iron on the plants reserves. You should add iron only when plants starting running out of iron, so they will consume the entire iron on the water quickly. As experienced hobbyist, you know how plants are starting to show iron deficiency symptoms and you correct it. For you, the iron test kit has no use as iron on the water column should be always zero.

So, to test an iron test kit, do what Rex suggests: test it in a bucket.

[malkore]

AFAIK, the CO2 test kit is an acid titration, so it's skewed exactly the same way the pH/Kh chart is skewed if there's high phosphates, etc.

As for anyone who's paranoid about Iron levels...if you're that paranoid, but a LaMotte kit and let us know how you like it. I'm not sure it reads Flourish Iron levels correctly though.

[Rex Grigg]

Tom Barr has said that even the LaMotte Iron test kit is not that reliable. IMHO too many consumer level iron test kits are greatly affected by pH, hardness and temperature. Also we are generally testing for iron levels that are very close to the ability of these test kits. I have not tested for iron in my tanks for a couple of years. And I don't even regularly add iron any more. If plants start showing signs of iron deficiency then I add some.