Reading Test Kits

[Angry_Platy]

I have been using the E.I. method for a few weeks now. Great plant growth, little algae growth and fish still healthy....

BUT....

I have trouble reading the nitrate test....which is important for E.I. I am using the Hagen brand which basically has different shades of pink....

I know the only way I am going to be able to do it properly is to take known concentrations of nitrate (makde from stock) and take photos under the same lighting conditions and comparing these to my tank water.....make sense?

Its just confusing me at the moment.

Does anyone have any reliable way of reading test kits?

 

[houndour]

nope sorry. I too have the same problem deciding which colour its nearer to. I particularly have problems with the hagen phosphate and iron kits. I find if you hold the tube right against the chart (the white bit to the side) its different to if you hold it not quite touching it. I think the instructions say to read them with light behind it. I just don't know really! testing a known sample is a good idea though.

 

[Bloo]

NitrAtes are notoriously difficult to read. I find anything above 40 all look more or less the same to me (actually make that 20)
I've tried a few different tests too, but much of a muchness in them.
I read my tests by holding them slightly away from the white bit on the card - next to the colour range.

 

[zig]

I have the same problem, but i only use my nitrate kit as a guide when ever i use it, once you know you have dosed enough there is really no need for test kits anyway, i really only use them when i add or remove any plants to the tank.

i maintain my nitrate levels at around 15ppm or there abouts, when i do my water change i would have about 5-8ppm left in the tank so i add 10ppm to bring me back above 15ppm, 2 days later i add 5ppm and before the end of the week i add another 5ppm, this keeps me at around 15ppm all week.

Now each tank is different the uptake rate will vary for each one, my point is that i dont test at all because i know i have added enough in the first place, i probably do a nitrate test maybe once every 2-3 weeks more out of curiousity than anything else and it usually (hard to read ) gives me an indication of where the levels are at but i could nearly guess depending if i have added nitrate that day or not.

I Just use them as a guide and i make sure i dose enough in the first place.

 

[Angry_Platy]

I am going to buy a new nitrate test kit this weekend. I just tested known concentrations based on the stock solutions I made up and according to that I have nitrates of around 40....I must be overdosing.....well...based on what I THOUGHT were my nitrate values.

Now I am worried about algae....

Should I really be stressing about nitrate anyways?

I am thinking of not adding any for the next few days to give the plants a chance to use some of the excess. Would this be bad?

 

[George Farmer]

I personally don't worry too much about specific levels - as long as it's above 5ppm and below 30ppm. Mine looks about 20ppm most of the time, but as you say the pinks are quite ambiguous in the Hagen (Nutrafin) kits.

Nitrate kits are notoriously unreliable anyway. It is more accurate to rely on the calculations when dosing. As you long as have a basic idea of your uptake rate you will be fine.