Ammonia in my ferts solution?

[Jose]

Hi everyone.

First of all I am aware of the bad reputation test kits have around here but I am still going to ask.

I ran an ammonia test with clean water (no ammonia as tested before) and added two drops of a fertilizer mix solution that I prepared for my aquariums. The test came out positive for ammonia.

The solution had K3PO4, KNO3, CaCL2 and MnSO4 and tap water that reads 0 ammonia.

Does anybody know if some of the KNO3 can go back to NH4/NH3 form? I bought food grade KNO3 (99% purity)
Maybe some of the components are reacting to give a false reading?
The reading was strong enough colour as to be worried. What if im adding ammonia to my tanks together with the other nutrients?

Any help is apreciated.

Thanks!

 

[GreenNeedle]

I would dilute the test down further and test again. After all you are going to be dosing minimal amounts compared to the volume of the tank water.

 

[Jose]

Yes thats right. The tank water doesnt test positive but with test kits you never know right. Ill do that SuperColey1, but if it tests positive and its not a reaction of some chemical in the ferts then I am adding a bit of ammonia.

Does anyone around here prepare ferts solutions? Has any one tested them?

I might just add the dry salts to make sure.

 

[GreenNeedle]

In all honesty if you are adding such a small amount of something as in 5mls of fert in 125 litres of water then unless it is purely ammonia that is being added I wouldn't think it would register at all. I doubt anyone tests their solutions because of the amount of dilution here. The only problem would really be if it was in the tap water and therefore adding a much higher percentage 10%-50% @ water changes would be a problem.

Are you sure it is ammonia? Could be ammonium. I remember people used to freak out when they had ammonia reading when dosing Tropica TPN+ which was because they use(d) ammonium nitrate as their N source.

 

[Jose]

Its NH3/NH4. The test kit reads both but it doesnt make much of a difference to me. I didnt add any commercial ferts just food grade powders.

I am pretty sure there is non in my tap water.

 

[ian_m]

I have a feeling the standard ammonia tests are affected by chloride ions, also nitrate tests as well, which one reason why you shouldn't use home test kits on tank water.

Could you repeat the test on your solution with out the CaCl before you put the test kit in the bin ?😀

 

[Jose]

Haha yes that sounds like the most plausible cause (the CL- from the CaCl2). But I am afraid its already dissolved in the solution. So no worries I not throwing away the ferts. The next time when I prepare the solution again Ill just test before putting the CaCl2 in just for the fun of it.

Thanks every1.

By the way I can confirm your suspicion on Cl and ammonia test kits pretty easily. Just dissolve some CaCl2 in water and test. But I havnt really got any doubts on the cause now.

 

[ian_m]

Just dissolve some CaCl2 in water and test

I think its the Cl that alters the NH3 reading (up or down ??) rather than reading it direct. I thought it was down, but tests indicated ammonia when you had Cl present. More likely the presence of Cl & NO3 is causing the false reading.

 

[Jose]

I get a green colour so thats like 4ppm ammonia where there should be none. Ill run a test when I get home to figure out which ions effect the ammonia reading of the appi test kit. I will try K3PO4, KNO3, CaCl2 and MgSO4 seperately of course. Many people in other forums have had a very slight ammonia reading in a tank that shouldnt have it.

Also it all makes sense now. The kit has two charts, one for freshwater and the other for salt water. What is there in salt water more than in fresh? Yes ions. Is there more Cl- in saltwater? I would think so...The chart for salt water reads a 0 ppm at a darker colour meaning there is a false reading in clean ammonia-less saltwater.

 

[dagtveit]

this is from http://answers.seneye.com/en/water_...t/NH4_and_NH3_calculations_and_look_up_tables which sells a digital measuring device. but i think the information is till good.

mmonia test kits mostly measure TAN especially if they are marked as an NH3/NH4 test kit. The measurement is done by changing the pH of the water sample; you may have noticed how ammonia test kits normally have a small bottle marked harmfull corrosive. Using NH4 temperature and pH to accuratly work out how much NH3 is present is very very difficult click here to find out why.

Using traditional methods free ammonia (NH3) is very hard to measure so normally people measure non-toxic ammonium (NH4) in the aquarium and pond and use this as a guide to safe levels of NH3. In true terms NH4 is a nontoxic substance in the aquarium, however due to the equilibrium which occurs between NH3 / NH4 at a given pH andtemperature it is better to measure NH4 as an indicator of NH3 than nothing at all. Interpretation of NH4 to estimate NH3 is most often done by a chart supplied with the test kit or by a calculation online. If you are using these methods as a guide to NH3 in the aquarium do not expect it to exactly match your seneye. All measurements devices and test kits will have some error and when you are using 3 different measurements in a calculation a small inaccuracy on each can heavily skew the result. The calculations and look up tables do not take into account ionic strength or air pressure which can both influence the NH3 / NH4 balance.

A seneye device will measure deadly NH3 directly, if you have a seneye reef device you will also get an NH4 widget on your seneye.me dashboard. To provide this we do a calculation derived from the known pH, temp and NH3 reported by your seneye device. For the same reasons stated above it should only be used as a rough guide.

Please note: Ammonia and ammonium (NH3+NH4) together are usually described as TAN or total ammonia nitrogen. Often test kits measure TAN not NH4 or NH3, this can make accurate NH3 calculations even harder.