Liquid Ammonia Test
 

I had my water tested at petsmart on friday and my ammonia was .5. I had let the water go a little longer than usual between changes, so I wrote it off. I tested again a few hours after a water change where I took out 75% of the water and it was still .5. I tested again 24 hours later out of curiosity and it tested the same. Following a 50% water change it still tested the same. I finally got smart and tested the water straight out of the tap and found the source. If my water tests at .5 out of the tap (likely because of chloramines) and I use stresscoat that means that .5 is neutralized correct? Does that mean that for my ammonia to be high enough for a water change it would read .75 on the test?

Using a conditioner that handles ammonia (like StressCoat) at water changes will deal with the initial increase in ammonia (from the tap water). However, conditioners only work so long.

Most ammonia detox products render the ammonia relatively harmless by changing it to ammonium. Test kits read ammonia/ammonium as "ammonia" so the API test for instance will still show "ammonia" whether it is ammonia or ammonium. Nitrifying bacteria will use ammonia or ammonium, whichever is present. Live plants grab ammonium as their preferred source of nitrogen.

So what all this means is that the initial sudden influx of toxic ammonia in the tap water will be neutralized by the conditioner, and then used by bacteria/plants. As the ammonia in the tap water is relatively minimal at .5, there should not be a problem in the aquarium.

Byron.

Thanks Byron. My nitrites and nitrates were zero does that mean it did cycle on its own? Petsmart didn't have the corkscrew val you recommended :(

I was assuming this tank was already cycled, and this ammonia issue was post-cycling. If this is the case, then you might not see any nitrite/nitrate change due to what I wrote previously.

But if this is a new tank cycling, that is different. Are there live plants in the tank now?

Yes there are live plants and the tank has been set up and populated since the first week of February. It just hasn't been tested until now. I saw what I believed was a bacterial bloom but didn't know for sure.

No problem then, in my view. It will work as I initially laid out. Having live plants means you would not see nitrite or nitrate rise because the additional ammonia/ammonium will be grabbed by the plants, with help from the bacteria but this is probably insignificant and not sufficient to cause noticeable [measurable with our test kits] increases in nitrite or nitrate.

Am I correct in thinking that the ammonia test doesn't matter unless it goes over .5?

To answer this, I will back up a bit, so there is no misunderstanding by other members who may be reading this and jumping to the wrong conclusion.

Ammonia and nitrite should never read above zero in a cycled and established aquarium. However, when ammonia (or nitrite) is entering the system via water changes, that is a temporary influx of whichever and this should be handled by a suitable water conditioner. Provided the influx of ammonia/nitrite is relatively minimal, the system (through the plants and/or bacteria) will catch up by the time the conditioner has lost its ability to detoxify [usually 24 hours].

A couple days after the water change a test should indicate zero ammonia (or nitrite) because by then the slight influx would have been handled by the plants/bacteria. If not, there would seem to be a source within the aquarium, and this should be investigated.

With respect to your test, if the reading indicates ammonia above 0 you must consider the probabilities: taken the same day as the water change should mean the "ammonia" is ammonium, so no issue. Taken 2 days later, it may mean problems.

Byron.

So I was testing too soon after the water change?

I would expect so.