ammonia and nitrite

[Airborne 82nd]

Ok I don't have a issue with these but I like to read. I keep seeing some people say to add your ammonia result to your nitrite result. If the combined total is more than 0.5ppm then change enough water to bring it below 0.5ppm combined. Why add these two together instead of just using the readings from the test kit on there own?

 

[Andy Sager]

Because toxicity levels can be over the deadly level if you do them separately.

This is the nitrogen cycle on a graph so you can see that ammonia and nitrite can both be present in an uncycled tank.

 

[Airborne 82nd]

So if my tank is cycled I don't need to do this?

 

[Andy Sager]

So if my tank is cycled I don't need to do this?

Correct. If your tank is cycled and you see an ammonia reading, 1st confirm your result with either a second test or someone else testing the water and 2nd, if it's confirmed, do a water change and start figuring out why it was there. ( i.e. I added more fish, I overcleaned the tank, I thought I added dechlorinator but it was actually Ammonia , etc. )

 

[Airborne 82nd]

I thought I added dechlorinator but it was actually Ammonia , etc. )
Hey come on that is why I tossed the Tims

 

[Aiken Drum]

So if my tank is cycled I don't need to do this?

If your tank is cycled you wont see ammonia or nitrite. You have enough of those microbes to consume ammonia and nitrite in short order. If either shows up on your testing when it previously wasnt, either something happened to kill off those microbes or more ammonia got into the water than normal and you should investigate what happened. The ammonia and nitrite levels may not be a problem, but they are indicating something else that may need to be dealt with.

Ammonia is toxic once it gets to a certain level and nitrite is also toxic once it gets to a certain. If you have both then they are more toxic, so when you have no nitrite the ammonia can be a little higher and vice versa. Different people have different ways of doing things. Adding them together is my way and gives a little wiggle room to avoid having to do more than necessary water changes while cycling. Its common to see people say test for both and if you see any ammonia or nitrite at all then change water until they are both zero. Thats not wrong, but IMO its a little excessive if you understand ammonia and nitrite toxicity.

in reality its more complex than absolute levels though. Adding ammonia and nitrite together and keeping it below 0.5ppm combined gives you a safety net thats easy to understand. In reality ammonia is more toxic at high pH and nitrite is more toxic at lower pH. In very acidic water ammonia can get very "off the testing chart" high and remain non toxic. But people asking questions about cycling are usually beginners and keeping ammonia + nitrite combined below 0.5ppm is easier to understand than keep ammonia below X if your pH is Y and keep nitrite below A if your pH is B.

Here is a good thread on ammonia toxicity if you are interested.

Your Guide to Ammonia Toxicity

*WARNING* This guide is intended to give a better understanding of Ammonia toxicity and is not intended to diagnose or treat any problems. Please use this information wisely. *WARNING* Ammonia. It's bad. I think even the most novice fishkeeper understands this concept. It's a common idea that...

www.aquariumadvice.com

 

[Airborne 82nd]

Aiken Thank you I read that thread back in Jan. when I set up my tank I like the charts and the way it shows how ph and temp play a part in how toxic the ammonia really is. My tank cycled in March just before I got my Oscar I stopped using Dr. Tims. Everything has been doing fine. No ammonia or nitrItes and when nitrAtes get about 20ppm I clean up the water and substrate. I just brought this up because I didn't know why you would add them up It didn't click in my brain that it was only talking about a tank that was not cycled yet. I want to thank you and Andy for all the great post you have written I've learned a lot from them.

I also read this one. Guide to Starting a Freshwater Aquarium​

Airborne

 

[Andy Sager]

I thought I added dechlorinator but it was actually Ammonia , etc. )
Hey come on that is why I tossed the Tims

What can I say, accidents happen.
Just to prove we all have them, it happened to me too. I used to drink a lot of coffee at work. In one shop I developed a marine fish diet that was better than anything on the market at the time. The ingredients would make any seafood lover drool. ( ie shrimp, fish, clams, scallops, fish eggs, lobster eggs, spinach, and more). It was a frozen food so I would take out a chunk and thaw it in a styrofoam cup up on a top shelf with some saltwater from a tank. One day, I was talking with a customer while thawing the food and had placed my coffee cup on the lower shelf. I needed a drink and grabbed what I thought was my coffee cup and took a big swig. I was wrong!!!! It tasted good but was very salty. So you see, it happens to the best of us.