Need Advice Regarding Nitrates And Now Slight Ammonia

[xgillian89x]

My tank has been cycled for a few weeks now and the last fish were added 2 weeks ago. I checked water on Thursday with my new api test kit and readings were ammonia 0, nitrite, 0, nitrates between 10-20. So I did a water change. Found a dead fish this morning so I checked the water and I have 0 nitrates and between 0-0.25 ammonia. It's not fully green but there is a slight green tint. It not as dark as 0.25. I'm not really sure what to do, can anyone advise me? Thanks.

 

[Ninjouzata]

I'd do another water change. How did you cycle the tank? What dechlorinator do you use?

 

[xgillian89x]

I bought the tank from someone and tested his water and it was all fine so used his filter media. I used pure ammonia and it was going from 3 ppm to 0ppm in a few hours. I did it a few times and all parameters were fine so I added fish and everything was fine until I did the water change the other day. How much of a water change would you recommend?

 

[Ninjouzata]

What dechlorinator do you use? I'm wondering because some of them can cause false ammonia readings on API test kit. What test kit do you have?
 
Can you give a list of the fish in your tank?
 
Maybe a 50%? You may not actually need to do one if it is false but better safe than sorry.
 
The 10-20 nitrates is perfectly fine btw

 

[daizeUK]

Some water conditioners can cause a false ammonia tinge (e.g. Seachem Prime).
Also test kits can be somewhat inaccurate.  I wouldn't be overly worried about a 0-0.25 reading.

 

[xgillian89x]

Is aqua safe not a dechlorinator? I'm pretty sure that's what we use. And I have the api test kit.
5 platys, 4 baby angelfish, 2 pearl gourami, 9 lemon tetra, 6 corys and a bristlenose plec. The tank is a 190 juwel trigon.
What about the no nitrates?
I've never had problems before, all my other tanks have been once it's cycled it's cycled, no ammonia or nitrites to be seen.

 

[xgillian89x]

Sorry I just read back my messages and I meant to put in my reply the first time that I use aqua safe

 

[Ninjouzata]

It is a dechlorinator. I was asking what kind you use because some can give false readings of ammonia. I don't think that one does but like Daize said test kits can be inaccurate.
 
What do you mean by the no nitrates? You seemed concerned about the nitrates being at 10-20 but that is a normal level. You want ammonia and nitrites to be at 0 though.
 
Which fish died?

 

[xgillian89x]

Yes the nitrates were between 10-20 before the water change but now there is 0 nitrates. I didn't do the water change because of the nitrates, they were due one anyway. Current parameters are 0 nitrites, 0 nitrates and 0-0.25 ammonia. It was a lemon tetra that died

 

[b3cca]

What is the PH ? I wouldn't imagine 0.25 ppm ammonia at a lowish Ph is toxic at all certainly not enough to instantly kill a tetra.
Could even be that the fish died of something totally unrelated and the dead fish carcass in the water then slightly raised the ammonia.
 
Either way, same action as with any above 0 ammonia readings, just do a few daily PWCs and keep monitoring the parameters

 

[TwoTankAmin]

I am not a big fan of Tetra's site. trying to get detailed information about any of their products is difficult. I cannot determine if Aqua Safe contains and ammonia detoxifier or not, It also contains ingredients i do not allow in my tanks in the form of anything claiming to enhance fish slime coats. I will never use such products.
 
Here is why the ammonia detox part is relevant. Chloramine used to disinfect tap water is a mix of chlorine and ammonia bound together. In the presence of dechlorinators the chloramine breaks down into its two components. The chlorine is neutralized but in the absence of an ammonia detoxifier, the ammonia is not. This can create a small amount of ammonia that could be tested soon after doing a water change. However, the bacteria should be able to deal with this pretty fast in a cycled tank so such an ammonia reading should not last.
 
the other side of the coin is that at .25 ppm on an API kit for ammonia to have killed your fish fast you would have to have a pH in the range of 8.4 or higher and a temp of 80F or above. The problem is this should affect more than one lone fish. I would go with the idea that other issues killed your fish, not ammonia.
 
A ,25 ppm ammonia reading cannot persist at that level in a cycled tank for very long, the bacteria will step up and handle that easily.

 

[xgillian89x]

Sorry I didn't notice I had any more replies. The ammonia went away after a couple of days I just did a water change. Everything is back to normal again, just trying to tackle the algae which is getting out of control thanks for your replies x