[jamal6008]

Hi

I've had a 230L aquarium for about 8 months now. The aquarium has reasonable amount of live plants.Over time the fish had a lot of fry so the biological load of my tank has increased with time but it seems like things have been okay. After a very long time I just tested the water and got the results:

ammonia 0.25 ppm
nitrite 0 ppm
nitrate 0 ppm
pH 7-7.8
Water temperature: 25.5C

I've previously not had time to do weekly water changes and have stuck to big monthly water change. I was wondering that now that I have more time should I do weekly water changes or just leave things as they are if water conditions are fine? I want my tank to be as self-sustainable as possible.

 

[corina savin]

How long after a water change did you measure this ammonia?

 

[jamal6008]

It's been 10 days. I also use liquid plant supplement

 

[corina savin]

Ammonia right after a water change might signal cloramines or even...ammonia in your tap water.
Some liquid fertilizers also have ammonia. I have a bottle of "Nitrogen" plant supplement by Seachem. It says on the label that it has half and half Potassium nitrate and Ammonia (in a form that is not dangerous to the fish)

 

[jamal6008]

Yup I thought that might be the case. But I am sure 0.25 ppm is not a big deal. It's only just after 0 level. Good thing is that there are no nitrites and nitrates right? What about water change duration?

 

[corina savin]

I'll rather have nitrates than ammonia or nitrites.
Not big deal unless it persists. A properly cycled tank should clear it fast. I would keep an eye on it. There is no safe level for ammonia.
What tests are you using? The pH of 7-7.8 is quite a range...

 

[jamal6008]

Yeh I'll do the test again in few days. I wasn't sure about the pH because I am using API test kit and the colour scheme is a bit strange which makes it very hard to tell the pH. So I decided to put an estimated range instead...

 

[jamal6008]

Right I found a dead fish (molly) this morning. It has been a very long time since a fish died in my tank. It wasn't an adult fish but I would say it was just over half the size of an adult fish.

I have not tested the water again yet but I have a suspicion that it wasn't due to water condition. I am wondering could lack of oxgen cause a fish to die? I have my tank filled with fish to the max if not overcrowded and a lot of live plants which means at night time there is a lot of oxygen being consumed.

Although I have an external filter that does break the water surface really well with its flow. I also leave the lid of the hood open all the time.

 

[corina savin]

Lack of oxygen will kill all your fish, not just one. Oxygen levels are lower but not zero before light are on. In heavily planted tanks, you can see fish at the surface, closer to air because of lower oxygen levels. Plants experts (with CO2, high light and tons of fertilizers) use airstone to bubble air at night. Again, to provide oxygen to plants (not fish). The loss of CO2 in this case doesn't matter, more will be injected in the morning.

 

[jamal6008]

So do you think its worth buying an air bubble? I have also noticed strange behavior in some fishes. Its not in all of them but in some of them, they just seem to stay still at random places of the tank and not move at all. Sometimes it would be in corners or sometimes even in the middle of the tank.

 

[corina savin]

Airstone in planted tank is a long controversy. I, for one, don't have any. It will drive more precious CO2 out than will bring oxygen in. If you ask me, no!
About fish that don't move much...I don't know. And when I don't know what's wrong with my fish, I always do a large water change. You can never be wrong by doing that (assuming it's not the first water change in months....)

 

[Absntmind]

"nitrate 0 ppm"

Nitrates shouldn't be 0 in a cycled tank.

 

[jaysee]

"nitrate 0 ppm"

Nitrates shouldn't be 0 in a cycled tank.

Depends entirely on the bioload of the tank and the degree to which the tank is planted. It's very easy for a cycled betta tank to have 0 nitrates. Too, some people actually run Into a problem with Cyanobacteria because their nitrates are so low.

 

[jamal6008]

My university work load is driving me crazy and this is really bad time for fish tank to start acting up. Another fish was found dead I am going to do a full water test later today after my exam, both before and after I do a water change and come back with results.

 

[jamal6008]

Okay I just tested the aquarium. Results are very similar to last time.

Ammonia 0.25 ppm
Nitrite 0 ppm
Nitrate 0-5 ppm

I don't understand if water conditions are fine than why did 2 fishes die? Why do other fishes still seem to be hiding/staying still most of the time?

I am going to do a water change.

 

[corina savin]

That ammonia should not be there a week later. Either the plants or biofilter should have cleared it.
I would test ammonia against tap water or another tank water (if you have any). That's what I do with nitrates. I test at least 3 tanks at once and I compare the color side by side. I probably have a crappy color chart, I don't see the difference (looks a lot darker if touch the vial against the plastic card).
Now: having zero across ammonia, nitrite, nitrate does not mean perfect water condition. There are a lot more in the water that can go wrong and we don't have tests for everything. People realized they have soap, chlorine, nicotine, air fresheners, hand lotion, nail polish, leaching decorations unsafe for tank, electric shorts, etc. I know its not your case. What I mean is that perfect nitrogen cycle is not all.
Again. I suggest a water change (don't forget the de-chlorinator). Let me know

 

[jaysee]

Agreed, there's more to "clean" water than just ammonia, nitrite and nitrate - lots of things can harm your fish for which you simply can't test, which is why ANY time the fish start acting weird a water change should be the first thing you do. Even before starting a thread here

And along the same lines - there are tons of reasons why fish die, many of which can have nothing to do with the water.

 

[jamal6008]

Thanks for the reply guys. With regards to ammonia levels, I put the plant supplements in every day so if supplements is the reason why its high it will not go away whether its a week or 3 weeks.

 

[jamal6008]

Update:

I just did 40% water change and cleaned the glass (got rid of algae etc). I didn't forget the de-chlroinator

I found two more dead fish while I was cleaning the tank. They weren't visible before but somehow came floating to the surface after I took water out. One of the fish was full adult size neon tetra and second seemed like a few months old molly.

I am going to test the water after few hours just giving time to tank to settle down. I have not put any plant supplements today. I am planning on doing another 40% water change in a weeks time.

Anything else I can do or any comments on this?

 

[jamal6008]

Test results after water change:

pH: 7.5
Temperature: 26C
Ammonia: Somewhere between 0-0.25 ppm
Nitrite: 0 ppm
Nitrate: 0 ppm