I have a 125 l tank, there's only 12 small fish in there. One of my guppies looked like his Finns were being nipped but then developed a fungi so I put some anti fungi and finrot treatment in but unfortunately he died the next day. The day after that my male dwarf gourami was dead but with no signs that anything was wrong. I then noticed today an odd chemical like smell and the fish all hanging at the top of the tank breathing more than normal.
The last time I used a medication I then had an ammonia spike and lost lots of fish so I thought that's what this might be but I have tested the water and the ammonia levels are 0.25 which is the lowest I can ever get my tank, its never been 0 and tap water with tapsafe in it also reads 0.25. N03 levels are 40 ppm and n02 levels are 0. I have done a 50% water change anyway.
If there isn't an ammonia spike, any ideas what it might be?
Hi thanks for replying! Tanks been set up for a couple of years, the last new fish I added was a couple of months ago, the only thing I've done recently is add 3 live plants as I haven't had any since the last ammonia spike.
The temperature is 26 degrees, n02 and n03 was on api test strip, ph is 6.5. Ammonia is the dropper type also api. There already a 15 cm airbrick which I've turned up. It's an external filter but the outflow pipe from this doesn't agitate the water much as its sits lower than the water level, hence why I always have the airbrick.
I just asked my husband and he said the chemical smell was a bit like bleach/ammonia. Think that's everything!
I had to use Interpet ammonia remover to reduce the levels last time but don't want to just put that in if the levels are low!
How often do you do a partial water change and how much each time? Do you use a dechlorinator? Do you regularly clean the gravel and rinse out the filter media? How long have you had the ammonia test? Is it still in date? What is the pH of your tap water? Is your water hard or soft?
I do about 20% every couple of weeks with a gravel Hoover. I don't know the tap water ph but I use tetra tapsafe. The ammonia test doesn't have a date but I've probably had it about a year.
When you ask about rinsing the filter media I did notice when I took the carbon out to put the finrot treatment in, when I reconnected it there was a good amount of dirty water that came out of the filter and through the outlet pipe back into the tank. The water then took about half an hour to clear. Could that have caused the problem? Do you think if I rinsed all the filter media out in some tank water that would help?
I would up the water changes to 25% a week, which is pretty much the starting point. Given that your tests apart from the ammonia test are test strips I suspect the nitrate level is a lot higher than indicated. Can you do a test for pH on your tap water?
I think probably what you have is what is known as "old tank syndrome" due to not changing enough water. It would be easier to tell with liquid test results so if you can get a master test kit it would be a good idea.
If you haven't been cleaning the filter media then that may have reduced the efficiency of the filter and reduced the oxygen level in the water too. The dirt recently released may have caused an ammonia spike and subsequent nitrite spike as well, but again as the nitrite test is a test strip we can't be sure.
What I would suggest is an immediate 50% water change with dechlorinated water at the same temperature as the tank. Hoover one part of the gravel (about 1/4) really well and wash out about 1/3 of the filter media in used tank water. Repeat that every other day for the next week until the whole of the gravel has been thoroughly cleaned. Also clean the filter housing and the impellor.
That ought to be enough to bring things up to scratch, but if you can get a master test kit in the meantime and do a full set of tests at the end of the week we can be sure. Assuming all is as it should be by then, start changing 25% of the water every week, hoovering half the gravel thoroughly on alternate weeks. Clean half the filter media in used tank water at each water change by just giving it a very quick rinse to get any loose muck off and check the impellor regularly.
Okay I'll give that a go, I already did a 50% water change with the gravel Hoover this morning, did I need to do that again today? Also if I rinse all the filter media at once in tank water will that harm the beneficial bacteria?
As you've done 50% already today there's no need to do it again.
Don't rinse all of the media at one go, do 1/3 at the next water change, another 1/3 the next time and then the final third. The bacteria actually release a chemical "glue" that holds them fairly firmly to the media so as long as you aren't too vigorous they should be fine. Don't try to get the sponges completely clean, just get the loose "slime" off and give them a squeeze in the water. The aim is really to make sure the media isn't clogged up so as long as that's achieved there's no need to go any further.
dbawldy wrote: just scanning through this post a little addition on what fish lady said... ensure you are replacing filter media on a regular basis and also watch out for any reduction in output from the filter
(i had a very similar problem recently although there was no fish illness as such)
I'm afraid I have to completely disagree on this one. If flow reduces, the answer is to clean the media. Regular replacement of media is not only unnecessary, but potentially catastrophic for your filtration and fishes' health. If filter media is thrown away all the beneficial bacteria are thrown away with it.
The only media that need regular replacement are carbon (which becomes exhausted) and filter wool which becomes clogged and ineffective very rapidly. These don't harbour much bacteria so are safe to be replaced, although both are optional and not essential.