Hi,

just wondering if someone can help me get to the point of my bistlenoses dying.

I had 2 bristlenoses which died within 2 weeks of each other, They were fully grown but not old as I had raised them. Tank is 320 litres, PH is 7.2, Ammonia=0, Nitrite=0 and Nitrate=10. Tank is heavily planted and have lots of drift wood in it.

I do fortnightly water changes of 50%. Tank is shared with other community fish that all seem happy and breeding.

I vary the food daily and included flakes, shrimp pellets, blood worms, cooked peas, catfish pellets and algae wafers.

I've had the tank for about a year and whilst I've had trouble when I first got it, these guys survived it all and things have been settled for about 6 months now.

Why is it that only these guys are piking and everything else seems fine? Must be one thing these guys don't like. I have one more tiger plec left and would hate to see him go (especially as he was so expensive!) So if there is anything I can do to"save" this guy I'd love to know.

So my thoughts are that it could be the 1 tablespoon of aquarium salt I add with water changes. Now I know this has sparked many arguments on previous posts as to whether people agree with this or not, but I did lots of reading and seeked lots of advice and and was assured this small amount of salt would not cause problems. But I know catfish aren't that keen on salt. But they have been living in the aquarium with it since babies...

I've also recently started adding potassium and iron to the water ( as per instructions on Flourish bottle), but could that be upsetting the fish?

Any advice appreciated!

What sort of temperature is your tank getting up to during the day. I found that while my younger bn tolerated my tank heating up during the summer my adults did not.

How much evaporation goes on with your tank - as water evaporates the salt concentration rises. If you are concerned and have a lfs with marines or know a marine keeper near you ask them to test the salinity level in your water.

About 3 weeks ago I lowered my tank temp to sit around 25.5 degrees as it heated up too much during the day (got to 29 degrees once). It sits pretty stable at that temp now especially since we've not really had a hot summer.

I don't seem to have too much evaporation. Certainly nothing noticeable between water changes.

I have a similar problem only its with guppies

Just found what may be causing the problem. Was sitting looking at my tank and realised the filter flow wasn't as expected. Opened the filter up and a piece of Java moss had clogged up the intake, how long it has been like that I'm not sure. Filter was last cleaned about a month ago.

Any explanation as to why only the plecs died though? None of the other fish seems to be in distress.

And should I do an urgent water change or leave the filter to now do it's bit again?

Tested the water again tonight and Ammonia=0, Nitrite=0 and Nitrate=10.

Some fish are more sensitive to changes than others. Also, it you did not have as much flow going on at the lower levels, it would affect those fish more perhaps.