Bristle Nose Deaths

[daveysfish]

Hello , just wondering if anyone has any ideas to why all 3 of my bn's died. I had one in each of my tanks, one in 54ltrs was about 3 inch, one in 37.5 ltrs at about 2-3inch and one in my 40ltrs tank at about 4-5inch. they were brilliant little workers, every tank was spotless of algae.
I always test water after a death,the last one to pass away was 2 days back and i found that ammonia and nitrite were zero but nitrate was present at around 5-10mg/l.
What puzzled me was i had serious nitrate problems a few months back when they were up to 75+ mg/l in my 37.5 ltrs (blood red on the interpet tablet test kit) and around 50-60 mg/l in the 54 ltrs and they all survived that emergencey. Are bn's extra sensitive to even low(ish) nitrates? or is there a possiblity i could have spread some sort of disease between tanks with nets and hands at feeding time beacuse the water in the 40ltrs was perfect.
If any one could help I would be greatful, to late for my bristles but would like to have an idea what could of happened so it does'nt happen again. Look forward to hearing any replys, thanks Davey

 

[LisaLQ]

Did they show any signs of illness? I wouldn't 100% trust parameter tests unless they were the ones you do in a test tube - dipsticks and tablet ones are generally rather inaccurate, so there's a chance the results were wrong. Also your tanks are too small for bristlenoses, the absolute minimum would be a 15g for one, but personally I'd think bigger as they can get to 6" and the amount of waste any plec makes means that being in anything smaller would mean the water would become incredibly toxic very quickly.

BNs are pretty hardy plecs, one of mine survived a very high nitrate spike at one point in my hubby's tank, but like any fish - a regular high nitrate rate can cause death. I wouldn't be overly concerned about a level of 50, it should really be under 40, but I dont think it would kill to be at that level for a short while, as long as it wasnt regular or long term.

But I'd think in tanks your size, with a bristlenose - and I'm assuming other fish (can you tell us what else were in the tanks?) - the params would be worse than your tests say. How often do you do water changes and gravel vacs? Have you added any new fish recently?

I think sometimes there's no easy way to work out what a fish died from - but I would say tank size and possible high nitrates would certainly be a factor in your case. If you're thinking of getting another bristlenose, I'd think of a tank upgrade first

Sorry I couldn't be of more help!

 

[daveysfish]

Liquid test kits are accurate but go out of date quite quickly and can be giving poor results in 5-6 months after opening ( I used to throw away lots of these liquid tests being used in the health and science industrys in one of my old jobs), dipsticks are crap so i settle with the tablet test where i know they won't be accurate to the decimal point but do the job i need.
filtration wise all my tanks are double filtered the 54 ltrs has a sera fil 380 (rated upto to 60ltrs /15.9 gl) and a Shark ADV (rated to 130ltrs /34 gls). The 37.5 ltrs tank has 2 Fluval plus 1 (rated upto 45 ltrs each) and the 40 ltrs tank has its own built in filter and another fluval +1 . After the nitrate spikes i waterchanged them out like crazy and have kept a good regime of waterchanges at aprox 30% a week since then. Stocking low-med level but not crazy, mainly corys. 54ltrs has 10 corys, 1 banjo cat, 1 king tiger plec(about 1.5 inch approx). The 40 ltrs has 3 corys and 1 adult angel. 37.5 ltrs has 3 corys, 1 zebra danio and 2 mystery tetras.
I keep thinking back a couple of years to when i saw a batch of 25-30 gibby plecs all die within a space of 48 hours without any clue to what happened, still a mystery to this day. but makes me think that it could disease related.
Il miss me little bn's though, great algae eaters. davey

 

[LisaLQ]

I hate to say this but the stocking isn't low/medium, you're very over stocked. In a 54l tank, 3 cories or 5 dwarf cories would be ok, with 5 small shoaling fish (tetras, raspboras) - but that would be it - no plec, no matter what the filtration was like. Angels need a minimum of 30g from what I hear (I keep 6 in my 135g), the tank needs to be at least 18" deep for them too. Banjos can get to 6" so have no place in a 54l tank, same as the BNs. IMO you really would need double that at least for the fish in that tank, preferably bigger. I have no idea how an adult angel would fit in a 40l tank

I dont think there's much of a mystery, in tanks that small, the fish were probably highly stressed, and long term stress = death. Just out of interest, where did you put the gibbies? Please dont say in one of those tanks...

 

[daveysfish]

yeah put them all in a 2 gal tank in me garden!!, they were a friend of my dads who used to do importing. Used to have strange mass deaths for no apperant reason, he was always on top of his water quality. filters were massive with u.v sterilisers, trickle towers, sand filters ect.
You made me Think about the stocking so got me calculator and tape measure out. Using the 75sq/cm per cm rule i worked out the 54 ltrs has a surface area of 1950sq/cm and the stock at its current size requires 3375 sq/cm (wow!!). The 40 odd ltrs had a surface area of 1125sq/cm and current stock size would require 1325 sq/cm. the only one that come out alright was the 37.5ltrs with a surface area of 1250sq/cm and a current stock level requires 900sq/cm . All my calclations are on current stock size and not full potential size and with a D in GCSE maths.
Ammonia and nitrite are always zero in all the tanks, just nitrates come and go but usally go down after a good hoover. Just need to look forward to when i move out to a new place then im ready for my 6 footer. Thanks for the advice and im now going to shout at my dads mate for rubbish advice and down to the LFS for a thinning out session

 

[daveysfish]

Iv done my sums wrong, second go then . Going by a call to my LFS and a few books (Aquarium fish ,Dick mills and Aquarium owners manual , Gina Sandford) there rule is you need 75 sq/cm surface area per 2.5cm of fish , not 1cm of fish i worked out before.so the new sums are
54 ltr surface area 1830sq/cm
current 45 cm of fish require 1350sq/cm
max potential growth 92 cm would require 2760sq/cm (should be on a 6' tank by then)

43.5 ltr surface area 1125sq/cm
current 19 cm of fish would require 570sq/cm
max potential growth 30.5cm would require 915sq/cm

37.5ltr surface area 1250sq/cm
current 16cm of fish would require 480sq/cm
max pontential growth 33 cm would require 990sq/cm

Max pontentials used were-
Cory 6cm
angel 12.5cm
banjo 13cm
tetra's 5cm
tigerplec 12cm

LFS put my mind at rest anyway, but they know im due for an upgrade soon so want to keep me going back to them