BN idling all the time, what's going on?

[Featherless]

Hello, long time lurker here

For the last year or so I've been keeping a happy bristlenose in my goldfish tank, the typical BN always busy keeping the tank spotless, and especially fond of diatoms. She grew from little over 1" to about 3-3.5" in ~8 months. This summer, about July, things started to change.

She has progressively reduced the amount of cleaning, to the point she now spends most of her time idling behind the intake strainer pipe. This fish has always been very active and could be often seen working even during the day: not anymore. Also she stopped hiding in her coconut hut.

Following a BBA outburst, I have had dying or dead BBA available for quite some time, which the BN would have made short work of in the past; this time only the snails and goldfish are eating them. More recently, diatom patches appeared, the bristlenose has completely lost interest in those too. The woods are not as bad-looking as they could, so I guess she's still taking care of them, though not as hard as she used to.

I don't think she's overfed, it's been a long time since I gave her something. Usually she lived off algae and greens/gel food stolen from the goldies (something she's rarely doing anymore).

I'm really perplexed... I don't know what could be causing all this inactivity. Can you help me?

1. Water parameters
a) Temerature range: 22 - 28 (summer) dC / 72 - 82 dF
b) pH, natural around 7.6. After CO2 enrichment, around 7.1.
c) GH about 15-16
d) KH 11
e) Ammonia, Nitrate, Nitrite, levels. Total Ammonia normally 0 (0.4 when treating with H2O2), 0 NO2 (not tested for this in a long time), NO3 20-40
f) Water change frequency, 50%+ weekly

2. Tank set up
a) Size. 29g
b) Substrate. river gravel
c) Filtration. canister, nominal 395 gph, vertical spraybar. Loaded with sponge and ceramic biomedia.
d) Furnishings. cononut, a couple woods, rounded rocks.
e) Other tank mates. 2 common goldfish, 2 apple snails
f) How long has it been set-up? 1y 2m
g) When was the last new fish added? last new fish was the BN, snails added july and september this year.
h) Foods used and frequency? goldfish are fed shrimps, zucchini, gel food (greens), goldfish pellets, bottom feeder food. Haven't fed the BN

3. Symptoms / Problem description
Spends most of the time idling behind the intake strainer pipe. Totally uninterested in diatoms and other algae happily growing around the tank, on the glass and rocks.

4. Action taken (if any)
Nothing.

5. Medications used (if any)
Nothing.

[naturalart]

I'll take a shot at it. Could it be a behavioral thing: are the goldfish pecking at its "bristles". this could cause the BN to go into hiding and goldfish are know to worry other fish. They can worry snails to death. My male BN can sit for long periods and he's in great shape. Other possibilities could be dissolved oxygen, your pump could be losing some "umph", or maybe add an airstone. Check out her breathing pattern, it shouldn't be rapid. Breeding behavior possibly: going through hormonal changes? Dietary: maybe you could try a 3 inch chunk of zucchini inoculated with algea wafers and weighted down, that might pep her up? Are you vacuuming the gravel? Have you looked closely at the fish. Bloated belly: eating wrong food, sunken eyes and/or hollow belly: starvation, ripped or worn fins stress, possibly from other fish. A fish could be eating but not getting the right amount of vitamins and mineral. Do you know what species of BN you have? There are quite a few. And you could watch behavior after the lights go out, strange things happen in the dark. Is there an outside influence who could be shocking the fish by banging on the glass? Like a cat or a kid?

[andywoolloo]

first thing that pops out is your keeping a tropical fish (BN) with cold water fish, (Goldfish)

second thing is your temp range stated, 72 -82 those swings cannot be good for either fish.

72 is more goldie and 82 more BN.

Also the goldies are voracious eaters, maybe the BN cannot compete? I feed my BN's every day. They always have fruit and veg to graze on along with romaine lettuce or spinach leaves every day. And once a week they get defrosted frozen, spirulina shrimp, bloodworms etc. they also get sinking algae wafers and sinking tropical wafers and sinking shrimp pellets.

He doesn't sound too happy if he has deserted his coconut hut for to hide behind the intake strainer, unless he is just eating algae off the glass there?

[Featherless]

First of all, thank you for taking the time to reply. A lot of points have been raised and I'll try to quickly examine them all, so we can exclude what is impossible and focus on what's more likely.

The goldfish aren't hassling the BN (which is a common Sp. 3/cirrhosus), I assumed she's a female since in the last year her bristles haven't grown more than 1 mm long. Both the fish and snails are known to generally go peacefully along and even share food sometimes, the occasional dispute is soon dismissed. The tank is densely planted, I used to test for oxygen over the summer and it always looked fine, I've neither seen snails leaving the water or using their syphon too many times, nor the fish gasping at the surface.

I periodically check the tank at night but there's not much going on. Gravel is vacuumed at least every week at each major water change. There are no kids or pets messing with the fish.

Regarding temperature, like I said 82F a peak during summer (no chiller or A/C so the tank must face whatever weather I have to endure), 72 is the minimum temperature that I try to keep during the cooler months. AFAIK the temperature is compatible with all the of tank inhabitants' requirements, I think I did my homework

Something I forgot to mention: this summer I also changed the 'scape' of the tank. But it's been stable for the last 2-3 months, she should already be used to it.

The fish to me looks OK: the fins and eyes look pretty good, and as far as I can tell she's got bigger and rounder about midyear, but nothing that hits my eye as strange. Is it possible she is feeling 'lonely' or stressed because she can't breed?

These days it's very difficult to take a pic of her, I'm attaching the most recent shots I've got, from the summer. Keep in mind there's some distortion because of the glass. If I manage to take another pic, I'll post that too.

[Birger]

She seems to look healthy enough to me...I think what you are noticing is behavioral changes as she is getting older, they will not be as active as when young and become more reclusive.
I think you should feed food specifically for her... veggies as suggested above giving a while to let her figure out it is food you are offering, so you may have to change it out even it seems she is not eating but soon you will notice she has been finding it.(the snails may find it as well)

And as far as her being lonely...it is always interesting to add a male...adds another element to the tank

[MatsP]

Temperature swings is not good for any fish, but 72'F is OK temperature for bristlenoses, and should be acceptable for goldfish too. As Birger says, as they grow older/larger, they become less active (this applies to almost all creatures, fish or otherwise - just look at the difference between a 3-month old kitten and a 3 year old cat).

--
Mats

[Featherless]

I understand fish change with age too, but this one looks a bit too big and sudden. It's almost like she's turned into a hermit living off bread crusts when around her there are tables filled with food... yesterday and today there were zucchini lying around that the goldies didn't eat and they mostly went to snails. Not to mention the amount of diatoms and hair algae which she usually ate in no time.

As for finding a mate, all the BNs on sale in the LFSs are youngsters about 1-1.5" long, I'd be hard pressed to tell a male from a female. Besides I have doubts my tank, which has a footprint of about 40"x12" and a net capacity of 24g, can support another fish without water quality taking a hit.

I'm also wondering why she doesn't like the hut anymore. Maybe it's not comfy enough anymore? I could replace it with one of those gravel covered tubes and see if she likes that one better.