What's Up With My Rtbs? Help!

[paiger91]

Where do I start..?
Lets just say I'm a beginner with tropical fish after my boyfriend decided he wanted them. However, it seems to be me that is looking after them!
About a week ago we got a red tail black shark who is normally very lively. We're assuming he's quite young as he is still very small (about 3.5cm?)
But yesterday I noticed he has hidden himself away in the corner by the filter and is being very still (still moving all fins, but not really swimming anywhere) and is vertical (facing the bottom of the tank)! At a closer look his right pectoral fin doesn't look too good. It looks thinner (in width) to his left and seems to have a very slight jagged edge.
I feed them every other day (a varied diet of flakes and bloodworm and I occasionally drop in a crushed up frozen pea.) When I fed them today he swam out to have a look but didn't eat anything and went straight back to his hiding place, back to his vertical position.
I don't know much about diseases, I just know of white spot and fin rot but I do know that there are others. I can be a bit of a hypochondriac at times - which I'm aware of - but this makes me wonder if I'm over reacting or if I've told myself not to panic over something that could be more serious than I think.

What can I do to save him, or is it too late?
Please help!

 

[fluttermoth]

The first thing to do if your worried about a fish is to do a large (75 or 80%; leave just enough water for the fish to swim upright) water change, making sure the new water is warmed and dechlorinated and see if he looks any better.

How big is your tank, how long has it been set up and was it cycled at all? Are there any other fish in there, and if so, what kinds and how many?

 

[paiger91]

The first thing to do if your worried about a fish is to do a large (75 or 80%; leave just enough water for the fish to swim upright) water change, making sure the new water is warmed and dechlorinated and see if he looks any better.

How big is your tank, how long has it been set up and was it cycled at all? Are there any other fish in there, and if so, what kinds and how many?

It's a 20L and we have 5 neon tetras, one black molly and the shark. and I don't know if it's relevant but we did have a Congo frog until he died about 5 days ago. (we think he jumped on top of the filter, got stuck and dried out).
and the tank was set up 4 weeks ago, and we left the water to settle for 2 weeks before adding any fish) and yes the tank was cycled.

 

[the_lock_man]

The first thing to do if your worried about a fish is to do a large (75 or 80%; leave just enough water for the fish to swim upright) water change, making sure the new water is warmed and dechlorinated and see if he looks any better.

How big is your tank, how long has it been set up and was it cycled at all? Are there any other fish in there, and if so, what kinds and how many?

It's a 20L and we have 5 neon tetras, one black molly and the shark. and I don't know if it's relevant but we did have a Congo frog until he died about 5 days ago. (we think he jumped on top of the filter, got stuck and dried out).
and the tank was set up 4 weeks ago, and we left the water to settle for 2 weeks before adding any fish) and yes the tank was cycled.

Sorry to say this, but there's a few issues.

THe main thing is that I very much doubt your tank is cycled. By this I mean that your filter hasn't yet grown 2 colonies of bacteria, which can process the ammonia produced by your fish, first into nitrite, and then into nitrate. Unfortunately, although many fish shops recommend people do this, it actually does nothing to grow those bacteria, as they need a source of ammonia (eg fish) to survive.

I think your fish is/are suffering from ammonia poisoning, and following Fluittermoth's advice above is the first thing you need to do.

There is a really good article about your situation called "Fish-in Cycling", it's in the Beginners Resource Centre, the link to which is at the top of the "Your New Freshwater Tank" section of the forum.

Unfortunately, I can't leave it there. A 20l tank is way too small for a RTBS, a molly and 5 neons. I would strongly recommend taking all the fish back to the shop where you got them.

If you do that, you could easily switch to a fishless cycle (details of which are in the same section of the forum) and not risk any ill health of the fish. You could have a single male Siamese Fighting Fish (aka Betta) in that tank, but not really much more than that.

 

[DrRob]

OK, Fluttermoth's advice is good. Do the water change.

You have there quite a small tank (as tanks go) with a heavy load of fish for it's size starting over quite a short time.

In that circumstance, whatever you did to cycle your tank over the last 4 weeks won't be coping, and you'll be getting a build up of ammonia and possibly nitrite. If you freshen up the water you should see some improvement, otherwise you're going to lose the others too. Given that we suspect you're dealing with a toxin that you're trying to dilute you want to change as much of the water as is feasibly possibly. When I've had to do it I took the tank down to just enough water from them to swim in and then filled it back with fresh (with dechlorinator). The fin issues will, most likely, be due to poor immunity due to the toxins. Good news in that it's probably not a nasty infection as such, but dangerous for your fish.

There's a fair bit more advice people can give you. The more details we can get on what kit you have and what filters and things you're using the better that advice will be. For now I'll leave you with the water change and the consideration that that size tank is going to be hard work to maintain with a rtbs in the short term and impossible as it grows, so there's going to have to be some thought on what you're going to do with your stocking.

 

[paiger91]

we had previously set up a tank which had 3 mollies and 4 neon tetra. that was up and running for about 3 weeks but the shop hadn't told us to cycle it so when they started dying a friend of a friend took our remaining fish (1 tetra and 1 molly is all that survived) and we started again. I was then told that because the tank had been previously set up there should already be bacteria growing in the filter ready for cycling?
Also we are about to move the fish to a bigger tank which we are going to set up this weekend. this is a 98L tank. that's why my partner bought the shark: because we were told "1cm of fish per Litre of water" it worked out as 10cm of tetra, 2.5cm for the molly and 3.5cm shark, he thought it would be ok for 2 weeks until we transfer them to the bigger tank.
All our other fish seem fine, it's just the shark?

Do you think I should take the water to be tested? will that help with a diagnoses?
And how should I set up and cycle the new tank to make sure it's done properly, as I seem to have been misinformed twice now. Thank you all for your help...

 

[the_lock_man]

The 1 cm/l thing is adult sized fish, not what's currently there. The RBTS will grow to around 15cm, the neons about 4½ each, and the molly about 7cm.

There may well have been bacteria growing, but if there was any period of time where there were no fish, then the bacteria would have started to die back, and if the filter media dried out completely, then all the bacteria would have died.

In your situation, please read this. To do this properly, you need your own liquid-based test kit, they're about £30 from Pets @ Home, and less than that on Ebay. If that's still a problem money-wise, just get ammonia and nitrite for now, and save up for nitrate and pH.