Suicidial Fish! :s

[Eddsch]

Hey all,

So I recently finished cycling my tank, did a 80-90% water change and went out and bought 6 Harlequin Tetras. My ammonia/nitrites were 0, my nitrates ~10-20, so all seemed well.

Once I brought the fish back home in their bag, I floated it in my tank water for around 15mins so they could adjust to the temperature, then every 5-10mins I added around 25% tank water into their bag, repeated a second time, then scooped em out with a net to put em in the tank and disposed of the pet store water.

At first they seemed fine, explored the tank together and all was well. After a while and they looked like they'd settled, I popped out. When I returned to feed them, 1 had already gone missing, but I thought perhaps he was just a little timid and was hiding within the tank. Next morning, only 3 are swimming around, and I find 2 on the floor by the tank! Presumably they'd jumped out.

I'm not sure what could be wrong - the temperature was around 25-26 deg. celsius, and everything else appeared to be fine. My only thought is that my pH seems to be around 7.5 (i'm based up in Leeds) - could this have been a cause of the stress which lead to their actions? I bought the fish on the Saturday, the 3 had disappeared by Sunday morning, but the other 3 seem fine as of today (Tue morning).

FYI: My tank is a AquaNano 40 (55l), new, fully cycled over around 8-12weeks.

Thanks for reading!

 

[ZoddyZod]

regardless of the water stats, some fish do jump. I'd invest in a lid of some sort.

Also, Harlequins are rasborra, not tetra.

 

[Alm0stAwesome]

Hi there, sorry to hear you've lost some fish. I've got espei rasbora and they have jumped out of buckets on me before so I agree, a lid is a must with these little guys.

 

[Eddsch]

regardless of the water stats, some fish do jump. I'd invest in a lid of some sort.

Also, Harlequins are rasborra, not tetra.

Ah okay, thanks, won't forget.

I do in fact have a lid which covers the tank, but there is a small gap on one of the corners to fit your finger in to lift the lid off (it's a glass lid), so it's very small, but judging by where I found them on the floor it was here where they escaped through.

So perhaps it was just excited fish getting a bit carried away?

 

[ZoddyZod]

could've been skittish due to their new surroundings. Tape up the hole for a while until they calm down

 

[Eddsch]

Okay thanks a lot.

I'd just like to check that my pH (around 7.5) is okay for the fish? Also looking to add some tetras in too (neons) and perhaps a different type of tetra some day.

I understand it's quite difficult to permanently change the pH of water, and that high pH's aren't great for breeding fish but I'm not concerned about that, I just want happy fish!

Ta

 

[Alm0stAwesome]

I personally think your pH is fine, most fish are quite adaptable

 

[coldcazzie]

I'm in Bradford and have a group of harlequins, they've always been fine (even in open topped tanks) for me - very reliable little fish. As ZZ said, it's very possible it's nervousness due to being moved (often fish are not in the store long before being moved again), and it only takes a small hole for them to jump out, although as I said, I've got 12 in an open topped tank, and before this tank they were in another open topped one for 8 months and no problems

 

[Eddsch]

So after further investigation, it seems the fish are swimming up against the current from the air pump (which pushes them toward the corner they escaped from), and swimming a little too hard/getting carried away and shooting up the side and out the corner! I've rotated the lid round so the corner they're doing this is has no gap at the top. Is this a normal thing for fish to do? Are they doing it for fun? Seems only the Harlequins are doing this, and not my new neon tetra.

Any thoughts?

Thanks!

 

[Salam]

My harlequins love swimming in the current. It's their fun time activity. Nothing to worry about.

 

[OldMan47]

I have kept harlequin rasboras, not tetras, in my local tap water. That means they saw water with a pH of 7.8, a very high mineral content of around 225 ppm of TDS and very hard water with both the GH and KH values around 12 degrees. I run a tank temperature of about 24C so even that parameter is about like yours. I seriously doubt that your water parameters are any problem at all. I can only speculate that some other factor, like a bare tank might present for example, must be the "cause" of your issue.