Am I overstocked?

[ButWhyIsTheGinGone]

Hello all - relatively new to MN and pleased to have found this little section! :) I was wondering if any more experienced fish keepers could advise me on my current setup - I have a 300 litre cold water tank (4 foot in length) which I got as a second hand bargain from ebay.

In it I currently have: 2 Black moors, 3 White Cloud Minnows, 2 Albino Corys, 4 Zebra Danios, 3 Leopard Danios, 4 platys and 2 beautiful Dojo Loaches.
The tank looks (IMO) quite sparsely populated but the fish seem to be thriving. I did have 2 American Flagfish but after just one night of being in the tank they had shredded the hell out of my my poor black moors' tails!! So I now keep them seperately in a small 23l tank. I've had my big tanks set up for about 3 months and have had no deaths (touch wood).

Just hoping for other people's opinions really! TIA

Hmm, yes there are a couple of problems with your stocking levels. Grab a cuppa (or some gin if it's not all gone ).....

First of all- minnows and corys are shoaling fish so should be in groups of 6+. Less than that and they can start getting nervous and twitchy and their immune system suffers.

Platys are tropical fish and need a heated tank. If the tank is not heated then their immune system can't fight effectively and they are vulnerable to infections (especially fungal ones). Corys also need warmer water than goldfish, minnows and danios (depending on the exact species)

Corys, minnows and danios are all fairly small fish. Golden rule of stocking- anything that's small enough to get eaten will get eaten. I just heard a rather nasty story about a goldfish trying to eat a cory and getting it caught in its mouth- corys have spikes in their pectoral fins. Minnows are snack sized once goldfish are fully grown as well.

Dojo loaches are lovely fish! They can be safely kept with goldfish but they like to bury themselves so a sand substrate instead of gravel is best.

American flagfish need a bigger tank than 23 litres, I would suggest around 70 for a pair so that the female can get away from the male if she needs to.

Er... I hope that's not too much bad news! On the plus side, a 4 foot tank is a brilliant size for your moors and they should live a long and happy life in there.

Oh, you might like to read this.

Thanks for the quick response! Will try to respond to all points - so much advice! :-)

1. The minnows tend to shoal with the danios in one big group, but I would be happy to add more.
2. Corys - Pets at Home said 2 would be fine, but everything I've read since then contradicts this, Grrr!
3. Horrid story about the goldfish and the cory! Luckily I have a fish tank at work so can be a bit flexible with where I keep the fish. As an aside, I hope I'm not gonig to sound too dim here,) will the moors eat the fish having lived in the same tank as them for such a long time? Hmm, that does sound dim, I'm guessing!
4. The Plays were bought from PAH who classed them as "temperate" - they said they would be ok in a cold water, but again, my reading has indicated otherwise. I do have a 100 litre tropical as well with very little in it. Is it possible to move them over, or would the shock kill them?
5. I don't know what to do about the flagfish - I know they need re-housing, but it wouldn't be fair to give them away after watching them rip my fish to shreds...
6. Thanks again for all the advice! I do love my tanks - I thought the 300 litre one would be impossible to care for, but the water stays ever so clear!

No worries, I will respond equally quickly before I bugger off to do some gardening

1. Yes, a bigger group of minnows would be happier but they are not really goldfish-safe due to the size difference. I don't know how big your moors are now but if they are tiny then the minnows might be safe for the minute but long term they will need a different tank.

2. Oh, you've been Pets at Home-d. :( They can be pretty shocking with their advice. I've tried keeping corys and goldfish myself and it just doesn't work for so many reasons. My corys got bullied something chronic at feeding time- again, a size difference issue. Luckily for everyone involved I moved them over before anything worse happened.

3. No, fish are not sentimental about eating their tankmates. Too bad, eh?

4. Sodding Pets at Home Platys are not temperate (minnows and danios are though) Platys are from Mexico, Honduras, Belize, around that part of the world- it's pretty hot there! They need higher temperatures than most aquarium fish. You should be able to move them over depending on what you've got in your other tank. If you acclimatise them very slowly then they should be fine.

5. Flagfish are better off in a species only tank really. Is there a local aquatic club that might be able to help you rehome them?

6. Yep, those bigger tanks are defo easier to keep clean! That's why I hate those tiny little tanks that are aimed at beginners, those are the ones that are impossible to care for.