Looking For New Additions

There are two reasons for not keeping large and small fish together - the large fish might eat the small fish or their physical size might intimidate the small fish. In the case of the fish you name I suspect the latter.

Rainbowfish, for example, won't be able to eat cardinals let alone harlies because they have very narrow throats for the size of the fish. Provided your hardness is OK for the species of rainbow you like, they should be fine.

Silver dollars are quite big fish. Seriously Fish recommends a tank at least 6 foot/180cm long. Unless your tank is that size, I would give silver dollars a miss.

Giant danios would also fall in the 'intimidation' category as danios of all sorts are fast swimmers. Like the smaller zebra danio, these fish like the water a bit cooler than cardinals at 18 to 25 deg C so if you go with these, turn the heater down a bit.

Pearl gouramis. The CC is the thing that put me off these fish as I have smaller fish than you. They are calm fish, unlike rainbows and giant danios, so they shouldn't stress your current fish with their activity. I suppose they might try to eat the cardinals - I think harlies are safe because of their body shape and gouramis wouldn't find kuhlis unless yours are out and about all the time.
Seriously Fish gives the max size for pearls as 12cm. There is the slightly smaller (10cm) thick lipped gourami as an alternative, if you can find them.


Given the fish you mention, I assume you are looking at midwater fish rather than bottom fish? Some of the small cichlids would go nicely with the fish you have, fish such as apistogrammas, bolivian rams, Laetacaras, Nannacaras etc. Or kribs if you want African fish. But they are mainly bottom dwellers.

I have found with dwarf cichlids breeding that they don't bother mid water fish. Maybe a bit of chasing but no damage done. I'd better qualify that: when I had bolivian rams and cockatoo cichlids breed in my tanks, they didn't harm their tank mates, just chased them away from the immediate vicinity of the eggs.
I have no experience of kribs or Laetacaras, and my Nannocaras didn't breed before succumbing to camallanus worms, so they might be more aggressive.



Richard, how would you feel about pearl gouramis with Helen's fish?
Or with mine, I still have ember tetras, green neon tetras and Microdevario kubotai? I'm thinking of getting more embers when I can go shopping, but the rest of the new fish are yet to be decided.

Ooh, lots of food for thought, thank you. Basically my tank has been a bit neglected recently, but surprisingly my fish have survived, except for my corries. I know I need to re establish a much better maintenance regime before I buy any more fish, but thought doing a bit of research and having something to aim for would help motivate me to make the time. My small shoals of harlies and cardinals look lovely in the tank, and I'm thinking about adding to their numbers, but actually struggle to count and keep track of them if there are more than about a dozen.

I'm trying to find a fish or two that are a different size to the existing shoals to add interest. I have considered angels in the past, and still would, but am worried that they could be hard work if I happen not to get ones with friendly dispositions.

When I first started my tank, I had dwarf gouramis, zebra danios and a bristlenose plec. Sadly they didn't do very well, but I'm not sure if that was because of my water conditions or because I was struggling to establish my tank. If it's the latter I'd be tempted to go for them again (not dwarf gouramis, but another sort), but would want to be sure as I wouldn't to risk killing them.

Now my tank is doing better than really it should!

Am I aiming too big, looking at fish that have a max size of 12cm?

Thanks for your comments.

I've just remembered why your tank has been neglected. She's 2 any day now, isn't she?

I knew there was a thread somewhere 

You mentioned angels in here. Is this the thread you were thinking about?

What are usually called Emerald cories are not true cories but Brochis splendens which grow much bigger, up to 8 cms, and need a bigger tank. There are lots of smaller pretty cories all of which have very similar requirements, it's matter of what takes your fancy and what you can find. They really are much happier in groups of 6 or more.

I'm sure that would be big enough. I meant "bigger than is needed for true Corydoras". I wanted to be sure you knew the potential size of Brochis and that you allow for it when calculating your stocking rate.

As always, it's worth checking with SeriouslyFish :
http://www.seriouslyfish.com/species/brochis-splendens/

So having made a decision on what to get, I got all excited and made a trip to my LFS. They actually had everything on my list, except the snails (and judging by the tank, it was because they'd sold out by Sunday afternoon), so I spent a long time in the shop trying to decide which ones to get. My other pet fell asleep on the way over, so her dad sat in the car with her which meant I could ruminate unmolested.

In the end, I went for 6 more cardinals, 6 more harlies and a bristlenose plec. And walked away before I was tempted by any more. The harlies are actually a bit bigger than I thought, so hope that doesn't cause problems with water quality over the next few days. (Would it be acceptable to take a ruler to my LFS as I clearly can't estimate a fish' size).

The point of this post is that there are currently some very interesting behaviours in my tank. The new cardinals seemed to have just fitted in to the school, possibly because they are so much smaller than the existing fish. But there is some serious grandstanding going on amongst the harlies. I can't actually tell which are the new ones, but they would appear to be establishing their place in the school hierarchy. This will sort itself out without fatalities, I hope.

I'm also now a little worried about my single glowlight tetra. For years he has been behaving like a cardinal, but all the new company seems to have spooked him a bit. I guess it's a generation thing, he is about 100 in fish years (I've had him more than 4 years, and he was 6-18 months old when I rehomed him for a friend.)