200L (48 gallon) Tank stocking advice

[Byron]

I would like another fish to add in as well, maybe the Bloodfin Tetra Or Giant Danio. I like the Buenos aires terta but I don't want my plants to get destroyed. Does anyone have a suggestion?

My only coment on this is to be careful, the Bloodfins are frequently fin nippers--environmental factors like the number in the group and tank size can affect this, as can other fish that may be less active though here you have relatively active species.

The plan will be to keep the tank at 20 C, although there will be some variation in summer as I live in Australia and my house gets quite hot but I have read that some variation to higher temperatures are fine, for these fish. I will make sure to keep watch on the tank in summer but I don't believe the temperature will vary that much it shouldn't go above 24 ish (if it does go to high I've already been reading up about cooling tanks with ice blocks or frequent water changes).

The temperature is a concern if it remains extreme (significantly low or high from the preferred) for long periods. Temporary heat waves are not as critical, especially if it cools down at night which is usually the case. My tanks rise during hot days, even with a room air conditioner they still get close to 80F from the normal 75-76F. This is usually not a problem. Feed less and maybe even omit some days if it is very warm (the water). Increased water temperature causes an increase in the metabolic rate, so the fish is then working harder to maintain the normal physiological functions and adding digestion when it isn't necessary doesn't help.

I personally would not advise temporary "cooling" measures like ice and/or frequent water changes because these result in more fluctuation within very short periods of time, and that is worse on the fish. Water heats more slowly than air, and obviously cools more slowly too, but this is much easier for the fish to manage that more frequent and significant changes. Turning the tank lighting off can avoid some heat onto the water, depending upon the type of lighting and if plants are present; for the latter, reducing the photoperiod may be possible. However, changes in the lighting also affect fish, so it is perhaps a trade-off and you might as well leave the light normal.

Byron.

 

[Ch4rlie]

Just going to add my 2 cents worth.

You mentioned earlier you may plan to have :

x7 Zebra Danios
x7 Lepoard Danios

I have kept several species of danios in the past and currently keep Celestial pearls and Emeralds in separate tanks.

My advice would be is just having one specie of danio rather than 2 species, simply because with danios the larger the group, the happier the danios will be.

I did originally have only 6x of each current species and they were okayish, very skittish and hid behind plants in one particular corner of the tank a lot. When I later added 12 more of each, their behaviour changed dramatically and were much, much more confident, not so skittish and easily spooked which can have detrimental affects on their health. I was surprised but at the same time makes a lot of sense since danios are not the largest of fish species so more easily intimidated.

So if you want danios to thrive and display more natural behaviours, I'd suggest at least 15+ of one specie.

As for all the other's advice, all very good and definitely worth taking into consideration.

We all learn something here

 

[Essjay]

Charlie, do you mean you had both zebra and leopard danios in the same tank? The reason I ask is because Seriously Fish says that leopard danios and zebra danios are just different colour morphs of the same species, not separate species as used to be thought.
If you do mean you had both together, did the two colour forms mix at all?

 

[Ch4rlie]

No, separate tanks as wanted variety between the tanks is all.

Never tried to breed any fish so no idea if the two would breed or what the offsprings colourations would be. Quite an interesting thought really.

 

[Essjay]

So, in theory, the suggested 7 zebra danios and 7 leopard danios should behave like one shoal of 14 danios of mixed colours.

 

[Ch4rlie]

Hmm, for the most part, yes I think so when comes to behaviour and compatibility but personally I tend to keep just one larger shoal of the same specie despite these danios are pretty much the same but with having colour morphs differences.

That's just my preference to keep things much simpler especially if you want to breed from them as results will probably be mixed and not consistent and may even result in weaker strains, though am not a breeder so that's not a given, just my hypothesis really.

 

[Byron]

So, in theory, the suggested 7 zebra danios and 7 leopard danios should behave like one shoal of 14 danios of mixed colours.

Probably, yes, since it is generally believed that these two "species" are in fact conspecific. The leopard danio, sometimes seen under the name Danio frankei, is probably a man-made colour morph variation of the Zebra, Danio rerio; most authorities agree that this variant has not been found in nature. Fish "varieties" that are so closely related genetically seem to regard one another as the same, so far as we are able to ascertain from their behaviours.

Charlie raises a good point about breeding though. Responsible aquarists in the hobby take care not to release hybrids into the hobby, unless specifically developed and explained as such. So any cross-hybrid fry that might result from a spawning of two varieties should not be sold/given to others, as these may well end up in the hobby. There are other considerations to this of course, such as fertility, etc, but generally the view is, don't do it.

Edit. I see you already referenced the conspecific issue, I typed my post before reading earlier posts...no matter.