Stock Levels

[moeldner]

I know there is a lot of information out there about stick levels, but I am very new to tropical fish keeping, and would like a definitive answer that I'm hoping the experienced people here can provide.

I have a 120L (32 US Gallon) tank (dimensions-approx 68lx38dx48h cm)that I have started stocking. On advice from the LFS, I plan on having the following in it:

2 x Discus
8-10 x Ottos
10 x Cardinal Tetras
10 x Harlequin Rasbora's
6 x McCulloch's Rainbow
1 x Bristlenose Catfish

and potentially some more zebra danios (currently have 1)

The tank is planted with a gravel substrate. I have a filter hanging on the side of the tank, and a large airstone oxygenating the water. I plan on having a healthy volume of plants in the tank as well. Current temp is 29 C, but it will be increased to 30C in the next few days to start acclimitising the current fish before getting the discus (again on advice from the LFS).

My question is simply this - is this too much?

I have started stocking the tank (mostly with fish that came with the tank second hand) and currently have the following in it

3 x Cardinal Tetras
3 x Harlequin Rasbora's
6 x McCulloch's Rainbow
1 x Bristlenose Catfish
1 x Zebra Danio

I am treating the tank for a bacterial infection the catish appears to have, so nothing will be added for a few weeks yet (until the catfish appears well).


Thanks in advance.

 

[dwarfgourami]

Sorry to be the bearer of bad news, but your plan sounds like serious overstocking.

Discus grow large (6-10 inches) and require very good water stats; they are not recommended for beginners for this reason as they are sensitive, and they should certainly not be kept in a smallish overstocked tank. I would leave them out of the equation altogether and work with the fish you have.

Not sure how big the rainbows grow but am assuming they'll get up to about 4 inches. So that's 24 inches there, plus 4 for the bristlenose= 28+ roughly 9 inches for your current tetras and rasboras= 36+ 2 for your danio= 38. This leaves you slightly overstocked already, unless I have overestimated the rainbows. I am making a rough calculation using the inch of fish/gallon rule; note that this does not apply to large-bodied fish like discus.

I would therefore also forego the ottos- unless you are prepared to get rid of the bristlenose. (Also, otos are slightly more sensitive to bad water, so do not do well in a new tank).

Next question, is the tank cycled? How long has it been up and running, how did you introduce your fish? What are your water stats for ammonia and nitrite? Any problem there could explain your bristlenose's infection. Test the water and send us the stats. First of all you need to make sure that your tank is in working condition (bacteria present, filter able to cope)- before you are absolutely sure, you should not be thinking of adding more fish. Are you doing regular water changes?

When all this is sorted, ideally the rasboras, danios and tetras do need to be in bigger shoals, but I don't think you will have room for 3 big shoals in there. So I would rehome two of those species and buy some more of one.

 

[Purplesmurf]

Quite the montage of fish there.

No discus. Especially in a tank that low. Generally speaking your tank needs to be shaped similar to your fish. Long, thin fish, like loaches, danios, or, as an extreme example, twig catfish need room to turn around and swim back and fourth. The boxier the fish the more vertical room it needs. This is where discus first become a problem as tanks shaped to suit them are hard to come by or custom built. Personally I wouldn't reccomend housing them in anything less than an 80gal high (48 7/8 x 14 x 30 3/4).

For you they'll end up being nothing more than pretty bodies.

The harlequins are a good choice. A little finicky when acclimating, but hardy after established in a tank.

Ottos are fun... but personally I'd forget about them and aim for a larger fish. You have the room so why not invest in something a little more outstanding sizewise? Think about waiting several months to let the cardinals grow out and then add juvenile angels. The predetory nature of the angels will tighten up the harlequin and cardinal shoals but neither will be in an real danger as a full grow cardinal/harlequin is too big to be eaten by a captive raised angel.

Otherwise I'd say you have a good setup.

 

[Cheese Specialist]

Very overstocked IMO.

As said, discus need high tanks and a lot of water. They become huge (I got a fright when I met the parents of discus I was buying once ) and simply won't fit in that tank.

8-10 otos is a bit much IMO. For that size tank 4-6 would be a better idea. Although they are small fish, they are plecs and they poo quite a lot for their size. They'll also be competing for food with the bristlenose that's on your list.

The bristlenose will be fine as long as you make sure there's some wood in the tank. They need food as part of their diet and also for shelter during the day.

I do not follow inch per gallon rules (nonsense things in my opinion) but I do look at how many fish you have in one area, the nature of the fish and so on. You need a good balance of upper, middle and bottom dwelling fish as although a tank may not be technically overstocked, it can be overcrowded in an area. You have too many middle/upper shoaling fish planned.

Also, you need to look at how compatible the fish are. Discus and rinbows are not. Rainbow fish swim too far and too fast and would stress discus out, as they will cardinal tetra.

HTH

 

[moeldner]

Thanks - appreciate the feedback.

As I have been treating the catfish, the filter medium has been out of this tank for a couple of days. The cat fish's infection has completely dissapeared, but I will be monitoring him to make sure that the wound on his belly is healing OK.

I tested the water tonight, and Ammonia and Nitrate levels are 0, Nitrite is 10ppm. I'm expecting this to drop in the next 24 hours, as the filter medium is now back in the tank. I'm not sure of the treatment for the catfish is affecting these tests though.

Originally we were planing the following

2 x Discus
4-6 x Ottos (2-3 were going to go in the betta tank - forgot about this earlier )
10 x Cardinal Tetras
6 x McCulloch's Rainbow

But based on what all of you are saying, even this is too much.

The rasbora's, danio and the bristlenose came with the tank, so we may have to rethink our plans, or rehome them to another tank.

The rainbows shouldn't get over 2.5 inches, so the total I have so far shouldn't exceed 30 inches (getting close on the inch per gallon rule though).

The water is very well aerated though, so I should have a little flexibility in this I think. (please advise if my thoughts are incorrect on this)

Is there something else that we may be able to use as a feature fish someone can recommend? Some of the more placid gourami's for example

Thanks again for your advice.

 

[@ombomb]

The water is very well aerated though, so I should have a little flexibility in this I think.

Stocking levels in a tank aren’t really based on the aeration of the water, but the biological load on your filter. The more fish you have, the more waste there is in the tank, the more ammonia / nitrites your bacteria have to deal with.

As has been said, Discuses are not for beginners as they require the most pristine water conditions, which are very difficult to maintain, particularly without using reverse osmosis for your water and definitely not in an overstocked tank.

 

[moeldner]

Thanks @ombomb. I'm convinced, but I also need to convince the boss that this is not the way to go for now. SHe had her heart set on a pair of Discuses.

I'll have to think about what I want to do now.

Appreciate the advice from all.

 

[pica_nuttalli]

well, if you need additional reasons to not mix in the discus... bristlenoses and the rainbow fish really shouldn't be kept above 28C; otos, true harlequins and zebra danios don't thrive above 25C. i'm not certain on cardinals, but the rest of your fish would slowly boil themselves in the current tank setup. dropping the temperature down to 27C or so would probably be a good idea (i've seen discus as liking a 26-30C range)

there are any number of beautiful captive angel lines that would help satisfy the boss lady such as blushing, calico, koi, or gold. pearl or moonlight gouramis are also stunning; for a bit of strong color, check out the gold gouramis.

additionally, there are a number of bottom-dwelling dwarf cichlids that you could check out--search for "apistogramma" to find sites with galleries to look around in. most of the dwarf cichlids can be bred in the home aquaria without decimating the rest of your stock and breeding behavior always spices up the appearance of a tank.

 

[Cheese Specialist]

the filter medium has been out of this tank for a couple of days.

Errrrrrr

All of the media or just the wool? If the former, uh-oh.

 

[Snailguy101]

Yes that is over stocked

 

[Ethos]

I'd say just drop the discus. When I wasd wanting one one these, I read that they are very, very unforgiving, and for the begginer, should only be a species tank.

 

[moeldner]

the filter medium has been out of this tank for a couple of days.

Errrrrrr

All of the media or just the wool? If the former, uh-oh.

Had no choice - had to be the wool and the carbon - it's together in a single cartridge.

I kept the filter medium in tank water while it was out, and was keeping a close eye on the fish, so I think it should be alright. I'll be testing the water again very soom to make sure nothing is spiking.

I also performed a 25% water change last night (as instructed on the treatment bottle, so I'm just following the instructions on the label.

 

[masterfishes]

anybody correct me if im wrong....but i would drop the discus and the bristlenose cat and go with
3-5 otos
5-7 each of the danios, rasboras, and and the tetras
and a couple of rainbows.....if they have to be in a school then id say around 5