My stocking list for 20gal long

[Satsumas]

I am thinking about fish for my 20gal long and my current stocking list looks like this...

8 rummy nose tetra
5 julli or panda cory
3 dwarf cockatoo cichlids

My calculations make that 35" of fish, now following the 1 inch of fish to every 1 gallon of water rule makes that about 15" over the limit!
However i hear that this rule isn't always a great one to follow?

I have just recieved my Fluval 205 filter which is more than capable of filtering this tank which will aid me greatly in keeping good quality water.
Also i plan on getting about 3wpg of lighting and heavily planting this tank which would also help with the water chemisty.

Also looking at the balance of fish over the tank and it seems fine.
The rummy nose's would be mostly at the top, the cockatoo's would be all over the tank although they may be more bottom dwellers?, with the cories at the bottom.

Are there any possible changes that i should consider or any thoughts/suggestions that i should consider?

TIA.

EDIT
Just came accross this.
"They are fairly aggressive fish (dwarf cockatoo's), but do fine in community tanks. The only fish I had problems with are cory catfish, they take up the same tank 'zone' and will be attacked. I lost one cory, and removed the others."

 

[severum mama]

I haven't kept a. cacatuoides, but I would imagine that they will stay mostly in the bottom half of the tank, much like GBRs, Bolivian rams, or my a. steindachneri. I'd be surprised if a. cacatuoides would pay much attention to corys unless they are spawning. A 20 gallon wouldn't afford their tankmates much space to get away.

I tend to overstock my tanks but am careful to choose fish that occupy different strata in the tank. In your case I would rethink the rummynose tetras, or the corys, or both. I keep rummynose tetras, and they stay almost exclusively in the bottom half of my tank- in fact, it took them months before they were comfortable enough to approach the surface for food. That's a lot of fish in the bottom half of your tank confined to only 20 gallons. There are lots of other tetras you could choose that would swim all over your tank. JMO.

 

[bs6749]

In my opinion, it isn't a matter of filtration that limits the amount of fish in an aquarium. Yes, filtration is important, probably the SECOND most important part. The MOST important part is the amount of space for the fish. You could put 12 people in an elevator with adequate ventilation but would any of the 12 people really want to be in there very long? Remember that you will cause your fish stress which will shorten their lives and make them less healthy when you are overcrowded. Not saying that you are or aren't but you should also remember that substrate, plants, decorations, and equipment also take up room in the tank. A 20 gallon may be more like 17 after you are done with everything and this would mean that you have TWICE the amount of fish in there that you should have. I think that amount listed would be fine though.

 

[Shubunkin01]

I thought that the surface area of the tank was more important, as this was how the fish get their oxygen. Air pumps help, but the only way they aerate the tank is by agitating the surface of the water. The bubbles don't actually stay in the water long enought for the oxygen in them to dissolve.
If you take the length of your tank and multiply it by the width, then this is your surface area. Tropical fish need 75 square centimeters or 12 square inches for every inch or centimetre long they are. So a 10 cm fish needs 10x15=750cm squared of surface area.

Hope that helps
Shubunkin01

 

[Satsumas]

I would like to think that the list is about right, but that is providing that the cories stay on the bottom, the rummy nose's or smaler fish stay together in a school at the top and the apisto's go all over. I don't think that will be the case though, i have black neons and danio's that don't seem to know what a school is. I think school's can look really spectacular in planted tanks with dark substrate and a dark background. I'd like a tight school severum

"To determine roughly how many fish your tank can hold, first multiply the length of the top two edges together to give you the surface area of your tank (length x width). You should aim to have no more than 1 inch of fish for every 10 square inches of surface area.

For example, a tank that measures 36 x 15 inches has a water surface area of 540 square inches. Dividing 540 by 10 produces a total recommended fish length of 54 inches."

My tank measures 36" accross the front, 12 deep (back to front) and 14.5 high.
36"x12" = 432" Then i have to divide 432 by 10 which makes 43.2
Following this rule i am fine with the current stocking.

(Info and calculations taken from http://www.pnl.gov/ecology/Rivers/Aquarium/Aqua.html)

This tank is still very much open for change with regards to stocking so please feel free to throw ideas and suggestions at me.

Thanks for the replies

 

[JustOneMore20]

I personally think you'll be fine with that stocking. My Rummynose tetras stay in the middle area mostly. At night they stay towards the bottom, but thats when they are sleeping. During the day they are in the middle. The Apistos shouldn't bother the cories. I've never heard of them having problems with other bottom dwellers like cories and loaches.

I tend to overstock my tanks too, so I think you'll be fine. Having a heavily planted tank definitely helps with the bioload.

I think you will love the Rummynose tetras. They are the best and tightest schoolers I've seen.

 

[severum mama]

I would like to think that the list is about right, but that is providing that the cories stay on the bottom, the rummy nose's or smaler fish stay together in a school at the top and the apisto's go all over.

I don't think that your tank would be horrendously overstocked or anything, provided that you keep up on pwc's and have good filtration, but I am speaking from experience here that apistos will tend to stay toward the bottom of the tank, and rummynose tetras will as well. I just think that's too many fish for one area of your tank. If this were a 50 gallon or something there would be no problem at all, but apistos, corys, and rummynose will practically be running into each other in a 20 gallon. I just think your fish would be more comfortable if you chose a schooling fish that didn't stick so close to the bottom all the time. Unfortunately, no tetra species come to mind that will school as tightly as the rummynose. If you really want the rummynose, you could go with a small pleco for your bottom feeder. That would at least reduce the activity at the bottom of your tank. JMO

 

[Satsumas]

Yeah if the rummynose stick close to the bottom then i will have a problem.
I am a little worried by the comment i read about the apisto's picking on the cories which show's some territory issues no doubt? Also if the tank is small like mine then this will surely be more of a problem.

I do want a semi-aggressive fish that will keep smaller fish in a school at the top of the tank, i was hoping that some apisto's would do that but now i am not so confident.
I like the sound and look of the rummynose but i am mainly after a brightly coloured, tight school of small top dwellers, not necessarily a tetra species.
I read up on the rummynose and read some comments about them on here which got my interest.

I do however really want to keep cories! They are my main fish that i haven't even thought about reconsidering I do have 2 pleco's in my other 20gal so i may move my BN accross but i haven't really thought about it yet. It does seem the sensible thing to do though.

 

[JustOneMore20]

How about Harlequin rasboras? Mine stay mostly in the middle area, sometimes near the top. They are very boldly colored (irridescent red) and beautiful IMO.

 

[severum mama]

Harlequin rasboras are great! Mine stay mostly at the top/middle of my tank and they are very pretty fish.

 

[Satsumas]

I am open for most small fish as long as they are top dwellers and school!
I am quite surprised that most tetra's and in general smaller fish that should school don't tend to in aquariums.
I think harlquin's are nice but i haven't looked at them with a view to actually getting some, i'll have to have a thorough look next time i go to my LFS.

I like the look and sound of keyhole cichlids as apposed to apisto's.
They need hiding places which may be a small problem as my tank isn't very deep. I can manage 3 or 4 no real problems but how many hiding spots will the cories require? I suppose the more there are the safer the cories and other fish that require them will feel.

EDIT: I am liking the look of the purple emporer tetra, how would having 10 fair in my tank with possible keyhole's or apisto's? Should be fine i am thinking but it's best to ask on here first i think.

 

[severum mama]

Interesting you mentioned the purple emperor tetra; I've wanted to try keeping some since I saw them on LiveAquaria, but have never been able to find any locally. They appear to be peaceful and relatively small, so you should be fine keeping them if you can find them.

Keyholes are great fish, but they do grow a bit larger and bulkier than apistos, so they may be more of a strain on the tank's bio filter than the smaller apistos. I would suggest no more than 2. JMO

 

[Satsumas]

I also can't seem to find any purple emporer's locally, but i've only seen them here... http://www.tropicalfish4u.co.uk/acatalog/Purple_Emperor_Tetra.html I've never bought fish online but i've read their postage and shipping details and they seem like they know what there doing. I still personally don't like the idea but my LFS only has the most common fish in stock and i've seen plenty of fish that i haven't seen before on that site.

Keyhole's are interesting and i was thinking getting just the 2 hopefully a m/f pairing.
I hear that they are difficult to tell apart but are good parents and they can sometimes form a strong bond with each other which would be nice to see.

if i look at 8 purple emporer's at 1.5" that's 12" of fish.
2 Keyhole's at 5" each that's 10"
5 Panda, julli or schwartz's cory's (can't yet decide) 2" each that's 10"

In total that's 32" of fish. Going by the calculations i found (8 posts up) then i am about 10" of fish understocked. Overall how do you see that choice of fish fairing in my tank?
The tank will have eco complete substrate, CO2 injection and i'm going to have a go at heavily planting the tank aswell.

 

[severum mama]

The keyholes will probably not reach 5 inches in the aquarium, and if you stick with panda corys they will likely remain under 2 inches.

 

[ezy33]

I thought that the surface area of the tank was more important, as this was how the fish get their oxygen. Air pumps help, but the only way they aerate the tank is by agitating the surface of the water. The bubbles don't actually stay in the water long enought for the oxygen in them to dissolve.
If you take the length of your tank and multiply it by the width, then this is your surface area. Tropical fish need 75 square centimeters or 12 square inches for every inch or centimetre long they are. So a 10 cm fish needs 10x15=750cm squared of surface area.

Hope that helps
Shubunkin01

Well stated. During a power outage or pump failure is when overcrowding will be stressful for the fish.

 

[Satsumas]

That's strange severum :?

I would like them to be my 'fish that keeps the school on their toes' and obviously if they were a bit larger they would be more of a presence.
I would also like them to be the biggest fish in the tank, i'd consider it 'their' tank aswell as i would like to think they would feel relaxed and at ease. Under 2 inches! That is really small! the emporer's would look a similair size! I was hoping for 4 inches minimum!

So why will the cories limit or stunt their growth?

 

[severum mama]

I meant that panda corys will stay under 2 inches in the aquarium. When I look back at my choice of wording, I can see how it was confusing. Sorry, lol. The keyholes will likely grow from 3.5-4.5 inches, but it is doubtful they will reach 5. If the keyholes start to seem crowded as they grow, you may need to return one or upgrade the tank. I'm growing out 3 small juveniles in my 29 gallon right now, but I have plans to upgrade them when necessary. The sources I've read say that they are slow growers, so I'll have time to work everything out for the upgrade to a 55.

 

[Satsumas]

Oh right, now i read it again i realise what you meant lol.

Hmm, the only fish i am decided on at the moment is cories!
Saying that i am into loaches and some dwarf chain's or generally smaller loaches would be good
I do think i'll stick with the cories though, i've got yoyo's and i want to experiment with different types of fish.

I do have a while to think about fish though so there is no point in rushing and i really want to get it right. I have to plant the tank up first and get aquascaping!