Overstocked? Final Thoughts On My 20 Gal....

[Noahsfish]

So in my 20 gallon this is what I currently have.
X4 sterbai corydoras
X1 schwartzi corydoras
X3 cardinal tetra
X1 opaline gourami
X 1 dalmation Molly
X1 betta.

I know I'm poorly and possibly overstocked as far as compatibility and schools go. In a few days Ill be adding my betta to the 10g, and possibly getting a couple more cardinals. My question is, is should I upgrade filters? I right now have a aqueon quiet flow 20, as generic as you can get...I was thinking of maybe going for a fluval canister? If you guys think that's a good idea, would you mind recommending a specific model of the canister. Ok, I also want to eventually move the Molly and gourami to a larger tank, and wanted to replace them with another few fish. So ideally within a couple months this is what I want
X5-6 cardinal tetras
X4 sterbai corydoras
X1 schwartzi corydoras
X2 German blue ram.

Are either of these two setups overstocked? My current or future? And should I upgrade filter? I was thinking of getting another smaller aqueon filter and yeah...

 

[Blondielovesfish]

Not sure about the filters but a way to see if the tank is overstocked is to use the rule of 1 inch of fish per gallon, just search the adult size of the fish you're looking at on google and go from there!

 

[techen]

I would say yes to being overstocked.

6 corys and 6 tetras is where I would be in a 20gal.

 

[the_lock_man]

You're obviously aware of the ideals of shoal sizes, and happy to go the way you want to go, so I'm not going to sit here preaching at you. What I would suggest, though, is to put the Schwartzii in the bigger tank with the molly and the gourami, and get 2 extra Sterbai. Again, I'm not saying this is ideal, but to my mind, it's a slightly better compromise than what you are proposing.

 

[r.w.girard]

I feel like I keep saying this in every post I make... which is depressing and more a statement about me than anything else,  but it all depends on the footprint of your tank: if you have a 20L, 30"x12", you should be able to happily house a small school of tetras, one shoal of corydoras and a breeding pair of rams, bolivian or german, depending on water chemistry, temp, etc.
 
That said, if it is a normal 20, which only has a 24"x12" footprint, there will not be enough room for all of the above, because both corydoras and rams occupy the bottom level and rams can be quite territorial when breeding, which would lead to undue stress to your corydoras, regardless of their stocking level. So then pick one or the other, but still only one shoal of corydoras.
 
In both cases, however, if you are going to attempt this, you should probably upgrade to a larger, canister filter.  Is your tank planted?  If so, I have an Eheim 2217 on my densely planted 20L and I love it.  I run it at full down the length of my tank.  Of course, you couldn't do something like that until after the betta and possibly the gourami are out of the tank.

 

[Jenste]

Not sure about the filters but a way to see if the tank is overstocked is to use the rule of 1 inch of fish per gallon, just search the adult size of the fish you're looking at on google and go from there!

This is an old gimmick rule that doesn't really work outside of fish larger than neons. Example - a 10 inch oscar would never work in a 10 gallon tank.

You should stick to one type of corydoras and one school of tetra.

 

[Lunar Jetman]

Not sure about the filters but a way to see if the tank is overstocked is to use the rule of 1 inch of fish per gallon, just search the adult size of the fish you're looking at on google and go from there!

This is an old gimmick rule that doesn't really work outside of fish larger than neons. Example - a 10 inch oscar would never work in a 10 gallon tank.You should stick to one type of corydoras and one school of tetra.

I see what you're saying but for beginners this is a decent enough rule to stick to. Yes, there are extra rules for bigger fish but I think you need to have something to work to if you are just starting out.

 

[dgwebster]

Not sure about the filters but a way to see if the tank is overstocked is to use the rule of 1 inch of fish per gallon, just search the adult size of the fish you're looking at on google and go from there!

This is an old gimmick rule that doesn't really work outside of fish larger than neons. Example - a 10 inch oscar would never work in a 10 gallon tank.You should stick to one type of corydoras and one school of tetra.

I see what you're saying but for beginners this is a decent enough rule to stick to. Yes, there are extra rules for bigger fish but I think you need to have something to work to if you are just starting out.

An old book of mines says:

A surface area of 1800cm2 can support four 15cm catfish, or one of 60cm

Fantastic. It does cover the coldwater/tropical/marine difference and surface area challenges and why you cant use 1" per gallon.

As many have said, there is no "rule" that can be used. Starters tend to be more about slender less messy small fish so the surface area is a decent starting point but its really this: if you are asking others if its overstocked, it probably is.

 

[Lunar Jetman]

if you are asking others if its overstocked, it probably is.

Exactly....

 

[cpwebsite]

X4 sterbai corydoras
X1 schwartzi corydoras
X3 cardinal tetra
X1 opaline gourami
X 1 dalmation Molly
X1 betta.
 
Take out your betta, molly, and gourami. Then increase your number of cardinal tetras to 6 or maybe all the way to 8.

 

[Ruskull]

I would say yes to being overstocked.

6 corys and 6 tetras is where I would be in a 20gal.

 
 
C'mon now, that's ridiculously understocked bro.  It would depend on what Tetra & what Cory also.  I admit my 20 gallon is overstocked, but I'd say 8 Corries & 8 to 12 Tetras plus a centerpiece fish such as a Swordtail, Platy, etc.  Maybe even a trio of either of those.

 

[Lunar Jetman]

I would say yes to being overstocked.

6 corys and 6 tetras is where I would be in a 20gal.

 
 
C'mon now, that's ridiculously understocked bro.  It would depend on what Tetra & what Cory also.  I admit my 20 gallon is overstocked, but I'd say 8 Corries & 8 to 12 Tetras plus a centerpiece fish such as a Swordtail, Platy, etc.  Maybe even a trio of either of those.

Sorry, I'm with Techen on this. Most Corys get up to 2 inches fairly guickly so by your plans you'd have 16 inches of Corys in a 20 gallon tank plus a minimum of 12 inches of tetra. That's 28 inches before you even think about swordtails, platies, etc.

You need to think of the adult size of the fish not the size you get it!

 

[Ruskull]

So basically you're saying 6 Neons & 6 Corys are all that you'd keep in a 20 gallon?  More power to you.then.  I've had my Threelined Corries for around a year and they're only 1.5 inches at the largest.  The inch per gallon rule is practically useless in my opinion.  

 

[Noahsfish]

Well for the tetras and cories as I previously said they're cardinals and sterbais. Yes, the tank is planted I have java moss, java fern, anubias, cabomba, wisteria, amazon sword, and 5 marimo moss balls. I have some malysian dw and 3 watts per g. Sorry I haven't replied to some of your guys suggestions, I really appreciate it. As it stands this is what I have in the 20 gallon.

X6 cardinal tetras
X6 sterbai corydoras
And soon 1-2 German blue rams

The betta is in my ten, and the gourami and Molly are cycling my new 30gallon.
So some people are saying 6 cardinals and 6 sterbais is perfectly stocked, should I stay away from the gbr? That's what I'd been planning on for my centerpiece..

 

[JenJ]

I would say yes to being overstocked.

6 corys and 6 tetras is where I would be in a 20gal.

 
 
C'mon now, that's ridiculously understocked bro.  It would depend on what Tetra & what Cory also.  I admit my 20 gallon is overstocked, but I'd say 8 Corries & 8 to 12 Tetras plus a centerpiece fish such as a Swordtail, Platy, etc.  Maybe even a trio of either of those.

Goodness, that's more than I've got in my 40 gallon! And I wouldn't put much more in there...
 

Well for the tetras and cories as I previously said they're cardinals and sterbais. Yes, the tank is planted I have java moss, java fern, anubias, cabomba, wisteria, amazon sword, and 5 marimo moss balls. I have some malysian dw and 3 watts per g. Sorry I haven't replied to some of your guys suggestions, I really appreciate it. As it stands this is what I have in the 20 gallon.

X6 cardinal tetras
X6 sterbai corydoras
And soon 1-2 German blue rams

The betta is in my ten, and the gourami and Molly are cycling my new 30gallon.
So some people are saying 6 cardinals and 6 sterbais is perfectly stocked, should I stay away from the gbr? That's what I'd been planning on for my centerpiece..

As the cardinals are one of the slimmer, smaller tetras, I think you could get away with having the ram in there too. I'd stick with the one though.
 
Picking up from your other thread, not sure what plans you have for your 30, but if you put your gourami and molly in there, you could add your harlequins in and probably double the group size - a nice big group of harlequins would probably school beautifully in there