Stocking/Filtration Question

[Flex26]

I have 5 albino tiger barbs, 2 'normal' tiger barbs, 1 rosy red in a 20gal high.

I was thinking about adding 3 'normal' tiger barbs (for a total of 10 tiger barbs). I also wanted to add 6-7 serpae tetras. I will probably take out the rosy red.

Potentially, I could have 16 or 17 fish in a 20galH. Now, I am running a Penguin 170 on my 20gal. Would this filter be enough for 16-17 fish? I was thinking that the 170 would not be enough. So, I was thinking about adding an AC mini or Penguin mini.

Would I be able to overstock a bit if I added more filtration and kept up with maintenance?

 

[wayne]

I doubt adding extra filtration will do you much good as you probably already have enough capacity between your filter, substrate, plants etc. to have the bacteria necessary. The main problem with overcrowding will be buildup of nitrate so you'll have to stay on the ball with water changes

 

[spikekillifish]

Filtration is only part of the equation. Stressed out fish is the other. Stick to the 1" of adult fish per gallon rule, its a good one.

 

[Luca]

Well, guidelines are guidelines, you can do what you want ultimately, the LFS definitely do not live by the 1 inch per gallon!!

You will have to be disciplined about water changes tho, every week or twice weekly is better.

 

[AndyL]

The LFS is also a completely different situation, just like feedlots for cattle. They're not something to measure against...

The 1" of fish per gallon rule is a pretty old rule actually. There is a lot more to it than 1" per gallon. "Since bala sharks get to 12" long, that means I can keep one forever in a 12g tank!" Doesn't really work does it, since balas need to be kept in groups and need room to swim...

C'mon there's a lot more to it than that... You've got to look at the system as a whole, and the individual fish in it to get a better idea if it can be done.

But as an answer to the original question, no you wouldn't be well advised to keep that many fish in a 20g tank. Even with daily water changes your fish would suffer...

 

[spikekillifish]

I tend to stay close to this old "rule" more for the fish and to prevent stress. Sure certain measures can be taken to handle larger bioloads, but I am quite content with sticking to the rule. Once one tank is stocked up its time to start another.

I wouldn't even keep a 12" fish in a 120G. tank. I prefer to keep more numbers of smaller fish and don't keep anything over 6" anymore.

I guess "rule" is the wrong term here as it is more of a guidline.

 

[madhippoz]

I have to agree with AndyL here. The 1 inch per 1 gallon leaves out a lot of important factors. Are they schooling/Shoaling fish? Are they active swimmers? Or do they stick to a certain "territory" within the tank. What level of the tank do they inhabit bottom/middle/top? Is their body form more horizontal like Colombians, or more vertical like Discus? Bio-load can't be guessed at all with the 1 inch per 1 gallon rule because you have no idea how much surface area of water there is for possible agitation, which is extremely important for over-stocked scenario's. Also, what environment does the fish live in? What "furniture" do you have in the tank for the fish, this all eats up how many actual gallons of water you have in the tank. A 10gal tank with rock caves and moderate planting does not provide 10gallons of water for fish to swim in, maybe more like 7 actual gallons of "water". It would be nice to have a simple rule of thumb to give to new aquarists, but its just not that simple. Tank space has to be measured differently for different types of fish.

Also agree with the LFS statement. LFS's overstock because they have too, in order to keep enough stock, in a pre-determined amount of space, to make a profit off of. I'm sure if you went to any of the LFS's employee's homes, their tanks would not be in those over-crowded conditions.

Look at my signature for my 34gal tank. That is a nicely stocked tank, I wouldn't want to add anything extra to it. I guess I just don't see the desire to want to overstock intentionally.

 

[spikekillifish]

It is a very effective "guidline" for beginers and even experienced hobbyists. Of cource there are exceptions to this guideline. Without this we would be just blindly guessing in most stocking cases as to our level of bioload. This guidline has been around and practiced by quite a few hobbyists like myself for a very good reason.

With this said rarley is this rule stated on its own. In most beginer articles on the subject, certain fish such as the ones you mentioned are said to be calculated differently. If you know you have 5 rummynose, 6 neons, etc.., and they are all an inch long it is safe to say that 11 Gallons of water is sufficient, anything less would be overcrowding. Without this guidline many inexperienced hobbyists would be lost.

 

[chompchompdie]

stocking depends almost entirely on the bio=load of the fish in question and the amount of work you are prepared to do. I have a heavily planted 33g tank with 16 Cardinal tetras, 16 Harlequin Rasboras, 6 Cories, 6 Rummy-Nosed Tetras a pair of Kribs and 3 Bosemani Rainbowfish. This puts the stocking level WAY above the 1 inch per gallon rule.

I perform a weekly 30-40% water change. The tank is filtered with a fluval 304 cannister filter. The plants also help keep the water clean. The tank has been up and running for just about a year and I have not had and problems with disease or death (i've lost 1 cory and 1 cardinal to krib breeding aggression, but thats it) the water parameters are always near to perfect. My fish are always fully colored-up, even the rummie nosed tetras, and they're considered by most people to be very sensitive to poor water quality. It can be done.

Having said that, I wouldn't want to stock a tank this heavily with messy fish (ie: cichlids) or if the tank was not planted. Regular water changes are also key.

 

[spikekillifish]

stocking depends almost entirely on the bio=load of the fish in question and the amount of work you are prepared to do. I have a heavily planted 33g tank with 16 Cardinal tetras, 16 Harlequin Rasboras, 6 Cories, 6 Rummy-Nosed Tetras a pair of Kribs and 3 Bosemani Rainbowfish. This puts the stocking level WAY above the 1 inch per gallon rule.

Lets face it, stocking is always going to depend on the individuals tastes, experience, etc,.... I prefer to allow my fish plenty of room and will continue to adhere to this guidline. Bioload is only part of the equation, many fish need the room to swim!!! I don't doubt that your fish look healthy. I myself would not stock that many fish in such a small tank, but thats just my experienced opinion. I myself used to over-stock quite abit. Now I look for a certain "Zen" balance in my tanks which may be hard to understand for some.

 

[madhippoz]

I didn't mean to imply one could not overstock. Plenty of evidence that it can be done as long as you're willing to do a little extra work. I guess I just follow the Spike line of reasoning where fish load is concerned, and go for a more modest stocking of fish.

Regarding the 1gallon/1inch rule. We seem to agree that it is an extreme over simplification. As long as an aquarist is made aware that its not a concrete rule, and that it varies quite a bit based upon each scenario then its an ok generalization of what you can get away with. I guess my concern is I've seen beginners misuse the rule before and have had to correct them. Hell, I even misused it myself the first time I heard it. For example most people don't base it upon adult, or near to adult fish sizes.

 

[Flex26]

Good points everyone. I think I'll bag the serpae tetra idea and just round out my tiger barbs to a total of 10.

Thanks for the input.

 

[chompchompdie]

Now I look for a certain "Zen" balance in my tanks which may be hard to understand for some

I agree....it was actually a disaster in one of my other tanks that caused the overstocking in the 33g (ever try netting all of your fish out of a leaky heavily planted aquarium?).

Obviously if you give fish more room you're gonna see more natural behaviour...preferable to a busy looking overstocked tank any day. I just brought it up as one extreme of what can be sucessfully accomplished....i'm not saying it's the ideal situation.