Which Stocking Rate Works Best?

[gwlee7]

I am somewhat confused concerning two different stocking rate calculations that I have read both in books and on various websites.

#1 is the basic 1 inch of fish per gallon of water that appears to be the consensus of the LFSs and alot of people on the net.

#2 is 1 inch of fish per 10 sq. inches of surface area of your tank. (for me that would be 48 x 13 = 624 or 62 inches of fish)


Which is correct in your experience? I realize that there are other variables too such as an angel fish being "more fish" at 5 inches than say a gourami at 5 inches because the angel is almost "square" in terms of length and width whereas the gourami would be more "rectangular" and therefore less mass.

The bottom line is that I have a 55 gallon tank that I DO NOT want to overcrowd. I want the most fish I can have but want them all to be happy. I have spent too much money getting ready for them to turn around and make them unhappy by putting too many in the tank. What I have so far is in my signature (fully grown they should total around 40 inches) and the next addition will be 6 - 8 pepper or bronze cories (another 12 - 16 inches). Will that be all for this tank?

Thanks in advance,

Greg

 

[Bignose]

You know, both these rules are just starting points. And I can debunk them very quickly. 20 1" fish can happily live in a 20 gallon tank, but one 20" fish cannot.

As you noted, it is mostly a function of the mass of the fish, but most of us don't have accurate ways of measuring the mass of our fish, so those rules would be best, but not really usable.

That said, I think a lot depends on your fish husbandry and plans, larger filters (a.k.a. overfiltering), an air stone or bubble wall, increased water changes, not overfeeding, and live plants all can increase the available bioload. Decreasing the surface agitation for CO2 injection, going long times between water changes, and poor caretaking lowers the available bioload. And to top it off, the gouramis dont add quite so much to the bioload as they get air from the top rather than primarily using thier gills to take oxygen out of the water, though my two are poo machines, so that goes against them. And, you have to make sure you buy fish that are compatible with one another -- if they are territorial or will fight with one another or otherwise incompatible that needs to be taken into consideration. Like, a red tail black shark likes to have a cave and a certain amount of tank area to call its own, so while he may only be a 6" fish, he will claim much more than 6 gal as his own.

So far, you have all fairly small fish, so you can probably add a school or even two of small peaceful fish like tetras, or another school of cory cats, or a few larger fish. If you have both sexes of your livebearers, you might be having a school of those sooner than you wanted .

In synopsis, no one rule or formula is going to fit all conditions. An awful lot of it really depends on how much upkeep you can and plan to do.

 

[yhbae]

Eventually, you will get the feel of the "right" stock level for each setup. When I started this hobby, I was after the ultimate formula that will give you the answer you seek, and I even created the Excel sheet that contains columns of data & formula based on tank surface area, (as mentioned already) mass of the fish, and their typical character (more active usually means they produce more waste).

But at the end, it isn't possible to generalize the approach that will work well with most species - too many special cases. It gives you some idea, but if you already successfully managed few tanks, then you would know that already even without this sheet.

If you are experienced, and are willing to filter more and willing to do more water changes, you can stock more heavily. Sometimes presence of plants help as well. (especially for reducing nitrates). Aggression/territorial behavior also plays a large factor in some cases.

For your info (whatever it is worth), just look at this stat of my tanks:

1. 30g: 0.8 inch / g (and going up fast!)
2. 25g: 0.9 inch / g (stable, all at near full size)
3. 15g: 2.7 inch / g (going up and down)
4. 10g: 1.3 inch / g (and going up fast!)
5. 5.5g: 5 inch / g (and going up fast!)
6. 5.5g: 0.7 inch /g (and going up fast!)

Filtration capacity:

1. 13 times per hour - planning to upgrade to 20x in few months (WC: weekly 30%)
2. 12 times (WC: weekly 30%)
3. no idea (AC200 (at least 13 times) + two sponge filters) (WC: 30% twice a week)
4. 23 times - just got upgraded (WC: 50% every two days)
5. 18 times (WC: 50% every two days)
6. 18 times (WC: 20% every two days, will eventually become 50% every two days)

As you can see, it is all over the place but all of the above tanks are doing great...

Personally, I don't like overstocking in community tanks. As you can see, I like to overfilter all of my tanks.

Wow, it was interesting to put up these (usuless) numbers together.

 

[gwlee7]

I don't have any live plants but I am running two aqua clear 300s on my 55 gallon tank. I had read that ten times gallons of tank per hour was the way to go as well as doing it with two filters in case of an emergency that one breaks down.

I want to be sucessful and can tell from reading this forum that the way to be sucessful is by being patient and by buying more tanks

After the cories have been added in a few more weeks I'll decide then if my particular set up will allow for more fish.

Thanks,

Greg