Calculating safe Bioload levels

[ourmanflint]

hi there..

In answer to many threads here re: how many fish can i keep in such and such size aquarium etc... I thought it would be a good idea if those of us ( and by that I mostly mean you all) tried to pin down just which is the best way to work out how many fish and inverts etc a given volume can support.
I'm sure all of us here have a pretty good idea ourselves when setting up a tank just how many fish we can safely squeeze in without worrying about loss of water quality, but this always seems to be a case of judgement.... do 10 neons = 1 Betta splendens = 25 boraras etc...

For myself I use the old addage of 1" fish for every 12 sq" surface area of tank as a guide, but then translate that into a weight of combined biomass. eg in a 2ft tank...
20 x 1" platy for example do not have same wasteload as 20 x1" Neons for example... more like 30-35 Neons, and 1 Neon has roughly same mass as 2-3 Boraras sp. minimum etc...

How do you work out your bioload capacities?

[nostalgia]

I'm curious to know too! Anyone can share info on it? Am I overcrowding my tank? Have got >100 Malayan Shrimps, 49 Rummy Nose, 3 Cardinal, 5 Pencil fish, 6 Yamato Shrimps, 4 Otos, 2 Panda Corys, 1 Cigar Fish all in my 3 ft planted tank.

[|squee|]

Imho, it's all about personal opinion. I've read about people who claim they've suceeded keeping 100 tetras in a 2ft (16 gallon) tank. Yet common sense tells me that above 30 is already pushing it. I'll go even lesser for a planted tank, about less than 15 if they were tetra-sized. It's for personal preference.

For fish-only tanks, it's of course okay to go to about 30 or so imho. nostalgia, imho your bioload is fine. Just sit down and look at the tank, if you feel that fish are cramped, it's usually cramped.

[guan]

haha.. 200 tetra in a 2ft tanks sounds terrible. but i had got this experiences that putting 200 tetra in a 2.5 ft tank, and they left with only 30 of them within one month.
thus i think it would be alright to add few pcs at each time, to prevent shock to the fish.

[vinz]

I'm curious to know too! Anyone can share info on it? Am I overcrowding my tank? Have got >100 Malayan Shrimps, 49 Rummy Nose, 3 Cardinal, 5 Pencil fish, 6 Yamato Shrimps, 4 Otos, 2 Panda Corys, 1 Cigar Fish all in my 3 ft planted tank.

Note though, that a 3'x2'x2' tank is about 1.8 times larger then 3'x1.5'x1.5' tank in terms of volume. So that means you can almost double the bioload.

So which is it?

[vinz]

Flint, seems like not many people have answers to your question. I think most go by estimation, like squee. So do I.

Going along your train of thought... I used to keep an arowana... and even at 6 inches in length, it's way way above the bio-load of six 1 inch tetras.

[nostalgia]

Note though, that a 3'x2'x2' tank is about 1.8 times larger then 3'x1.5'x1.5' tank in terms of volume. So that means you can almost double the bioload.

So which is it?

Thanks bros for the replies. Mine is just a 3'x1.5'x1.5'. Recently I note that my fishes are gasping for air in the morning... even thou i off the CO2 at nite.... why is this so? I'm quite concern as they have only recently started to do such things. Previously for over a month plus, there was't any of such things happening...

No need plants nor fishes were added during this period but instead had a few fishes dying. Another thing to add is that I've add medication for white spots as some rummy nose had white spots on them.

[muakmuak]

hope your white spot is gone by now..

i am also clueless to estimate how much bioload for 4x1.5x2 tank. is there any guidelines?

[nostalgia]

hope your white spot is gone by now..

i am also clueless to estimate how much bioload for 4x1.5x2 tank. is there any guidelines?

Nah, I don't have white spots! Most of the white spots on the rummy nose tetras are cleared. There is still 1 with a couple of white spots on it's fin while my SAE still has white spots....

[bclee]

Thanks bros for the replies. Mine is just a 3'x1.5'x1.5'. Recently I note that my fishes are gasping for air in the morning... even thou i off the CO2 at nite.... why is this so? I'm quite concern as they have only recently started to do such things. Previously for over a month plus, there was't any of such things happening...

No need plants nor fishes were added during this period but instead had a few fishes dying. Another thing to add is that I've add medication for white spots as some rummy nose had white spots on them.

Maybe it is time to clean your filter. Stuff decaying in the filter will consume O2.

You can also introduce a little surface movement. It will help the gas exhange during the night.

The temperature is starting to rise recently. The will means lower O2 in the water and also higher metabolism. Temperature could be a factor also.

BC

[nostalgia]

Maybe it is time to clean your filter. Stuff decaying in the filter will consume O2.

You can also introduce a little surface movement. It will help the gas exhange during the night.

The temperature is starting to rise recently. The will means lower O2 in the water and also higher metabolism. Temperature could be a factor also.

BC

oh okies! I'll tilt my rainbar upwards to create water movements. Have not cleaned my filter in 2 months.... exams and deadlines are cramming into my schedule.... Will clean it on sat morning then!

Thanks for the advice!

[celticfish]

i'd like to add another point.

volume of water and frquency of water change also affects the bioload.
more volume equates to more ammonia/waste holding capacity.
frequency of water change also contributes to lowering ammonia/waste levels.

ammonia/waste affects fish growth. they may not die on you but their ability to achieve their full potential is stopped. the fish basically gets stunted. you will probably be tasked to see the difference in small fishes like tetras but it'll be very obvious for fish like discus.