Formulae for Fish Capacity

Hey folks,

I thought it might make an interesting discussion for seeing how each of you works out how many fish can be kept in a specific tank??

I have heard several different methods for working the tanks 'Fish Capacity' out, but wanted to hear yours...

Obviously these would all be rough estimates, as different sized fish produce different ammounts of waste, for instance, one Oscar will produce far more poop than his equivalent length in neons or guppys (especially after hes eaten them! lol)! So how do we account for this??

So, please discuss....

Cheers
G!

 

I just try stick to the rule of 1 inch of fish to one gallon (you can do the calc to metric if you want!)

This is a website I came across when checking out this subject... found it fairly interesting - http://www.aquariumpros.com/articles/stockguide.shtml

Interested to see what others say?

 

I don't personally use a formula as there are so many variables such as how good your filtration is, how often you do water changes etc etc. Common sense prevails usually

 

Hey Vee!

Whilst I agree in part with the Common sense thing, I still think its good to have a basic guideline?

Obviously if you have a sump and do 50% water changes everyday, then you can theoretically keep more fish, whereas if there is no filter at all and you do water changes once a year, then maybe one guppy may be kept, but there must be a common starting point??

Cheers
BigG !

 

Very true Big G.....check out this site, it is rather helpful for those who are unsure of how many fish are enough for their tank size...

http://www.aqadvisor.com/AqAdvisor.php

 

Hmm! Thanks Vee! That was interesting!

It doesn't like Canister Filter Manufacturers tho! Sets their filtration efficiency much lower than the Manufacturers do! Figures I guess!

@Kiazer ... I'm about to go look at your site now! But your formulae is very similar to what I have been told too!

Anyone else with any ideas??

Cheers
Big G!

 

Here's an interesting question.
I have a jebo 20 litre aquarium, currently stocked with 3 baby corydoras trilineus and an apple snail.
I have 2 filters running (sponge and hang on back.
I do a 3 litre water change evry second day and vacume up all uneaten food.
the tank has loads of hornwort in.
I know that the fish 'should' outgrow this tank, but considering the almost 50% water changes and filtration setup, the fish should be ok?
I don't have space for a bigger tank...

 

i use:

tank surface area divided by 30 = cm of fish

for eg. you have a tank which is 61cm L x 32xm W x 32cm H.
you then take the L and W to get the surface area - 61 x 32 = 1952
then you divide that by 30 = 65.07

this then means that you can have 65cm of fish in your tank. However, I apply this only to tetras, danios, rasboras and similar species. when you look at larger body fish such as livebearers or cichlids the result should be halfed...

NOTE - filtration and all other aquarium conditions should be optimal for the size of tank being used.

try to get some of the notes from the breeding programmes in Grahamstown which use Kg of fish per litre of water.... only problem with that is that I dont weigh my fish ...

 

10i, your corydora's may be ok in your 20L, as they stay quite small... but if you know if big apple snails get.. That's gonna be a big fella. Beautiful creatures.

 

The problem with the 1 inch per gallon is you can either fit 5000 guppies or 1 Arowana into a tank. The needs on tank size and Filtration are imensely different.

If memory serves me correctly, its also based on a 40 year old infomation based on the then current filtration systems available.

Nice to use then, absaloutely useless today, unless you going retro with an undergravel filter.

Further to that, some websites argue that because of the more effecient systems available today, you can put upto 1 1/2 times the amount of fish (in Length) into your tanks.

I'v tried it:
I have about 80 Tetras and rasboras in 80l. Ran a Fluval 305 on it , and did waterchanges every 2 weeks. Filters where still clean
The down side is Fish dont like being cramped and they stress. When I halved that the whole tank settled, and the fishies where a whole lot happier


On the Flip side, based on the 1 in rule, had less than 10 Juvenile Balas, Tinfoils and Dollars in a 1.2m. The FLuval 305 on there was changed weekly, and it was like Snot and mud in the filter.


As Dolphin says, it works for some species and not others.

Personally common sense, good effective filtration and some decent homework is the real answer.


Dolphin, do they use a Fish Scale?

 

lol...

I suppose there's a matrix of estimated fish mass by species and size...I'll try to find their research notes that I have somewhere on fish breeding.

 

Hi there,

I am the one who created AqAdvisor site. Its different from other sites/formula because I have used fish weight instead of length and also each species has its own "bioload factor" to further compensate for more active vs less active species. Not all fish inches are equal and as most of you know, an inch from a larger species is different from a smaller species. All of these are taken into account.

It also handles other things (actually much more challenging) such as potential compatibility issues between species, which is still being worked on. If you specify your filter, then it will also figure out if you have enough filtration for your total bioload.

The reason Canister numbers look low is because I took 65% of all filter capacities, not just for canisters. IMO, all manufacturers are too idealistic/optimistic with their quotes and I believe many experienced keepers do too...

I am looking for more feedback on this app though. I've received more than 1000 feedback and they are already addressed. But more the better! :bigsmile:

 

1 inch per gallon is too general, and only works for specific fishes.

I believe that article is a good starting point. Most of it is built into AqAdvisor already.

Try AqAdvisr site. It will tell you how much stocking level you have (once they are fully grown up), if your filters are enough, and how much water changes you are supposed to do.

I've also introduced a new feature today, which allows you to specify size of each species, but this is still experimental.

This is kind of where I started with AqAdvisor. But as you mentioned, it only works for small species hence I ended up assigning a different number for every species in the app. Many people have commented that it works surprisingly well. I spent over a year worth of my own free time into it, and I went live on Sep 2009.

I still do weekly releases (usually on Sundays) with a lot of updates as you can see here:

http://aqadvisor.com/forum/viewforum.php?f=3

I just did a release few hours ago with the following release note:

What's new for 2010 01 24 build:

- Added Dario Dario as an alias to Scarlet Badis.
- Added Flyspeck Hardyhead (Craterocephalus stercusmuscarum).
- Added Bahia Red (Geophagus sp. Bahia Red).
- Added Tiger Muskie (Esox masquinongy x lucius).
- Added Sabretooth Tetra/Payara (Hydrolycus scomberoides).
- Added Red Tail Barracuda (Acestrorhynchus falcatus).
- Added Long-Tailed River/Antennae Stingray (Plesiotrygon iwamae).
- Added Apistogramma atahualpa.
- Added Apistogramma baenschi.
- Added Apistogramma bitaeniata.
- Added Apistogramma sp. Black-Chin.
- Added Apistogramma borellii.
- Added Apistogramma sp. Broad-banded.
- Added Apistogramma elizabethae.
- Added Apistogramma cf. eunotus Orange-tail.
- Added Apistogramma hongsloi.
- Added Apistogramma sp. Mamor.
- Added Apistogramma sp. Maulbr.
- Added Apistogramma panduro.
- Added Apistogramma sp. Parrot.
- Added Apistogramma cf. resticulosa Mamor.
- Added Apistogramma rupununi.
- Added Apistogramma trifasciata.
- Added Apistogramma uaupesi.
- Added Apistogramma viejita.
- Updated the size of Leopard Bushfish to 6 inches.
- Size of Neon Tetra has been reduced slightly to 1.5 inches.
- Mouth size of Angels and Altum angels have been reduced to 1.5 inches.
- Size of Harlequin Rasbora has been bumped up slgihtly to 1.6 inches.
- Ceylon Puffer has been marked as brackish.
- Updated minimum tank size for African Butterfly Fish to 24x12.
- Updated size of Denisonii to 5.5 inches. Minimum tank size has been set to 36x12.
- Minimum tank height requirement for Spotted Climbing Perch has been significantly reduced.
- Bioload for Angelfish has been increased slightly.
- Bioload for Altum Angel has been increased slightly.
- Minimum tank sizes for large species have been updated.
- Size of Geophagus brasiliensis has been increased to 11 inches.
- Size of Apistogramma agassizii has been increased to 3.5 inches. Also max pH has been reduced to 7.
- Size of Cockatoo Apisto has been increased to 3.5 inches.
- Size of Macmaster Dwarf Cichlid has been increased to 3.5 inches.
- Size of Panda Dwarf Cichlid has been increased to 3.5 inches.
- Size of Steindachner Dwarf Cichlid has been increased to 4 inches.
- Added Lustar Hydro Sponge H0 filter (on the last build to be more accurate).
- Hagen AquaClear filters have been also listed as just "AquaClear filters". Many people didn't realize that they were under "Hagen" brand name.
- Added Marineland Duetto series filters.
- Added Eheim 2080/2180 Professional 3 series filters.
- Added some more large tanks.
- Bug fixed: Sometimes, the app was mis-reporting a warning related to similar shoaling species. This has been fixed.
- New feature: Now juvenile sized species are supported! This feature was a huge pain in the <insert your favorite part here> to implement - there might still be some bugs related to this and overall bioload calculation on these sub-adult sizes, hence may require further fine tuning. Please let me know if it looks right. A bonus - once you enter your species in juvenile sizes, you can flip back and forth between juvenile mode and adult mode. When you flip, the application will automatically re-calculate stocking %, filtration capacity %, and water change % so that you know what you are dealing with once they are grown up. I did not change the warnings so those will continue to assume all species are grown up. Try it out!
- New feature: Now the app allows users to flip between two window sizes. One is ideal for laptop users and the other is ideal for those who use monitors with higher resolutions.
- Total number of tanks in DB has been increased to 66.
- Total number of filters in DB has been increased to 245.
- Total number of species in DB has been increased to 698.

Try it out, I think you will be surprised.

Yes, and bioloads of fishes are more directly related to the weight, not length. With this in mind, you can see why 10 inch fish will command much more than 10 times the bioload of 1 inch fish.

Not quite true. Unless your current filtration is just about at the limit of your current stock, adding more filtration doesn't really allow you to add more fishes. You will need to do more water changes, however. Having said that, I always suggest keepers to overfilter their tanks - it never hurts.

I believe AqAdvisor will handle these cases correctly.

I am trying to build an app that will allow me to capture as much information from experts as possible. AqAdvisor started off by using many general rules, buy designed it so that I can also implement as many exceptions as I want. If you can describe incompatibility between two species, I can probably get AqAdvisor to display them when those two are selected together.

This is not very hard to do, and AqAdvisor does that internally when it calculates bioloads.

If anyone finds that AqAdvisor doesn't correctly display the results, please let me know! If it is indeed wrong, I'd like to fix it! This includes both bioload aspect and compatibility aspects.

Thanks!

 

Hey Yhbae!

Thanks for the info! Interesting stuff! I wouldn't even know where to begin with a project like that?? I guess thats why the initial program took 1 year to get running??

I have a suggestion?? Could you add Sponge Filters to the list of filtration?? I know its a minimal affect, but still has some affect?

I'm glad to hear that the Shoaling glitch has been sorted! It was telling me that Horseface loaches and Neons shoal together! haha!

Oh, and if you are going to stay around this forum apart from this thread, maybe pop a hello into the new members thread??

Cheers
Big G!

 

Not quite 1 year but it took me from Jan 2009 until Aug 2009 for the initial version which only had about 120 species and may be 20 filters. I probably had about 20 attributes by then. Right now, I have around 50 attributes per each species to figure out the compatibility mess amongst other things...

I believe I have two brands that are listed already - one of them is Lustar and the other I don't recall the name. Do you have any specific brands in mind?

Yeah. This app, like any other app, became more and more complicated and started to show some bugs... I hope that bug doesn't show up again!

For those who don't know what this is about: AqAdvisor allows me to group species that are different but will shoal together. In this case, it was being mis-reported. And I'm sure there are other species that do shoal together but I've missed them. If anyone finds them, please let me know!

Will do. Thanks!

 

hello yhbae and welcome to TASA!

I'm having a look at your site now...very very interesting and usefull info there that I will comment on in detail soon as try all sorts of different combinations

 

Much appreciated! Apps like this that relies on knowledge database is not that useful without knowledge populated into it! More feedback I get, the better app will become!

 

yhbae I take my hat off to you for spending all that time developing, in my opinion, a very good app and one which is much needed for the hobbyist I think it's great and will also play around a little more on it to check out different combination's etc.

 

Looking forward to hear some feedback... Thanks. :blink1:

 

As far as I know the 1 inch per gallon rule is old an applies to inefficient under gravel filters.

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