How Do You Guys Figure Whether A Tamk Is Under And Overstocked?

[sic0198]

Ya know when someone gives ya a stock list and ya tell them whether or not they're overstocked, how do you do this? I mean how do you figure it out, is it the one inch of fish per gallon rule or something? Please fill me in.

 

[Tolak]

The one inch thing is a guideline, not a rule. The full guideline is one inch of slim bodied fish that are no larger than 3" as adults, per gallon of tank water. This applies only to peaceful community fish.

Many things have to be considered besides the inches per gallon. Tank size & shape, water parameters, aggression levels, if they are schooling or shoaling fish, plus many other variables come into play. This is something you learn with experience, stocking is just as much art as science.


This is the reason you will often get varying responses for stocking, what works for some people often doesn't work for others.

 

[Tokis-Phoenix]

A lot comes down to the type of fish and the dimensions of the tank and even factors like filtration and planting/decor etc. Once you research fish up more and become more familiar with them and knowledgable of them, getting the right stocking will become a lot easier.
A lot of fish also have a minimum tank size (its why you could have 15 neon tetras in a 15gal tank, but not a 15inch common pleco in the same tank). For example, tiger barbs aren't particularly large fish or anything like that (usually grow just under 3inches) but require at least a 30gallon or 3ft long tank to live in due to their high activity levels and the large numbers they need to be kept in.
The inch per gallon thing is only a guideline for stocking as there are so many more factors to take into consideration when it comes to stocking tanks than just size of the fish and gallons of the tank .

 

[Torrean]

three BASIC methods for deciding stocking levels.

1. Inch of fish per gallon (has been covered allready)

2. surface area. You'll need a calculator to do this one. You can find it in the tff faq's. If anyone has trouble finding it I'll pull up a link. This method deals with oxygen diffusion.

3. NitrAte levels. This is IMHO the best method. Keep adding fish (slowly) each month until your nitrates hit around 40 and stay there. Ofcourse you'll get fluctuations but this method takes into account your feeding habits as well as your plant to fish ratio. It also considers any nitrates in your tap water. You still need to consider the needs of each fish. This is only intended to tell you how many fish your filtration can handle.

edit: stupid of me. I REALLY should have mentioned that I have not tested number 3. I simply understock my tanks.

 

[Squid]

I used to use the inch per gallon rule when i first started out, and i still use it now as a quick sanity check. However, the main rule i use now is the common sense rule. I look at my tank and question if it looks overcrowded. I know that in my tank i cant have a large fish, as it won't have enough room to swim properly. I also look at what areas of the tank are being used (top middle and bottom) and decide if it can take any more. I also look at my tank stats. My nitrite levels are so low at the moment that i tend to get a bit of algae, although i now use ferts for the plants which helped). Low nitrites mean that i could add a few more too if the rest of the things i looked at above also indicated that i could... But for smaller fish, 1 inch per gallon is a good start.

Squid

 

[OohFeeshy]

I just judge it by 'eye'. Imagine what the tank will look like when it's fully stocked- you can tell easily when a tank has too many fish in, it has a 'crowded' feel. Bioload does come into it, but the filter should be able to handle it- most of the time stocking levels involve community fish- they're all very low bioload.

 

[three-fingers]

three BASIC methods for deciding stocking levels.

1. Inch of fish per gallon (has been covered allready)

2. surface area. You'll need a calculator to do this one. You can find it in the tff faq's. If anyone has trouble finding it I'll pull up a link. This method deals with oxygen diffusion.

3. NitrAte levels. This is IMHO the best method. Keep adding fish (slowly) each month until your nitrates hit around 40 and stay there. Ofcourse you'll get fluctuations but this method takes into account your feeding habits as well as your plant to fish ratio. It also considers any nitrates in your tap water. You still need to consider the needs of each fish. This is only intended to tell you how many fish your filtration can handle.

edit: stupid of me. I REALLY should have mentioned that I have not tested number 3. I simply understock my tanks.

I use the nitrate method . Though there are minor compatibility problems with my tank (plec and syno), and i will need a bigger tank soon. Other than that my tanks fine with no problems.

 

[fish-r-fancy]

Well when somebody asks you a stocking question that doesn't mean they're always asking you if all the fish will fit in the tank they could be asking about capatablity. So when somebody gives a stcoking list, first I always check for capatability, then I check all of the numbers in schools if any, then I go into about how a lot of fish have a minimum tank size limit and then I try to picture it like stated above. Also like mentioned above the deminsions of a tank,filtration and decorations in the tank come into play.

 

[Miss Wiggle]

yeah i always try and explain the " per gallon rule, it's definately not infallible but it's a good guideline and helps people get an idea for themselves, i always think you shouldn't just say yes or no, you should try and explain why you've said something so people can understand it and work it out for themselves.

i look at the "'s first to get a rough idea how heavy the tank is, then look at compatibility and point out any issues, then look at things like the levels of the tank top swimmers etc.

then i'll take into account any othe factors like if the person posting has stated what they're filtration or decor is. compare this to the requirements of the fish they've asked about and put them together and point anything out if need be.

then i also think about the tank history, if i can remember other posts from the person in question saying they've had issues or not.

from that then you can normally get a rough idea of what the tanks like and make some suggestions.

 

[geo7x]

i dont go necessarily to the " per gallon rule myself, you kind of get to know whether it looks overcrowded or not.

However, when suggesting something to someone, i always look at shoal numbers, and also how big some of the fish could get. So, for example, if someone had a bala shark in a 2ft tank id suggest that they take it out, then round up their numbers of tetras a bit, and then say "once youve done all that, you could do this," or "once youve done that, you should be just right" etc. I always sort out what they currently have, and then sort out whether they could add anything ONCE they have sorted it out a bit.
If someone asks me I recommend " per gallon anyway, its ok for a basic guide, and then they can make their own opinion.