what is over stocked to an established aquarium?

FDshoes

New member
Let me begin by stating that I have been in the hobby for about 6 yrs now. First 3 years was with a 90g FOWLR that I purchased off someone on craigslist. 3 years ago I upgraded to 180g reef.

That being said I always read about stocking limitations or min tank sizes for certain fish and it seems to always be geared towards the beginner within this hobby. Add slowly, no tangs in a 4ft tank, any fish that isn't "durable" wait many months before trying them, etc.

What about for the well established tank that is running with few or zero issues? what is the max capacity of that tank? Personally I feel it all depends on the fish in that environment. mAX Size, activity level, diet, day vs night active, amt of live rock, filtration, amt/type of coral you want to keep, and of course temperament.

What are peoples opinions on healthy stocking levels for well established tanks?
 
my tank I have a fairly heavy stockload IMO. Knowing this I stick to LPS and softies because I feed to much and have to much waist for LPS. And everything seems to thrive thus far 3 yrs in:

1 dejardini sailfin tang
1 blue hippo tang
1 yellow tang
1 purple tang
1 maroon clown
1 pink skunk clown
1 chalk basslette
3 wrasses (carpenters, 2 red fairy)
4 bangai cardinals
3 bipar anthias
2 zebra dartfish
7 various shrimps
various softies and LPS

Do not plan on adding any more large fish but do plan on adding 2-3 more anthias and possibly another wrasse or two.

by reading threads on this site most would say this is over stocked yet I do not feel I am overcrowded whatso ever nor do I have much territorial aggression. besides the 3 anthias everything listed has been in this tank for well over a yr and most have been with me for 3+ since the 90g days.

IMO there is no correct answer to this stocking question only your own expierence within this hobby and your current tank set up can answer that question.

As long as everyone has stress free swimming zones and you have adequate filtration to handle the mess load there is no set limit on capacity.
 
If you can extract the biomass for the amount of fish in think you are fine. Do a few more water changes to keep up with good maintenance
 
Exactly established tank plenty of live rock good filtration. As long as everyone within the environment has enough room and the aggression level stays low feel free to add more. Of course this not for any tank less then a year old but once its established and you know the needs of your creatures feel free to add more.
 
I would be very interested in seeing a few pics of you tank..maybe a video

also I would assume you have a pretty good CUC going on also. or do you not?
 
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Yes I do have a fairly large cuc don't know exact numbers but various snails and hermits along with the 3+ peppermint shrimp, 2 red cleaners, 1 scarlet cleaner, 1 coral banded shrimp, 1 horliquin shrimp. I also run a 20 gal refugium with calupera live rock and a decent sand bed.
 
What are peoples opinions on healthy stocking levels for well established tanks?

i have 15 fish in a 75g. it really depends on the different species and making sure everything is compatible regarding feeding habits and territories and such. everything seems to be thriving as much as i can tell.
 
Add slowly, no tangs in a 4ft tank, any fish that isn't "durable" wait many months before trying them, etc.

Well, these are 'rules' that ought to be followed, regardless. But stocking, or overstocking, a tank is a function of an almost infinite set of criteria. Rules-of-thumb are simply that. I do think a few things are generally true though:

  1. Higher bio-load puts more pressure on the system and things can spiral out of control more easily and more quickly.
  2. Nutrient export is even more critical, and may require 'over-sized' or 'redundant' approaches
  3. Overstocking can result in more disease or competition problems
Having said all that, I have a very heavily stocked tank; 41 fish in a system of about 325 'swimmable' gallons. Five tangs, eight anthias, 7 wrasses, four butterflyfish, three cardinals, four chalk basslets, two clowns, two dwarf angels, and a bunch of singles.
 
Overstocked or not depends on your perspective. The biomass issue can be solved with enough water changes, so technically if you are diligent you can always avoid biomass issues. Swimming room, compatibility, territoriality, on the other hand, depend more on the physical size of your tank. Whether a fish is out-competed for its food is a function of tank space and your stocking list. There isn't a hard and fast rule (e.g., you can't say 1 inch of fish per X gallons). It really depends on the particular fish and stocking list.

If your fish are living and growing, that's one indicator that you are not overstocked. If they are fighting, get sick frequently, or are dieing well before their expected natural lifespan, then you're probably overstocked.

Your list above seems pretty heavily stocked for a 180, but if everyone is happy then it's working for you.
 
All our bio filters, live rock, vary in size and capabilities. We all have a different amounts of surface area and we also all have varying levels of low oxygenated areas for nitrate consumption bacteria so its hard to say what is overstocked for one person may not be for another person.

Overstocked, I feel is when you exceed your biofilter's capabilities at its MAXED potential and you have to rely heavily on super skimmers, nutrient export methods and etc. to really control your levels.

A under stock tank can usually suffice with just a few water changes without the assistance of super skimmers, reactors and other nutrient export methods because the bio filter can handle all the waste production caused directly or indirectly by your livestock.

Wastes > Bio filter = Overstocked
Wastes = Bio filter = Tipping point
Wastes < Bio filter = Understocked

That is what I would consider Overstocked.
 
Overstocked, I feel is when you exceed your biofilter's capabilities at its MAXED potential

Trouble is, there is no way I know of to reliably predict (or measure) this. Rules-of-thumb have cropped up over time, but I think we'd all dismiss them as not particularly helpful. My own experience is that the biofilter adjusts to match the bioload and I have very little sense of what the maximum point might be, for example, in my current tank. All I know is that it is some point beyond my current bioload. Plus, the biofilter isn't terribly good at managing to low N and P levels.

I like your approach, however, I would apply it more to nutrient export than biofilter. So, if your nutrient export exceeds or matches input, you are good to go. If not: overstocked! The other consideration is 'social' - is there enough space for the fish population to exist in a semi-normal state. You may exceed the 'social' constraints before you exceed the nutrient export capacity of a system.
 
i have 15 fish in a 75g. it really depends on the different species and making sure everything is compatible regarding feeding habits and territories and such. everything seems to be thriving as much as i can tell.

Do you run a skimmer? Just curious as i have a 75.



Back to the subject imo overstocked should be an eye test you can just tell when a tank is full
 
THe general "rules of Thumb" are there for newbies to give them an idea of were to start from. Once you have been in the hobby for a while you know which rules can be bent and which ones can be thrown out the window. The two main things I look at for stocking limits on a system, is making sure you are able to remove more nutrients than the fish and feeding are producing and inhabitants interaction. If all you have is 3 tangs in a 220g tank but they are constantly fighting, then you over stocked that tank.
 
i have 14 fish in a 60g cube (and 4 shrimp)
ready?
4 orangestriped cardinals, 2 dartfish, 2 clowns, 1 firefish, 1 blue eye cardinal, 1 rainsfords goby, 1 tailspot blenny, 1 ruby red dragonette, 1 tanakas wrasse. the 4 shrimp are a cleaner and 3 sexy.
biomass wise, they probably weigh about 6 ounces. not very big, but lots of movement and character.
no aggression, either.
i would still like to add 2 greenstriped gobies. then i could say i have 16 fish in a 60g, and watch peoples heads spin!
 
The number of fish you can safely stock depends on,

The quality of your husbandry.
The size of your fish.
The niches your fish use. A Benny is unlikely to have conflicts with a chromic. If fish use different parts of the tank and substrate, they are not likely to compete.
The swimming habits of the fish. Tangs are well known to need room to swim in.
The aggressiveness of the fish. There are some damsels that would probably murder everything in the tank.

There was a time when very small and cute Goliath groupers were sometimes sold in the trade. While scuba diving, I have seen Goliath groupers that looked about the size and shape of a Mini Cooper. Imagine that in a reef tank!
 
i have 14 fish in a 60g cube (and 4 shrimp)
ready?
4 orangestriped cardinals, 2 dartfish, 2 clowns, 1 firefish, 1 blue eye cardinal, 1 rainsfords goby, 1 tailspot blenny, 1 ruby red dragonette, 1 tanakas wrasse. the 4 shrimp are a cleaner and 3 sexy.
biomass wise, they probably weigh about 6 ounces. not very big, but lots of movement and character.
no aggression, either.
i would still like to add 2 greenstriped gobies. then i could say i have 16 fish in a 60g, and watch peoples heads spin!

This is why number of fish isn't a good indicator.. 14 fish in a 60 cube sounds like.too many.. but the fish selected make it great.. they are all small fish and fill different role/use different space.. if you had 14 fish and several were tangs angels large wrasse etc.. it would work..

I had 14 fish in my 75.. but 5 were cardinals and 2 were nano fish...
 
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