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Hi;

Keeping this rule in mind, one inch of adult fish per one gallon.

Does the above rule also apply to snails and shrimp?

I feel our community tank is pretty near stocked.

We're actually maintaining about 50-55 adult inches of fish for a 65 gallon tank. I don't want to push the limits.

Am I able to add a few shrimp/snails?

THX

Just based on what I've learned here, I've found that the 1 inch of fish = 1 gallon can flex a lot too, depending on what kind of fish you have (heavy bodied or slim, big waste producers or not, etc). Sometimes, the rule is often quite variable, but it does have it's limits. What kind of fish do you have in your 65 gallon tank?

As for snails, I have no idea, unfortunantly. But that is a great question. I'm rather curious as to what the other forum members here have to say on that one.

No, it's not a stupid question by any means. For one thing, if you're suspicious of an easy rule of thumb like this, then it shows you're putting your thinking cap on, which is always a good idea in the world of fishkeeping.

The "1 inch per gallon" rule is at best an approximation. At worst it can be positively misleading.

For example, take a 55 gallon aquarium. According to the 1 inch per gallon rule, you could have 40 Neon Tetras in there, or 3 adult Oscars. Ha ha ha ha ha. Put 3 Oscars in a 55 and they're seriously cramped - just ONE Oscar on its own needs a 90 minimum, and a 125 is better. On the other hand, the 40 Neons have space to spare, which means you could bring the size of that shoal up to 60 without impacting the biological filter unduly, provided that the fishes were introduced in stages.

Even before we consider such matters as the behaviour of the fish, two factors complicate the situation considerably right from the very start. Biomass and metabolic rate. A fish with a large biomass is going to produce more waste than a fish with a small biomass. Biomass is fairly closely related to the volume that the fish occupies in the water, but this again is complicated by other factors - such as the presence or absence of large bony armour such as that developed by Doradid catfishes (which increases the density of the fish, i.e., the mass per unit volume, and therefore means you have a heavy fish). This is offset to an extent by the fact that the bone is metabolically relatively inactive compared to organs such as the brain and the heart, but there's still some metabolic activity being conducted within the bone (including immune system related activity) so here again we have yet another variable that is going to affect the easy rule of thumb in a manner that is not immediately obvious.

Once biomass has been dealt with, metabolic activity is the next factor that is going to affect the equation. Fast swimming and active fishes such as Zebra Danios will need more space than, say, a relatively sedentary Otocinclus catfish, despite their being the same approximate size. Likewise, a fish that spends much of its time chasing small planktonic organisms at speed in open water is going to have a higher metabolic rate than an ambush predator that spends most of its time sitting on the bottom pretending to be a rock while some unsuspecting small fish swims past and becomes lunch.

Once those two controlling factors have been dealt with, the next issue is fish behaviour. Apart from their small size, Neon Tetras will be able to live in the 55 gallon in numbers because they are shoaling fishes. They group together naturally in the wild for protection against predation, and will likewise appreciate being kept in a large shoal in an aquarium. Oscars, on the other hand, are strongly territorial fishes that demand a large amount of aquarium 'real estate' for the conduct of their life business, epsecially during breeding, and if they feel that they are overcrowded, they will deal with that overcrowding issue simply and ruthlessly - the strong individuals will exterminate the weak ones. Brutal but effective.

Another factor that will crop up if you keep certain Loricariid catfishes is diet. Certain Loricariids require wood in their diet - yes, they eat wood - and because wood is a fairly low-nutition food, they have to eat a lot of it. Of course, wood isn't the only foodstuff they eat, but the fishes in question have evolved to need wood in the diet to aid digestion of other matter consumed such as filamentous algae. Trouble is, they eat a lot of this, and, as a direct consequence, produce a lot of ... waste. Which in the case of these fishes is in the form of huge strings of woody faeces that are going to require more biological filter capacity than the similar faecal output of a shoal of Neon Tetras.

If you're beginning to think this all sounds complicated, then at first sight it is ... but ultimately, common sense should make its presence felt at this point. You ask yourself certain key questions, and the answers to those determine the minimum aquarium size for the fish in question. The key questions being:

[1] Does this fish grow to be small or large?

[2] Is the fish relatively sedentary, or is it highly active?

[3] Does it have a large appetite, or is it a relatively modest feeder?

[4] Is the fish highly sociable, or is it strongly territorial and aggressive?

[5] Does the fish have any special features (unusual diet etc) that add to the space requirements?

On this basis, Tiger Barbs are going to require somewhat more space than similarly sized Tetras, because they have bigger appetites (Barbs are well known in the fishkeeping world, particularly large Barbs, for being garbage compactors with fins at feeding time), and will also need somewhat more space to offset the tendency of these fishes to be nippy toward slow moving and long-finned fishes (a combination that should be avoided in any case). Bala Sharks, being large, very active AND shoaling fishes, will place HUGE demands upon space (250 gallons should be the size of tank that is a long term home for these fishes, and that's a baseline setup) because you'll need to keep several of them in a group and they'll need LOTS of swimming space. On the other hand, the Prehistoric Monster Fish, Thalassophryne amazonica, will make do with 40 gallons because it spends most of its time sitting still pretending to be a rock.

Hopefully this will give you an insight into why easy rules of thumb should be treated with due caution.


Panda Catfish fan and keeper/breeder since Christmas 2002

The 1" per gallon rule has lots of faults and you should never use it as your only means of deciding stocking. Probably not even as your main way of determining how stocked your tank is but when stocking snails they do mostly follow that rule. 1" of shell diameter per gallon is usually an acceptable stocking. Shrimp fall way under that rule. Many suggest 1 shrimp per 1/4 or 1/2gallon. I know a few people who breed shrimp will often end up with around 40-50 in a 10g with no problems. Shrimp produce very little waste and you can add a dozen or so to most any 55g setup without noticeably impacting water quality unless your already way overstocked. The main thing to keep in mind though is that lots of fish eat shrimp. All gouramis and cichlids are a potential danger to shrimp and usually to applesnails as well.

Hello;

Thx all for your replies.
Calilasseia, I appreciate the time your answer/typing must have taken!

Our tank consists of some danio's, cory's, an angelfish, one red tailed black shark, a few tetra's and a burmese(young one) loach.

Having read your answers, we'll probably try to get some cherry shrimp down the road.

I've read somewhere that loaches like to eat shrimp, I'm thinking that would apply to a mature loach eating baby shrimp?

yes/no?

Should we stay away from shrimp?

Thanks again

Just took a look at the stocking. Some possible issues arise from your stocking list. The principal one being the Red Tailed Black Shark. Now in a 65 gallon setup, it should have enough space, but watch that fish like a hawk, because Red Tailed Black Sharks become increasingly territorial with age and have a habit of bullying other bottom dwellers. You can mitigate this somewhat by providing lots of caves (more than one cave per bottom feeder) but even so, there are some ornery specimens that take a sadistic delight in chasing other bottom feeders out of their caves. It can become something of a blood sport with some Red Tailed Black Sharks, but thankfully, not all, particularly if they have space. If your Red Tailed Black Shark has one cave he can call home, and sticks to chasing other fishes from that, you should be reasonably OK.

The Corys are the fishes that are likely to appreciate hiding places that are large enough for them, but too small for the Red Tailed Black Shark. Your Burmese Loach will also appreciate such provision.

Remember, a Red Tailed Black Shark, when fully grown, is a 7 inch fish, and a chunky, muscular one at that. It's not afraid to mix it with some fairly rough company. In your 65, it'll probably grow pretty well, and you'll have a sizeable and pretty feisty fish cruising around in there.

Having dealt with that, your next problem as far as shrimp goes, is that quite a few of your occupants will happily dine on shrimp. Your Angelfish CERTAINLY will, because in the wild, Angelfish eat shrimps such as Macrobrachium species, and an adult Angelfish can dismantle an adult shrimp with frightening ease once it develops a taste for them. There are some shrimps whose adults grow too big for your Angelfish to consider a snack - Macrobrachium rosenbergii is a prime example - but many of these (the rosenbergii included) grow big enough to treat some of your fishes as food in turn! A big adult Macrobrachium rosenbergii reaches a size where it becomes an item on a human dinner plate!

Even your supposedly "inoffensive" Corys will, once they discover baby shrimp hanging about, decide that a little live snack is the order of the day. As a positive side effect, this will condition your Corys so that they are likely to spawn, but be advised that while the Corys will leave an adult shrimp, even the smaller species, relatively unmolested, all bets are off vis-a-vis baby shrimp. Even if you find a shrimp species whose adults can survive the rough and tumble of your aquarium, with the Angelfish huting them down and probably the Red Tailed Black Shark too once it piles on some body mass, the survival chances of the baby shrimp are practically zero. EVERYTHING in your tank, even the Tetras, will be snacking on those the first chance they get. Which means that if you fancy the idea of breeding your shrimp, a separate shrimp aquarium will be necessary.

The good news of course is, that as stated above, shrimp tend to produce very little extra bioloading on your filter. Plus, if you find a species whose adults are capable of surviving the attentions of your Angelfish without growing big enough to eat your Danios and Tetras (and in the case of Macrobrachium rosenbergii, your Corys and loach too!) the babies will provide a live food supplement that will keep your fishes nice and healthy. However, before you splash out on a batch of those drop dead gorgeous Red Cherry Shrimps that are sky high desirable (and expensive as a result), bear in mind that your Angelfish will treat any Red Cherry Shrimps in there as a gourmet banquet to savour at will, especially once the Angelfish grows to be a sizeable adult. Remember that an adult Angelfish can be a surprisingly large aquarium occupant - I had a male as part of a breeding pair as a teenager that was nine inches tall.

Oh, and I wouldn't worry too much about my long posts - I'm infamous for it here. You think my efforts in this thread are long, you want to see some of my past musings ...

EDIT: Almost forgot. Go to this site as your one stop shop for many things shrimp and freshwater crab related.


Panda Catfish fan and keeper/breeder since Christmas 2002

Baby shrimp won't survive in just about any tank with fish. Any type of fish will eat them. Adults of most shrimp species are fine with loaches except maybe large clown loaches with some of the smaller shrimp. The angelfish is the biggest problem. Not just for shrimp but mine was death to my applesnails. The snails couldn't come out of their shells for more than a few seconds before the angel was on them. Loaches are also avid snail killers. My yoyos were of a similar size and temperament to the burmese and I had to move them to a different tank because they kept killing the applesnails I was breeding. There were around 30 empty shells laying around the tank. I'd purposely throw hitchhiker pests or any other snails I didn't want into the loach tank. I'd avoid snails unless you want to setup a tank with no loaches or cichlids for them but you might be able to keep larger shrimp. I'd test it with some ghost shrimp since they only cost about $.25 each around here. Amanos are slightly bigger than ghost shrimp but not as inexpensive should the angel decide to make them a snack. Another option if you really want shrimp would be filter feeding shrimp commonly known as bamboo, flower, fan, or wood shrimp. These are very large shrimp but they only eat tiny particles out of the water. They do need a place to hide and a place to perch on(wood preferred, rock or plant acceptable) in front of the filter so they can fan the current for food. I don't think even angels would bother these large shrimp and despite their size the shrimp are incapable of eating even baby fish. A bit harder to find and more expensive than the smaller shrimp species though.

Your loach will also eat snails. Some snails quite large.