37 gl tank, how many fish I can put in!!!! 9 fishes now but the tank looks empty!!!

[flipperfeet]

Dear all,

I am new to the hobby and very excited! I bought a 37 gl aquarium along with 3 silver dollars, 5 cory catfish and 1 flame dwarf gourami. I have been reading and testing my water for almost 3 weeks! Very interesting chemistry, I am still though waiting for my tank to fully cycle as I still have some ammonia.

My questions is: once my cycle finishes, I would like to add more activity to the tank. I am thinking to add 5 guppies and 3 snails to the group. Do you think this is too much for the tank size? The fish I have now are not very active

I am not a moderator as some are in this thread, but I managed an LFS for about 6 years and have kept fish for 50.

A word about pH & KH: There is an ideal found in a fish's native habitat and this is important for wild-caught fish, but for many fish sold in the trade, they have never experienced their "native pH & KH". Additionally, VERY few fish dealers and LFS are optimizing tank pH & KH to native levels for each of the species they are selling. It is more likely every tank in the store has the same pH & KH and it is close to your tap water. The fish you are buying at an LFS are generally acclimated to local conditions. A fish may do better and breed more freely if you approximate the native pH & KH, but a community tank is not a breeding tank, and if your pH is in the 6.8 to 7.2 range you are not harming acid-loving or alkaline-loving fish, similarly, the local KH is likely fine.

Your silver dollars will do better in a larger school, but again you are not doing irreparable harm to them in a school of three. They are likely to outcompete your other fish for food so expect them to grow quickly. Not knowing if you got dime-sized or quarter-sized fish it is hard for us to tell you how long before they should be in a larger tank, but if they were tank-raised they were likely in a tank smaller than yours before you got them. A year is a good estimate of the amount of time before you will want to rehome them.

I don't know if anyone actually answered your question about how many fish you could have. This is highly dependent on filtration and aeration. Your list contains 17 small to medium-sized fish, even with a small filter you should be fine. I over filter my tanks and often populate tanks well beyond the old-school rule of thumb of one inch of fish per gallon.

 

[Byron]

There are some important misunderstandings in the above post #61 which need clarification.

Of the four water parameters, GH and then temperature are the critical ones. This does not mean that pH is irrelevant, but there is more room for variation provided the pH is not in a state of fluctuation. However, it would require a very length explanation to deal with the pH issues here, so I will move on to the other two items that I feel are more significant.

Shoaling fish, by which I mean the species that live in groups (schooling is a common term though it implies behaviours not usually seen in freshwater fish), must have a decent sized group in the aquarium. If not, they are being harmed. Scientific studies have determined that aggressive behaviours are increased, the fish is more nervous and darting movements increase, and there is a latency to feed. All caused by too few in the group. This was noted when species were maintained in groups of three, five and ten. There is no doubt but that the fish in the groups of ten were in better condition, and that means fewer health risks long-term.

The other item concerns filtration. The "number of fish" is not determined by filters; aeration does factor in, but larger filters or more filters will not allow more fish and not improve the biological filtration. Stocking any aquarium is a matter of the species, the numbers in each species, the combination (compatibility) of the species which involves more than just behaviours, and the space afforded them.

 

[flipperfeet]

There are some important misunderstandings in the above post #61 which need clarification.

Of the four water parameters, GH and then temperature are the critical ones. This does not mean that pH is irrelevant, but there is more room for variation provided the pH is not in a state of fluctuation. However, it would require a very length explanation to deal with the pH issues here, so I will move on to the other two items that I feel are more significant.

Shoaling fish, by which I mean the species that live in groups (schooling is a common term though it implies behaviours not usually seen in freshwater fish), must have a decent sized group in the aquarium. If not, they are being harmed. Scientific studies have determined that aggressive behaviours are increased, the fish is more nervous and darting movements increase, and there is a latency to feed. All caused by too few in the group. This was noted when species were maintained in groups of three, five and ten. There is no doubt but that the fish in the groups of ten were in better condition, and that means fewer health risks long-term.

The other item concerns filtration. The "number of fish" is not determined by filters; aeration does factor in, but larger filters or more filters will not allow more fish and not improve the biological filtration. Stocking any aquarium is a matter of the species, the numbers in each species, the combination (compatibility) of the species which involves more than just behaviours, and the space afforded them.

I have never read anything as silly as filtration has nothing to do with stocking levels and it is unrelated to biological load and the amount of dissolved oxygen in the tank.

There is a whole category of filter media designed specifically to address biological filtration. Circulation directly affects the surface exchange of CO2 and O2.

 

[Byron]

I have never read anything as silly as filtration has nothing to do with stocking levels and it is unrelated to biological load and the amount of dissolved oxygen in the tank.

There is a whole category of filter medium designed specifically to address biological filtration. Circulation directly effects surface exchange of CO2 and O2.

No disagreement with this. But the point I thought I was making is that the requirements of the species is the first consideration. A simple example, one has a 20g high (standard) tank, and you are thinking of acquiring Tiger Barbs. This is not going to work, regardless of the size or number of filters, because (1) the fish need more swimming space to accommodate the necessary numbers (10-12 is absolute minimum considering the normal level of aggression) and (2) they need the space because of their activity level. Without the necessary number of fish in the group, the fish will be under stress because you are denying them something they consider to be essential to their life because it is part of their genetic makeup. And without sufficient space to be themselves, they will be further stressed. This leads to more problems long-term. The filter cannot solve this problem.

Biological filtration occurs in any aquarium, with or without a filter. The nitrifying bacteria (or arachea) will colonize surfaces in the substrate and elsewhere. They will multiply to the level needed, and no more, whether they do this in a filter along with the substrate or not.

Surface disturbance is another thing, and not part of biological filtration as we tend to think of it, but it is usually governed by the water movement from the filter, though not always. I had a 10g tank with no filter, and no light, just a heater. It sat in front of a west window, and had pygmy cories (11) and Boraras brigittae (12), and was well planted. I ran it for a year as an experiment. This worked with these fish, but it would not work with some other species.

 

[dsch132]

Specify that its not pest snails, otherwise people will think: "I dont what she is thinking but those snails that are everywhere in my tank look pretty ugly"

One of my friends bought some plants online, didn't sufficiently clean them, and introduced bladder snails to her betta tank. Soon enough, the snails basically formed their own nation. She was constantly vacuuming baby snails, but they just kept coming back. Finally, the snails are gone, but her tank is becoming overrun by flame moss.

 

[Rocky998]

One of my friends bought some plants online, didn't sufficiently clean them, and introduced bladder snails to her betta tank. Soon enough, the snails basically formed their own nation. She was constantly vacuuming baby snails, but they just coming back. Finally, the snails are gone, but her tank is becoming overrun by flame moss.

Flame moss? Is that a type of algae or is that actually moss? At least her betta has a side snack

 

[dsch132]

Flame moss? Is that a type of algae or is that actually moss? At least her betta has a side snack

It's moss and is actually very beautiful—fantastic for aquascaping. She actually got it from one of my planted tanks! Unfortunately, she has a small setup with strong lights, and it's spiraling out of control. It doesn't help that her tank is pretty vertical and has this (absolutely gorgeous) driftwood piece that always gets in the way of cleaning.

 

[Rocky998]

It's moss and is actually very beautiful—fantastic for aquascaping. She actually got it from one of my planted tanks! Unfortunately, she has a small setup with strong lights, and it's spiraling out of control. It doesn't help that her tank is pretty vertical and has this (absolutely gorgeous) driftwood piece that always gets in the way of cleaning.

I looked up flame moss and it looks really cool! I'm sure its not so cool when its invading...

 

[itiwhetu]

I am not a moderator as some are in this thread, but I managed an LFS for about 6 years and have kept fish for 50.

A word about pH & KH: There is an ideal found in a fish's native habitat and this is important for wild-caught fish, but for many fish sold in the trade, they have never experienced their "native pH & KH". Additionally, VERY few fish dealers and LFS are optimizing tank pH & KH to native levels for each of the species they are selling. It is more likely every tank in the store has the same pH & KH and it is close to your tap water. The fish you are buying at an LFS are generally acclimated to local conditions. A fish may do better and breed more freely if you approximate the native pH & KH, but a community tank is not a breeding tank, and if your pH is in the 6.8 to 7.2 range you are not harming acid-loving or alkaline-loving fish, similarly, the local KH is likely fine.

Your silver dollars will do better in a larger school, but again you are not doing irreparable harm to them in a school of three. They are likely to outcompete your other fish for food so expect them to grow quickly. Not knowing if you got dime-sized or quarter-sized fish it is hard for us to tell you how long before they should be in a larger tank, but if they were tank-raised they were likely in a tank smaller than yours before you got them. A year is a good estimate of the amount of time before you will want to rehome them.

I don't know if anyone actually answered your question about how many fish you could have. This is highly dependent on filtration and aeration. Your list contains 17 small to medium-sized fish, even with a small filter you should be fine. I over filter my tanks and often populate tanks well beyond the old-school rule of thumb of one inch of fish per gallon.

Do you think pH is important or as some members here think disregard pH, only worry about hardness? Therefore, we have freshwater fish on this site being kept in tanks with a pH over 8

 

[Tacocat]

Do you think pH is important or as some members here think disregard pH, only worry about hardness? Therefore, we have freshwater fish on this site being kept in tanks with a pH over 8

Actually you should worry about both, because hardness can affect pH, but not the other way around. GH or general hardness is, as mentioned above, the concentration of calcium and magnesium. pH is the concentration of hydrogen vs hydroxide ions in a given solution. I do not know whether it's calcium that raises pH, but I do know that calcium-carbonate, CaCO3, also in limestone, can raise pH. Therefore, your GH can directly affect the pH, but not necessarily vice versa. Also, you have to take into account kh, which is buffering capacity. Anyway, you have to take into account all of these factors

 

[flipperfeet]

Do you think pH is important or as some members here think disregard pH, only worry about hardness? Therefore, we have freshwater fish on this site being kept in tanks with a pH over 8

ph, KH, and GH are intertwined. That said, I do think pH is important to a point, and I never ignore it because pH shock is real and I have seen it kill fish. For example, I live in a region that relies on groundwater that is at risk of saltwater intrusion. The pH can swing from 7.8 to 8.8 depending on which well the water company is pumping from. So I always check and try to match what is in the tank which starts at 7.1 in the morning and falls to 6.8 during the day due to CO2 supplementation for plants. If I forget to take the precaution of adjusting the pH prior to changing the water I will know immediately because all the MTS will come out of the gravel and rush toward the surface, and many of the fish will move up the water column toward the surface until everything is in equilibrium again. If the pH is within .5 of the tank I do not observe this with a 20% water change.

The point I would like to make is that the typical community tank of those new to the hobby is often a hodge-podge of fish to which they are attracted without a thought about pH and KH or compatibility of the biotope. The fish at their local LFS have made their way through the supply chain acclimating and surviving a variety of conditions including non-species specific optimal pH, KH, and temp. By the time the fish are netted out of the local fish store tank, they generally have been acclimated to local water conditions. So obsessing about a specific water metric in a non-specific biotope community tank has little benefit or necessity. Avoiding the extremes will generally provide good results and is easily attainable by those new to the hobby. To answer your question specifically, I do not agree that a pH of 8 is immaterial, but there are folks who breed discus repeatedly and successfully in tanks with a pH that high. It is a strong proof point for the hypothesis that acclimation is more important than species origin. I feel this is particularly true when breeding is not the objective.

To my mind, the phenomenon that is the beginner's community tank is very cool and to my experience the more common path into the hobby. They are wonderful learning labs where we answer the most important questions like are you a catfish or a loach person, African or South American Cichlid person? Very few people enter the hobby thinking they love water chemistry and want to create a specific biotope and stock it with fish from a single tributary. Most just saw some cool fish and wanted to keep them and then added more. I would have never created a new hobbyist if told them "First off you should only have fish from the same ecosystem" or, "if you want that fish there it will only do well if you buy ten, but you can't buy ten until your tank is cycled." Creating barriers to entry to this hobby is short-sighted, it is already under attack from animal rights folks, making it seem overly complicated does none of us favors nor is it necessary to have a tank of healthy fish.

Berksou's question was straightforward, "how many fish I can put in my tank?" I wish I had $1 for every time I was asked. But I love the question as it opens the door to creative thinking about unique combinations, what got them started and what fish they like. BTW the correct answer to this question is "until you need another tank." This leads to the next question. How many tanks should I have? Answer: n-1, (where n = the number of tanks when your partner tells you to move out.)

 

[ember04]

How many snails I can put in my tank?

I may be too late but just be carful when choosing snails some of them do prefer hard water with out it you may run in to shell problems