Stocking Scheme

Question
QUESTION: I'm fairly new to keeping fish but have done quite a bit of research. I've got a 75 gallon tank that I want to set up but I'm having a hard time finding info about the compatibility of what I could put in it.

I'm hoping to include the following:
Angelfish (4)
Swordtails (6)
Danios (10)

I understand that Angels might eat Tetras so they're out, and Barbs will probably harass Angels so we don't want them. Can you recommend some other fish to include (and how many of each)? Is there any special way I will need to set up the tank with this assortment of fish? Thanks for any help!
ANSWER:  Hi Melissa,
Sounds like you have done a great job researching how to set up your aquarium. That is really great since so many times people don't and regret not doing so.

Angelfish are really beautiful fish. They are cichlids, though, and they can be a bit territorial at times especially if you get a pair out of the 4 you are getting. I raise angelfish and have a pair in my 75 gallon. They get along with the other fish which are really quite an odd group. With them I have one parrot fish, a gourami, 9 black skirt tetras, 3 lemon tetras, 7 rosy barbs, 1 cherry barb, 7 corys, 1 guppy and 1 bristlenose pleco, and 3 zebra danios. These were a combination from several of my other tanks. They all get along most of the time.  The only real problem I have encountered in this aquarium were the angelfish. I originally had 4 and they got along great for about a year. Then one of the largest males got picked on by all the others. I really don't know why. I had to move him into another tank to allow him to regrow his fins. He and his mate later spawned twice and I now have around 36 almost nickel sized babies. They are gorgeous but they too have a tendency to be a little nippy at each other. I am just making you aware that with fish even though you can read about how compatable different types are you still never really know until you place them together as to how they will act. Each fish has a different personality and they can be unpredictable. The fish that you have chosen should be fine together. Just don't expect total peace all the time. They will have their little disputes.

Other fish you could add could be some bottom feeders. The little corydoras catfish stay small and they like to be in groups. There are different types with different patterns and also albinos. They really prefer a sandy bottom but they can do well in a gravel substrate too. You could get at least 6 if you wanted to. You could even get some of the larger tetras without running the risk of them being eaten. I think the main problem with tetras are the ones the size of neons. So far my rosy barbs have never bothered my angels. It helps to control alot of fish problems when you have a larger group. They will then mainly stay with each other and have their little disputes among themselves instead of picking on other fish. Just be sure with all your fish that you try to get more females that males if you are intending to get a mixed group. This is especially true with swordtails and also with any barbs you might get. If you don't get more females than males, the females will be chased unmercifully by the males. With a larger group of females the chasing will be spread out to more instead of just one. You will also have babies with the swordtails since they are livebearers. The angelfish will probably eat them thinking they are a special treat.
You could also get a bristlnose pleco. They don't get huge as the common plecos do, only around 5-6". They love to eat zuchinni and will sneak out of hiding to eat it at night after the lights are turned off.
I have a three spot gourami which is around 4" long. They seem to do all right with most fish and are really pretty.I
would just get one.

As for tank set up most of these fish would really love alot of plants to help them feel secure. You don't have to have live plants unless you intend to get the correct amount of lighting to be sure for proper plant growth. You can create a very pretty tank with fake plants arranged with various types and different heights. Fish also like to have hiding places such as caves created out of rock or just the different fake types that are in most fish stores. Most stores have some really nice fake driftwood pieces that even have areas the fish can hide in. Real driftwood is nice but you do have to remember that it will discolor your water for a while until the tannins are gone.

Be sure to allow your tank time enough to cycle before adding alot of fish. If you don't allow enough time it will create alot of problems with ammonia being too high for fish survival. I know you have probably already researched the cycling procedure so I won't bore you with that but just be sure to be patient and not add too many fish too fast. Also, be sure to always do regular weekly water changes. Nothing is better for fish than clean water.

Best of luck with your new aquarium adventure!
I hope this has helped in some way,
Karen



---------- FOLLOW-UP ----------

QUESTION: Thanks so much you've been super helpful. I know about cycling and water changes as I do have a 10 gallon tank already set up. I have a question about overstocking now. What will you do with all the fish in your 75 gallon when they reach adult size? With my calculations my scheme of 4 angels, 6 swordtails, 10 zebra danios and 6 corydoras would make my 75 gallon overstocked by about 10 inches when they are all adults. I would love to be able to have more fish in this tank - is there a way I can do it without overcrowding?

Answer
Hi Melissa,
The fish that I have in my 75 gallon are already full grown. Any young fish such as my baby angels are in separate grow out tanks and get daily water changes to help them grow faster. In my 75 gallon I do several water changes a week and have alot of extra filtration-more than most of my other tanks. I don't worry as much if I overfilter a tank and do alot of water changes. Also, when a tank is at least 75 gallons there is more water to help with dilution of fish waste. The fish I have are not really considered the really dirty  type of fish. So far I have found as long as you don't get lazy about tank maintenance and you are working with a larger tank with good filtration you can have a little more fish than usual. My filtration consists of a large hang on the back type filter that has two biowheels, two large filter sponges and two extra containers of ceramic chunks. All of these help to provide a place for the benificial bacteria to live. I also have a sponge filter in the tank that is for a 125 gallon tank capacity.It is always better to overfilter a tank than to underfilter it. It is good when you buy a filter to get one that is rated alot higher than the size in gallons of your tank. Example-my oscar tank has a filter that is for a 100gallon tank and I am using it on a 55 gallon. He is the only fish in that tank and I would never put any in with him due to him being so polluting.
I really think you could have a few extra fish in a tank your size as long as you upgrade your filtration and don't add really high polluting fish. Keep up water changes and don't overfeed and you should be ok.

Best of luck,
Karen