What saltwater fish can I safely keep in a 10 gallon tank?

The rule of thumb is 1.5" of fish per gallon of tank. So estimate the length of each fish you have, add them all and divide by 1.5. This will give you the size tank you will need in gallons. In a 30 gallon tank you can keep 45 inches of fish (i,e, 45 fish, each 1 " long or 30 fish , each 1.5" long, etc. Do not forget to leave some space for growth of fish.

It is very difficult to get a good biotope in a just 1 foot long tank unless it is a few feet high. You will not be able to keep fish in it, only invertebrates, maybe a few shrimp or sea anemones. It is much harder to keep the water healthy in a small tank,and the appliances needed for running a salt water aquarium cost pretty much the same (if available) as appliances for a larger tank. I suggest you join a club of salt water aquarists who will be able to start you off perfectly. Your local fish/pet shop should be able to point you to a club.

Guppies or Neons are excellent "starter" fish. Care is simple and they are inexpensive. A standard 10 gallon tank is recommended to start. Most people don' t realize the amount of "work" needed to maintain a tank. Filter maintenance, monitoring water chemistry, water changes, monitoring fish health and providing a balanced diet are just a few items that need regular attention to keep a tank thriving. Even though fish aren't as cuddly as cats and dogs, they do have their own personalities and even respond to their owners, especially at feeding time! Studies have shown that simply watching fish in a tank can lead to a reduction in both heart rate and blood pressure. It is quite relaxing.

Hi there! The general rule of thumb is 1 gallon for each inch of fish, so I think that you may need a bigger tank. If the bettas are 2 inches each, they each require 2 gallons of water, making the minimum tank size 14 gallons. Since male bettas can be territorial and aggressive, I highly recommend a larger than normal tank with lots of hiding places for 7 fish (at least 20-25 gallons). You should also watch them very carefully for fighting, and have a backup plan in case any of them need to be separated. Good luck!

The small size will limit the species of fish as well as the number. White Cloud Minnows or Guppies would do fine in a small tank. You could keep no more than 2 or 3 fish total. If you are looking for company for your Betta, the same species can be kept. Other options include Otocinclus (Otos), Corys, Platys or Harlequin Rasboras. Again, no more than one or two in addition to the Betta. Water changes for any tank are simple. Change no more than 30% total volume at a time. Use a water conditioner to remove harmful chemicals and make sure the water is temperature matched to prevent stress or shock. Rinse the filter in tank water, not tap water, to preserve beneficial bacteria. Vacuum the substrate every couple of weeks.

Yes it is possible, however, unless you have a lot of experience keeping saltwater fish, please do not even attempt it. Most wild caught saltwater fish will not feed when they are in an aquarium, and only a small percentage will ever learn to feed. Please leave them where they are happy and healthy and where they belong, the sea.

The goldfish can get very big and may require a significantly larger tank as they grow and grow. As a rule of thumb, you need 1 gallon of water per inch of body length of fish. So if you have three 1 inch fish, you will need 3 gallons of water. I suspect you are at your max already in the smaller tank. Just so you know, most people do not have goldfish in tanks with tropical fish. You may consider getting two tanks One for your cold water fish like the goldfish, and one for your tropical fish that require a warm water temperature. For the goldfish I would suggest a minimum of a 20 gallon tank. For the Danio, I suggest to get a few more of these as they are schooling fish and a 10 gallon would be just fine. I hope this is helpful and please feel free to post any additional questions.