We’re thinking of creating a fish tank for our son, who loooooooves to watch fish.
We’re shooting for a 10-20 gallon tank.
What sort of fish should we put in it? I’m leaning away from goldfish- to messy. We are definitely getting a tiny blue lobster (Hammers cobalt), because they are too adoreable to resist. No mollys or platys- they are boring fish and for no good reason I hate them.
Do lobsters and loaches mix?
Give us some ideas to put in a tank!
Well the problem with crayfish is they usually end-up eating whatever fish are in the tank (eventually).
I have had a few of them. They also love to ruin (uproot) live plants.
I ended up having a crayfish and a dozen or so neon tetra’s in my tank. Then every month or so I would buy another 6 neons to bring the population back to ~12.
Right now I just replaced my 33 gallon with a 25. Stainz and I love it! The tank is very tall, and I find my fish are schooling at different levels now. Very cool!
We have ~10 neons, 6 Blood Fin Tetra’s, 5 other tetra’s (can’t remember their names), 2 Glass Catfish (very cool) and a pleco.
MtM
Don’t get a lobster if you plan to keep fish with it. It WILL eat anything it can catch and it can catch most fish of a size for that tank. A 10 gallon tank is also way too small for it. It may be tiny now, but it won’t be - they’ll moult a couple times a year when they outgrow their shell (which causes undue freaking when you see an empty shell laying in the tank one morning).
My advice would also be to go for a larger tank than 10-20 gallons. Most people think that smaller is easier, cheaper and more appropriate for a youngster. Not so. The smaller the tank is, the less it takes for problems to develop. When you have a youngster involved you WILL have episodes of overfeeding, which will create big spikes in ammonia (i.e. you wake up one morning to a tank full of dead fish). The larger a tank is the more of a buffer there is for dealing with contamination, such as overfeeding, misreading the directions on medication, etc. I would recommend a 20 - 30 gallon high tank. A 20 high for example, has a much smaller footprint than a conventional 20.
As for what to put in it? At first, just 2 - 3 small hearty fish, such as Lemon Tetras, Glowlight Tetras, Zebras and so forth. The idea is to go to the fish store and pick something you find interesting, but also something strong, healthy and inexpensive. Those first couple fish are going to have to endure an ordeal while the tank is “cycling”. Don’t add any more than 1 small fish for every 5-7 gallons for the first 4-6 weeks (this is a rule of thumb and not a formula). Your tank has to finish the cycle before you stock it up.
What this means is it has to develop a biological filter, which is made up of helpful bacteria. This happens through the “cycle”. First, fish waste and uneaten food biodegrade and produce ammonia in the water. This is toxic to fish. A few days to a week after you add fish to the tank, the ammonia level will spike up, because there is more ammonia than the existing bacteria in your tap water can devour. DO NOT use ammonia absorbing material to keep it under control - you WANT the ammonia level to spike. Once the bacterial population increases, the ammonia slowly gets digested and released as nitrite, which is also toxic to fish. A few days to a week later, a second species of bacteria consumes the nitrites and converts it to nitrate, which is safe for fish. When the bacteria levels have become established and stabilized, the tank is cycled and it’s safe to slowly add more fish. How long this all takes and how many fish to add depends a lot on the size of the fish and the size of the tank.
Once your tank is cycled, some of my favorite freshwater species are Silver Dollars, Neon Tetras (both red/blue ones and some black ones for variety), Head & Tail light Tetras, Serpae Tetras, Harlequin Rasboras. Some really unique looking fish I like are Glass Catfish, X-Ray Tetras or Scissortail Rasboras. Stay away from Barbs, they can get aggressive and nip other species. I also avoid Gouramis because they are prone to a few weird diseases and usually grow too big for my other community fish (my wife has one that weighs 5 lbs). I also like Green Corydoras Cats for cleaning up uneaten food on the bottom. They do best in groups of about 5 or more. I would stay away from Loaches if you are a beginner. They are scaleless fish and are more sensitive to water chemistry than scaled fish. They are especially hard to treat for common diseases like Ich, because they can’t withstand the right concentration of medication. If you do decide to get a lobster, the loaches would be the first to go since they are bottom feeders and literally right under the lobster’s nose.
Sorry for the short fishkeeping manual - it’s a big hobby of mine. At one time I had 8 tanks in my house with everything from African Cichlids to a Coral Reef tank. After lots of money and an expensive education, I finally decided I like my 30 gallon community of small Tetras the best. 
Thanks for the advice about size. It’s very sensible. However, our lease limits us to a 20 gallon max.
What do you do with the lame fish you buy to start an aquarium? I wouldn’t want to keep lame fish. No lame fish! Give them away? Give them back to the fish store? I couldn’t kill them.
There are plenty of beautiful inexpensive fish that are strong enough to be starters. That’s why I recommend Tetras - there are so many variations choose from and most are beautiful fish that do very well in a community. On the other hand, you need to be prepared for a casualty or two during that first month, so you don’t want to get anything expensive or anything that someone is apt to get too emotionally attached to.
I still have 3 of the 5 Lemon Tetras that I cycled my 30 gallon tank with over 2 years ago.
Zebra danios are hardy fish that you can cycle with (although I myself think fishless cycling is kinder, if more boring) and they’re so much fun! I love my zebras. You have to keep them in a school - I have 6. They’re small but they love to school together, and they’re very fast and interesting. They can’t get enough of swimming on the “water treadmill” current under where the filter output is. Definately not lame fish.
Also not all gouramis grow big - dwarf gouramis are beautiful fish (and that’s their normal color, they haven’t been weirdly bred or anything) that don’t get big. I especially like mine because they provide some interest up at the top of the tank. They do like a lot of plants, though. And I think I might have gotten bad advice about getting two males - they were fine for months but now they’ve gotten a little territorial. It’s fine now that I moved some floating plants so they can each have their half of the tank, but I was worried about the less dominant one for a bit there.
Cichlids are the most colorful freshwater fish, and in my experience fairly hardy and clean. They can be aggressive, and combinations with other fish must be checked carefully. Also choose either African species or South American species to go with because they don’t mix friendly.
I have had them with Lobsters/crawdads before. Never had any problem with them and Cichlids.
I did have one screwy blue lobster, who refused to eat anything but life fish, so I had to go to feeder fish to keep him alive. And once the cichlids got the taste for the half eaten ones the lobster let go, they wouldn’t eat anything else but live either. It turned into a huge expensive mess.
And don’t think Oscars are like other cichlids. They will outgrow anything else in the tank quickly and become dangerous to them.
There are products you can use to cycle your tank within 24 hours. Bio-Spira by marinelabs and Cycle (carried by PetCo and most local pet stores) are a highly concentrated mixture of both ammonia and nitrite devouring bacteria. You add the fish and your Bio-Spira or Cycle and the tank will cycle with minimal stress on the fish very quickly. Plus you can’t overdose, the excess bacteria simply have no ammonia or nitrite to eat and die off. I would definitely look into either of these products if you are a beginner and don’t have the patience to thoroughly cycle the tank–plus its much easier on the fish.
You want easy? You want colors? You want a lot of fish?
Buy 6 male fancy guppies. 12 females. They will be plain.
Sit back and wait. They are very prolific.
You are definitely getting a crayfish. Don’t bother getting anything else until that one climbs out, crawls away and dies.
Then come back and ask for more advice. 
Sorry, but that about the way it is.
Sounds lazy, quick, AND dumbass proof! PERFECT.
Fish that kiss AND kill. Excellent.
You don’t want the kissing kind - like most of my cousins, they look like they’re making out but really they’re arm-wrestling. Also, they get too big. Here’s the kind I have:
http://liveaquaria.com/product/prod_display.cfm?pcatid=974&N=0
They’re cool, they’ve got these long feeler things they like to work around with like a blind person with a cane. As you can see, they only get two inches long, and they’re quite colorful. When I got mine they were very shy, but they calmed down as the surface plants I put there grew.
I very much reccommend live plants - my fish love them, they’re good for the water, and they’re kind of fun all on their own. You need good lights for them though.