I am looking to start a fish tank and wondering what are some colorful and active fish to have

just start whatever you feel like. but whatever you do - dont buy goldfish. these animals are so messy and you find yourself cleaning the tank loads. i reccommend some sucking catfish {aka. chinese algea eater}, and with it some black widow tetras {aka. black tetras} and a few fighting fish {siamese fighting fish}.

I'd say to go with livebearers (guppies, platies, swordtails, mollies) & maybe a betta. All of these r very colorful, active, & hardy if u give reasonably good water quality & temperature. Livebearers do give live birth, so u may even see some babies (although the other fish will probably eat them).

I see someone already beat me to the elmer is website recommendation - it is a great source of info. Here r a few more. These also have the info you're getting on cycling ur tank:

http://fishlore.com/TropicalFishProfiles.htm
http://fishlore.com/NitrogenCycle.htm
http://totallyfish.com/tips/newtank.html

in my opinion a 20 is good for a starter u dont wanna go too big. u need to cycle the tank first or ur fish may become stressed & die during cycling. to stop this put ur water ,plants, water filter, air pump, & gravel in the tank & let it run all the time for a few weeks(2+). to start the cycle a source of ammonia is needed so feed the tank some sprinkles of fish food daily or u can put in pure ammonia. in a fish tank ammonia is put in by food, waste & fish. ammonia will kill ur fish if u let it get too high. by putting the ammonia in from the food & not the fish no fish get harmed & ur tank cycles. now as i sad feed the tank fish food daily. the ammonia will develop then bacteria will develop to turn the ammonia into nitrites then nitrites will turn into nitrates(a much less toxic form of ammonia). u can get a master test kit at any pet store. this will have liquid testing for ammonia & it runs u about 30 bucks but its a test kit for ph, ammonia, nitrites & nitrates. i recommend liquid tests because test strip colours run & r hard to tell whats what. anywho, test ur tanks ammonia after the 1st week of feeding it. then the 2nd & maybe even a 3rd but for a 20 gallon no more than 2 weeks & the bacteria should be doing its job. then its safe to put in fish.

i find that most fish r schoolers, they love to be around fish of their kind so try to get all of one kind as in tropical, cichilids etc. i have a 55 gallon freshwater & i find catfish r very wild. they r always swimming & they spotted & the wiskers r so cute. i also have some red finned sharks. iridescent sharks & bala sharks r also cute. but since u r keeping ur tank at 20 gallons u will need fish that dont grow so large so i suggest some mollies, korydoras or my favorite-the tiger barb. it is silver red & black striped of course & small. they never leave one anothers side if u see one u see all 4 in my tank. also, korydoras r bottom feeders & will help keep the tank clean. u can tell this by noting their mouths r pointed & located on the bottom of their nose area. those r the most colorful fish i can think of for a 20 gallon fresh water tank. saltwater has soooo many neon colored fish but salt is hard to manage so for a starter id go fresh water.

I am assuming ur meaning tropical / fresh water.
For limited space a 20 gallon tank is fine. But, as ur enthusiasm grows so will ur need for a bigger tank (your choice to go bigger). I would say start off with a male Betta, a clown loach, & a pleco. I would suggest some drift wood (size of ur tank will determine the size of the driftwood).
REMEMBER to cycle ur tank for at least 72 hours before introducing any fish (substrate, water, filter, & decorations) & run ur filter for the same 72 hours.
Sorry for the long intro .. yes u should only introduce a few fish at a time & then wait a few weeks before introducing more to ur tank mates (BIO reasons).
Tetras, dwarf gouramis,and a dwarf african frog would be a nice addition to the above recommended, actually 2 or more clown loaches will be very enjoyable to watch.
Depending on the age of ur Son . make sure u have a VERY Sturdy stand, for the safty, first most of ur son. Boys will be boys.

Honestly u r best cycling the tank without any fish. Or starting with hardy fish & adding no more than 1 per 10 gallon per week, watch the ammonia/nitrite/nitrate levels carefully, be prepare to do massive water changes or lose fish.
http://fins.actwin.com/mirror/begin-cycling.html

As far as starting fish. The 1st thing I'd do is test ur water is pH, & hardness. If it is below 7 pH, & soft (Below 10 KH) u should look at soft water fish like tetras, cory cats, & danios. With high pH, & hard water u should look at the livebearers guppy, platy, swordtail, & molly. Also a single dwarf gourami is good for most water, but should a late addition.

If u r starting with fish, & not cycling 1st. A betta is a good fish to start with as they r pretty tough. Females r more peaceful, & get quite colorful once they r in a tank & not stressed. Males r generally do well with fish that do not look like bettas, or r really slow moving in a tank larger than 5 gallons. (IE male fancy guppy) Also if a male betta get out of line u can just put him in a breeder, or isolation box. He should get over new tank mates in a week or 2. Just remember betta, unlike most fish, need to be able to reach the surface of the water to breathe.

Make sure u cycle ur tank first, u can do this fishlessly with adding ammonia until u have a 5ppm reading, then waiting until it drops to 0ppm, then having a nitrite spike, then that drops to 0ppm. When both read 0ppm, ur tank is cycled, do a large water change, then add about 3 fish every few weeks. This allows the bacteria to adjust to the bioload of the fish.

Some good beginner fish:
Platies
Swordtails
guppies
Black/White Skirt Tetras
Gouramis (can be nippy, 30 gallons is better for larger species)
Betta (only 1 male per tank, watch he does not get his fins nipped)
Checkered Barb
Cherry Barb
Rosy Barb
Danios
White Clouds
Cories
Some types of tetras (neons r pretty but very delicate)

Stay away from the following unless you're getting an absolutely enormous tank:
Pacu (get up to 36'' long)
Oscar (get up to 13'' long)
Iridescent Shark (get up to 36'' long)
Most shark species, unless u get 55+ gallons
Bala Sharks
Tinfoil Barbs
Common Plecos (get 24'' long)
Clown Loaches (get 16'' long)
African Cichlids (require specific water conditions & r VERY aggressive)
South American Cichlids (get LARGE & aggressive)
Koi (only belong in ponds, get 36'' long)
Arrowana
Knife fish

Tiger barbs would be nice for a species only tank, & there r 3 varieties u could mix & match, but they can be aggressive with other species.

Do research ahead of time, & do not believe everything the pet store people tell u (some r good, some r morons). Good luck & have fun with ur tank!

A 20 Gallon is fine for tropical fish. Here r things u will want to buy along with the tank.

1. Tank
2. Hood w/ a light
3. A stand- if u do not already have something to put it on
4. Filter - Aqua Clear works great
5. Water Conditioner
6. Gravel - many colors to pick from & a 20lb bag
7. Heater
8. Plants & things for the fish to hide in.
9. Tropical Fish food
10. FISH

OK. now let’s talk about setting the tank up.

You want to have the tank & stand set up away from windows.

1. Put the tank on the surface it is going to be on
2. Rinse the gravel with hot water. (You want to get all the loose coloring off)
3. Place the Gravel in the tank
4. Place Plants & hiding places in tank
5. Fill tank with room temp water
6. Add Water Conditioner
7. Hook up filter- (you want to put some water in the filter to get it started)
8. Turn on the heater to 70-75*
9. Put on the hood & turn on the light - make sure u cut the holes out in the lid for the filter & heater

Ok now that everything is all set up u want to let ur tank run for 48 hours. No fish in it yet!

Once the 48 hours is up take a water sample to the pet store & they will test it for u to make sure ur water is ok for ur fish.

You want to only get about 2 to 4 fish to start u off & I would stay with tropical community. All tropical community needs at least one buddy & they come in all different colors & shapes.

Once everything is set up & u have ur fish there r some more things u need to know.

1. Only leave ur light on for 8 hours a day - when it is light outside
2. Feed ur fish twice a day - just a pinch of food each time
3. In a months time u will want to add a pleco or a few snails - for cleaning purposes of missed food & algae
4. Also every month u need to change ur Filter Cartridges
5. With changing ur cartridges u will want to change 25% of ur water as well & clean the gravel - u can use a python - http://petsmart.com/global/product_detail.jsp?PRODUCT%3C%3Eprd_id=845524441776792&FOLDER%3C%3Efolder_id=2534374302030062&ASSORTMENT%3C%3East_id=2534374302023693&bmUID=1169522114106&itemNo=0&In=Fish&N=2030062&Ne=2 it hooks to ur sink to make an easy spill free clean.
6. Remember to add ur water conditioner when filling the tank back up with water

Good luck & I hope u enjoy ur tank!

Yes - definately cycle your tank first. Once you have healthy levels start out slow by adding your hardiest fish first.

My favorite community fish are:
Cardinal tetras
Dwarf Gouramis
Mollies
Dwarf African Frogs
Danios

I have all these fish together at some point and they are such wonderful peaceable, yet active, fish.

Good luck - fish are a great hobby!

Well it really depends, if you get a saltwater fish tank it is more work and the fish seam to be more aggressive. But with a freshwater tank, get fish that wo not get too big for their tank and fish that are the same size, otherwise they will eat each other. Shrimp are cool, they crawl around the bottom and clean it alittle. But goldfish can be cool, especially when they are different colors and shaped different.

Ask a pro because a lot of fish ar not compatable.They will attack each other if the wrong ones.

You will need to read up a bit on cycling the tank, which can take around 4 weeks unless you want to use the new biospira stuff that does it in a night. aqua-reliable.co.nr for more.

Some fish I would recomend would be any tetras, zebra danios, barbs, elmersaquarium.com is a good site that has all good info on compatibility and fish.