New aquarium but 1 strange guppy

[irb]

I have started a 29 gallon freshwater aquarium, i had a 1.5 gallon aquarium with 2 rosy reds and a pleco everything good. With this new tank i was kind of nervous at the beggining i started with the water and the filter running on thur the 12th, sunday the15th i added nutrafin, conditioner and start zyme (i used those for the small tank, and never had a fish die) and i ADDED fish the 15 th as well, 4 danios and 1 fiddler crab. So anxious to add more fish todAy the 19th i added 4 guppies and 2 fiddler crabs. I know i did everthing too soon but all fish are fine except for 1 guppy it just laying at the bottom and i dont know whats wrong. At the store a lot of fishes were on the ground i guees dying soo its making me think maybe i got the wrong fish... I dont check the water with kits or anything like that... what should i do.?

 

[derail]

Ouch, definitely started a bit early, especially with a fish in cycle. You'll want to add about half your stocking capacity after about a week, and gradually add the rest. I digress.

More than likely, the guppy could be suffering from high ammonia, nitrates or nitrites. Need a little more description. Is he gasping for air? Having trouble swimming?
Also, when you purchase fish, I avoid buying then from tanks that have any fish that appear unhealthy, just in case.

Provide some more details please, and please get a test kit asap

Let me add some stuff you can dio now. I recommend a partial water change, about 50%, and after a day, a smaller one.

 

[Mumma.of.two]

Please purchase a test kit. I'd recommend the API master freshwater test kit. Avoid strips they are know to the highly inaccurate. First thing you need to do is a large (50%) water change on the tank. The cycling products are snake oil IMO. They either contain the wrong type of bacteria or the bacteria is dead.
http://www.aquariumadvice.com/forums/f15/guide-to-starting-a-freshwater-aquarium-186089.html
Please read this. It contains links to fish in cycling techniques.
Any questions don't be afraid to ask!

 

[irb]

Thanx... I will purchse the kit tommorow... Now there are two guppies on ground one seems to just lay there without swimming but if u get close it swims quite quickly and the otherone is anout an inch above the rocks and swimming in place. I also noticed the fins are nipped, they are breathing fine though but all the others seem fine in middle or on top... How can i do a water change i cant just put tap water right.? I have filled some gallons of water ans hopefully letting them sit for about a week so it can be declorinated or should i just add the conditner in the gallons, and then do the water change... ?

 

[Mumma.of.two]

Add enough conditioner to the tank to treat the whole tank and add the water straight in. Make sure its roughly the same temperature as the tank. I recommend prime for dechlorinating and the API master test kit.
I would do a large water change ASAP as a precaution.

 

[TheMurrays]

If their fins are nipped it's probably from the fiddlers. The crabs probably could not catch the fish if it was healthy, but if it's just laying there... Fiddler crabs actually need brackish water. They will live maybe a month or so in freshwater, and some people have had them for longer, but in the wild they live in brackish. They also need air. Sometimes they climb on a filter or something to get that, but the ideal set up for a fiddler is a half land, half water tank. Just something to think about.