New 23 litre fluval edge tank cloudy and dead fish please help

Hi everyone, i am new to the fish world so take it easy with me. I just got a fluval edge 23 litre led aquarium. I rinsed all the gravel rinsed all the filter before i put them in topped tank up. Left it running all that day and the next day and went and got 4 guppys as the pet shop suggested, they seemed happy at first but when i got up this morning 2 of the 4 were dead and the other 2 were swimming in the little square opening (look like they were gasping for air) so i dropped the water 10mm so there is more surface area for oxygen. I have my filter running on max trying to get more oxygen. Also the tank seem really cloudy. Any help appreciated. Thanks Dale

You need to let the tank "cycle" before you add fish.

When I say "cycle" you need to let the filter run, get the temp set, feed the water and let it run for about 10-15 days before adding fish.

The mistake you made is a common problem all new fish keepers make. If your final 2 guppies die, wait the time period above, then add one fish.

Especially with guppies if you have a male and female you dont need more than a pair in there as they reproduce like rabbits!

Best of luck and dont become frustrated.

Cheers mate, yea i did look into doing a fishless cycle which i guess i should of done. My local aquatics(opposite to what seapets told me) said guppies werent the best choice so i put 2 plattys in for now. So got 2 male guppies and plattys. I noticed they were all swimming at the top of the tank which looked like they needed oxygen so i just put a air pump and sponge filter in the tank and the fish are swimming around happy now. I dont think the little opening at the top was fluvals best idea as there isnt much area uncovered so i dropped water 10mm. Fluval say there filter system built in on the edge does 100 gallons per hour (gph) or 357 litres per hour (lph) i personally dont think that little filter system does that much but i could be wrong. Thanks for your help mate if these fish die i definately wont be adding any more until the cycle is complete.