Why do all my guppies die?

I have seen a guppy disease that lingers in the tank and wipes them all out slowly over time... I believe that if you had a problem from one store, they could have not completely cleaned their tanks meaning the disease is still there, I would suggest another supplier, and to quarantine them.

The only time I had my guppies die (not the mollies they shared their tank with) was when I stupidly brought in one from a sketchy store that after I introduced that ONE and they all died, I called and they said all there's were dead too...
 
so sorry to hear about ur loss you are not the first person to have lost guppies in a short space of time. i got 2 females from a lfs an i QT them for a few weeks an they got white spot but alls well i also managed to get some from a friend because all hers were breeding like mad so now i have a male female an 2 other females an 15 babies sooo i recommend u try an get guppies from a good breeder my tank ph is 7 .5 an i never add salt to my tank an babies are going to grow up to be nice fish soo good luck
 
If you are doing water changes and regular maintenance, I wonder if the gobies are killing the guppies (bit of a stretch there). Try getting some guppies from a different source and see if the problem repeats itself. Might be the stock.
 
I agree with the comment about the guppy breeders

Those contraptions seem to cause more harm and stress to the fish then good...I actually used one when I first started keeping guppies and the pregnant female actually started aborting the still growing eggs...just dropping little yellow balls with 2 eyes and I immediately removed her from the contraption and it now collects dust in my box full of unused ornaments etc...

I had the exact same issue with my guppies about 2 weeks ago and the only thing that I can attribute it to is dirty water

I'm not sure how valid this is to your situation...but in my case
I always vacuum my gravel on a weekly basis...50% one week, 50% next week and the 3rd week the carbon gets changed and no gravel vac

Before I used to siphon by just dumping the siphon down ... move 1 inch up rinse and repeat...

Problem that I was having is the mulm actually settles right into the substrate itself and makes it so solid you actually feel like you're hitting the bottom of the glass...but not the case

I know this is foolish to be explaining but I had the exact same thing happening to me and went NUTS with the gravel vac...only thing we could think of was baterial infection due to dirty water...and boy were they right

The junk i removed from the substrate smelled so wretched and was so brown...I'm 99.9% sure that is exactly what was causing them to die

Needless to say the problem is resolved now and I haven't had any more casualties (knock on wood) for the past week and a half now

Edit: here is the thread in case you want to compare

http://www.aquariacentral.com/forums/showthread.php?t=217207

And I apologize if this is common sense to you...took me 7 guppies to finally figure out how to properly clean the substrate
 
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