fancy guppies

Question
First of all, I purchased a pair of fancy guppies from our local fish store (they only sold in pairs, even though I know that people suggest a 'trio') and my female NEVER had any offspring. I checked almost daily and kept an eye on her.
She is still alive, but does not have any appearance of being pregnant.
Could the fish have been 'cheap' fancy guppies since I bought them for about $5 I think at the fish store?
The male that I had just died a few days ago...i am unsure of the reason.
Could this death have anything to do with a high level of acidity in my 20-gallon tank? (approximately 20 gal...not 100% sure)
I do also have other fish in the tank, including Cardinal tetras, an algae eater, and another species of small fish. (I forgot the actual name).
Also, the filter that I own does not seem to be working properly. It just 'dribbles' out water, instead of pouring water like it should.
I want to purchase a new small fish tank just for my fancy guppies (I would purchase more guppies, of course). What type of tank would you suggest? How many guppies do you think I should purchase (also, how many of each gender)?
Also, I want to purchase a Pennplax Aqua-nursury for my pregnant guppies (once they become pregnant, that is). However, how long can they stay in the nursury? Because if I see that my pregnant guppy looks very large, I will not necessarily know exactly when she will give birth....so I would want to put her in the nursury 'just in case'. But if she doesn't give birth during that day (since i work in the daytime...I would not be able to check on her during the day)...how long can she stay in the nursury? If she doesn't give birth that day, should I leave her in there in case she gives birth the next day?? Or put her back with the rest of the fish?
And, should I feed the pregnant guppy while in the breeder? Or will that cause too much 'pollution' in the nursury, since leftover food would have no wear to go?
What would you suggest for the filter issue, the acidity issue, and the guppy issue?

THANK YOU SO SO SO MUCH!!
-Chloe

Answer
Hi Chloe,
(my female NEVER had any offspring. I checked almost daily and kept an eye on her. She is still alive, but does not have any appearance of being pregnant)

*Maybe she is either still too young or maybe it hasn't been enough time yet. It might help to ask the petstore if they know how old their guppies are. Most fish can breed at about 3 months of age.

(Could the fish have been 'cheap' fancy guppies since I bought them for about $5 I think at the fish store?
The male that I had just died a few days ago...i am unsure of the reason. Could this death have anything to do with a high level of acidity in my 20-gallon tank? (approximately 20 gal...not 100% sure)

*You can't ever know the exact quality of the fish you get at the store since you don't know their genetics. The best you can do is make sure they look and act healthy of course. If the water's pH was very low and the guppies were not accustomed to it (and the petstore water was different) that could have played a big part in the loss of the male.

(Also, the filter that I own does not seem to be working properly. It just 'dribbles' out water, instead of pouring water like it should)

*I have this problem all the time. ;-) First make sure the filter cartridge is not clogged. It it is clogged then rinse it moderately in  a bucket of tank water. If it still is clogged after rinsing it and the filter barely pours, replacing the cartridge is best. Another very important thing to check is your filter's impeller. Make sure the piping and the impeller is clean and free of algae and other debri that can slow water flow greatly.

(I want to purchase a new small fish tank just for my fancy guppies (I would purchase more guppies, of course). What type of tank would you suggest? How many guppies do you think I should purchase (also, how many of each gender)?)

*A really good size for guppies is a 20-gallon long tank. Larger is always better of course. But a 20-long is minimum. You can get by with a 10-gallon just fine however as long as you don't allow the population to grow too fast and keep their water quality good. Guppies are best kept in trios of one male and two or more females. Just always make sure females always outnumber males and watch for any bullies. ;-) Try to keep about a trio of guppies per 2-3 gallons. It all depends upon their maintenance. How many water changes you are willing to do. Guppies really do great in a species tank. But they do mix extremely well with corydoras catfish and/or Otocinclus.

(Also, I want to purchase a Pennplax Aqua-nursury for my pregnant guppies (once they become pregnant, that is). However, how long can they stay in the nursury? Because if I see that my pregnant guppy looks very large, I will not necessarily know exactly when she will give birth....so I would want to put her in the nursury 'just in case'. But if she doesn't give birth during that day (since i work in the daytime...I would not be able to check on her during the day)...how long can she stay in the nursury? If she doesn't give birth that day, should I leave her in there in case she gives birth the next day?? Or put her back with the rest of the fish?
And, should I feed the pregnant guppy while in the breeder? Or will that cause too much 'pollution' in the nursury, since leftover food would have no wear to go?)

*One of the best ways to breed guppies is to move your pregnant females into a special 2-5 gallon aquarium designated as a fry tank. Have the tank well planted with a gentle filter and heater if needed. After she has her babies, you can place her back in the main aquarium.  And raise the fry in the smaller tank.

*Or a really good method you can try is making the main aquarium well planted and provide plenty of large bushy plants for the fry to hide. The fry can stay out of harms way and find little bits of food in the plants. Eventually the adult fish get use to the babies and if the adults are well-fed, they often will not even attempt to eat the babies. So try to thickly planted tank method first before using breeding traps. Breeding traps are famous for stressing pregnant fish and causing abortions even. :(

Best wishes and I hope this helps!
Karen~