Yes you do have lots or problems with your tank you do know. heres my questions
1. what type of plecos
2. you need more tiger barbs and swordtails since tiger barbs are schooling fish and swordtails and other livebearers do much better with company
3. mollies do best in brackish and do not thrive in FW
4. you do know there will probably be a lot of aggresion with your shark and tiger barb
most of these fish were gotten before I had a clue about fish keeping. but they are reg plecos..I know they get huge our original one has knocked over plants. but I have been scared of adding more swordtails or tigers...I am told tigers become more aggressive in groups
Mollies do absolutely fine in freshwater. Mollies are very versatile fish and as far as I know it's all where they originated from that determines where they do best. Most colors originate from somewhere else. Darn genetics
Your tank looks very nice! Your pleco in the picture looks like mine which is a common pleco. They can grow over a foot. Escpecially since you have 2 of them (I assume both are the same species), they will probably become monsters in your tank knocking things over. You can try and trade them in if you like at your lfs. Many pond owners love the bigger plecos. If you decide to go this route, check out and use the word bristlenose in a search. These plecos rarely get bigger than 6 inches, and some stay as small as 3 inches. When you find the fish you want, check on on a regular basis for someone selling them possibly in your area, or you can always have them shipped. You can also check into seeing if there are local clubs in your area, and find out what the locals have for sale or trade. I love getting my fishies from local hobbyists. They are more special, and you know they were probably well taken care of. Your tank is very pretty just the way it is! However, if the plecos become beasts in your tank, now you know what you can do about it. Of course the other option (and one we like a lot here), is to get a bigger tank in addition to the one you already have!
my pleco (its a common > my friend gave it to me, I was going to get corys...sigh) has competely shredded several of my plants, now all that's left of them are little bits here and there
I like corys soooo much better. I never even see my pleco at all!
Why don't you give your pleco to the lfs and get your Cories, Emma? You're going to have to do it anyway sooner or later... :-\ And I love Cories too, I wish I could get some.
Oh yeah, and what are lake minnows? I've only heard of white clouds.