As has been already stated a few times, do not use fish to cycle an aquarium. You are new to the hobby so I'm going to assume no one has told you about the aquarium cycle and what it is (most pet/fish stores do not mention it unless you ask).
Here is an article that explains it all and I highly recommend you read it. It will explain what the cycle is, and ways to do it without fish: http://www.tropicalfishkeeping.com/f...m-cycle-38617/
The best course you can do is ask the LFS if you can return all the fish for store credit until your tanks cycle, then go in and get your fish. If they won't do that, do not buy any additional fish and continue with the fish-in cycle, changing the water daily.
In regards to your pH what fish do you intend to keep? A lot of people have the misconception that anything other than a pH of 7.0 is bad. That is not the case. Some fish like acidic water (5's and 6's) and some like basic water (7's and 8's). You should test your tap water to see what it is, using chemicals to adjust pH is a futile effort that will do nothing but stress your fish.
Now for algae, this usually happens from two main causes. Nutrients and light. Excess nutrients come from too much fish food and not enough water changes. You should replace 25-50% of the water in each tank every week. Pick a day and make it a routine, shouldn't take you more than a half hour to do. Be sure to use your water conditioner to remove chlorine.
The amount of food you feed should be however much they will completely eat in under 5 minutes. If any is left over after 5 minutes, you fed too much. Most people over feed their fish.
With light, you should only have your aquarium lights on for 8-10 hours a day, and your tanks should be kept out of direct sunlight at all times. A household light timer, the kind you use when going on vacations to turn table lamps on is extremely useful to control your tank lights.
What kind of algae are you getting? Green, brown, hair like, tiny green specs? If it's cloudy/foggy looking water that's just a bacterial bloom that is very common in new tanks. It's harmless and goes away on its own.
Another great way to combat algae is live plants, they can out compete algae for nutrients, and from your post you have some. Do you know what kind? Unfortunately a lot of fish/pet stores will sell plants that are not aquatic and will die if submerged after a few weeks. However, plants need 'food' too, a liquid fertilizer is usually needed and most here recommend flourish comprehensive because it contains all the nutrients plants need. In addition, plants grow best under proper lighting. Typically all you need to do is switch your bulbs over to a 'daylight' bulb with a color temperature between 5000-7000K.