White Spots query/General health info request

Hi all. New to the forum - also new to growing My first attempt, I have 5 plants growing. They sprouted about 4 weeks ago... Correct me if I'm wrong, but I'd say they are in the late Seedling/early Vegetative Growth stage. I couldn't tell you exactly because I'm not as experienced as most of you probably are.

They are grown outside in near-perfect conditions I would say. In the southern hemisphere spring is well and truly here and summer is just around the corner. I have been watering them 2 of every 3 days on average - the plants shares a 3 litre (3/4 gallon) watering can of water between them, which usually leaves the soil in each pot quite most for the majority of the day - drying up towards the end of the day. Also on Monday I gave them a feed (a liquid based plant food - all pictures of plants and food I am using are below). It says on the bottle to only use once a month. I am going to follow that - unless someone else can correct me on whether I should be doing it more/less frequently.

One of the plant's leaves are starting to brown, and the leaves on 2 other plants have developed these kind of white-spots. They don't look like mold (although it could be) or anything else I've ever seen on a plant to be honest.... but rather look like tiny droplets of white paint on the leaves. There's hardly any of the spots... And after a long list of google searching I was unable to find any solid answers. Lots of problems and solutions for them similar, but I thought it was best to seek advise from those who may be more help than google and a bunch of random websites. I would prefer to get a solid answer now so I know whether to act on it, or whether it's a problem/disease that's only going to get worse. So I appreciate all your knowledge and wisdom

Here are the plants with the white spots:
Image 1: http://i62.tinypic.com/34ys6tf.jpg
Image 2: http://i61.tinypic.com/2my96o9.jpg
Image 3: http://i59.tinypic.com/igw4l5.jpg

Images of the front/back of liquid plant food I used:
Front: http://i60.tinypic.com/2po75vc.jpg
Back: http://i59.tinypic.com/161jbef.jpg

Thanks. If you need anymore information or pics, just let me know and I will reply/upload with what you need.

Thanks again so much for any advice/help anyone can give me. Hopefully one day I will be able to pass the same advice on to someone else who needs it

can't see pics but could be spider mites. if so, look under the leaves (the ones with white spots) and check for small white/and or black spiders. VERY SMALL. but if this is the case, get some azamax or mighty wash and spray the whole plant. Not sure how much this will help since it is out doors and the little bastards could be everywhere.

I agree with Benelli. But could also be Whiteflies, which also live on the underside of the leaves, and also leave white spots upon the leaves.

Best bet is to look at your plants with a scope. Spider Mites look like little spiders and whiteflies resemble tiny moths.

Luckily, Azamax can be used for both problems.

Kind of looks like mildew...do you have a microscope? If not, get one and take a look.