I'm sorry...that sounds like a pretty typical pet store answer.
Did you only have him test the pH? If you didn't ask them to test the rest and didn't get a test kit, then I'd suggest taking a sample back and asking them to test your Ammonia level, your nitrite level and your nitrate level. Ask them to give you the results in numbers...not "they all look good" or "you need this product to help this one because its high". I'd suggest writing the results down and posting them here and we can help you interpret. The other thing you could do is look at their test kits...the master one has some stuff you dont necessarily need...so you can buy those three seperately. They're usually like 6 or 7 bucks each I think.
btw where your pH is on the scale really doesn't matter. If its naturally right in the middle at like 7 then thats awesome...but if its not, its ok. Fish will adapt to pretty much whatever pH you put them in, as long as its relatively stable. Of course the only way to know if its stable is to have the kit and test it on a regular basis...but at least you know that its somewhere in the middle if he told you its not too high.
Algae remover is usually also a waste of money. Its like putting a bandaid on...because even if it treats it now and it works...you didn't take care of the cause of the algae, so it'll be back! You need to do some reading on the boards (use the search function) if you have an issue with algae and see if you can figure out what the cause is. (sunlight, overfeeding, ammonia, too high level of nitrates etc)