Hi again,
A pH of 'fine' doesn't tell us much. Ph can range from 3 up to 10 - all is 'fine' but only certain fish can be kept in those kinds of readings. I'll try and explain a bit better for you seen as this is all new to you.
Firstly water chemistry isn't my expertise and so if I get anything wrong someone please correct me.
The water that comes from our taps can be hard or soft. This is often dependent on area. Here in Yorkshire it's generally soft to very soft. I know someone in Halifax with a natural pH from his tap of 5,5. He has no gH (general hardness) or kH (carbonate hardness) meaning that the pH in his tank is subject to possible swings and this is very dangerous for the fish. A stable pH is good for the fish - wild swings are not. There are ways to deal with this but it's far too complicated even for me to get to grips with so I'm not going to frighten you with it right now.
So. Our fish come from various differing climates. Some fish (mostly those from South America) live naturally in very soft water and low pH, gH and kH and so are great for those of us living in a natural soft water area. Other fish come from places such as Africa or Asia where the water naturally is harder with a high pH, gH and kH.
Your lfs telling you that your pH is 'fine' doesn't help us to assertain what type of water you have and what level your tank is running at. A tank with a low pH can take longer to cycle but if it's really low Ammonia presents as Ammonium which isn't toxic to fish and won't kill them. If it is running at a neutral pH (pH 7 is neutral) then it will cycle well. Below that and it might take a little longer.
If you ask your lfs to test your water again (before your own kit arrives) then ask them to write down the readings. That way you can bring them here and we can see what you are dealing with.
Most local stores are really good but some will say 'oh that's all fine' and send you away not knowing you've got a toxic level of something. Basicly some of them care about the fish they are selling you and want them to be kept in a non-toxic enviroment. Other's don't give a Darn because all they care about is profits.
I've never visited the lfs you speak of. I'm over in Harrogate in North Yorkshire. I have a handful of reasonable stores this side of Yorkshire but only one of them has my 100% trust.
On a side note - Harlequins are a soft water fish so you have chosen well there. Other soft water fish are tetra's, South American cichlids such as Angelfish, alot of the catfish such as the Ancistrus catfish and Corydora's too. There is in my opinion much more choice in soft water fish than in hard water
Hope I havn't overwhelmed you with too much complcated info. I've tried to keep it simple but water chemistry isn't the easiest thing to get to grips with - it still confuses me and I've been keeping fish for years!
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