CO2 for a 5ft tank?

[Aquarium_Lover04]

I have a Juwel Vision 450 tank which is 5ft long, 2 foot high and at its widest point, 2ft wide. It holds about 450Litres(110 gallons). I have numerous plant species and fish(including discus). Other info can be found in my thread(linked in signature).
I dose excel as my 'carbon source' although I have been looking over running costs for the next 3 years and it is A LOT of money!! I was considering going for a CO2 system although I haven't got very good advice from my LFS. It is a big tank so a decent system would be needed, and at least 2 diffusers on either sides of the tank. I know it will have a high initial cost, although my LFS does refill for a reasonable price.
This would be my first CO2 system so I am not quite sure where to start. Any advice on good products for this size tank? Also, I keep my pH at 6.4 although the tap water is at about 7.2. How can I introduce CO2 without shocking the fish?(might be thinking too far ahead, but it could wipe out a tank full of $400 worth of fish)
Any help is greatly appreciated!!

 

[aqua_chem]

I read the title of your post, and the first thing that popped into my head before reading any of it was "anything but Excel"


Before suggesting anything to you, I have to ask: what kind of a budget are you thinking for this? Like many things in aquariums, this can be done 'ok' for $ or be done well for $$$.

 

[Aquarium_Lover04]

I read the title of your post, and the first thing that popped into my head before reading any of it was "anything but Excel"


Before suggesting anything to you, I have to ask: what kind of a budget are you thinking for this? Like many things in aquariums, this can be done 'ok' for $ or be done well for $$$.

I don't mind spending $$$ if it is gonna be done well, its pretty much a big initial cost with a low running cost. Obviously if costs can be cut somehow its a bonus, but I dont want any issues with cheaply bought plastic equipment ect.