Who is OP? I was addressing ggburke question on filtration for a 75g tank and bigger tank later with the use of the same filter without changing nothing.
IMO: He wants a filter that will be enough filtration for a 75g tank now and is planing to buy a bigger tank in the future an be able to use the same filtration.
Then the OC has a 3/4 inch line witch would be good for his tank. The Nu-Clear filter has a 1 inch line witch would need a bigger pump 1000g an over and are best for tanks up to 180g .
There are people that use the OC for a 180g tank also. All he needs is a good Pressure Pump and put a valve on it to throttle the flow down. He can get a good Pressure Pump from 600g up to 900g
I would like recommendations: I would like to purchase enough filtration to handle my needs now and in the future and if possible be able to adaptable to future innovations without purchasing new filtration.
The NU-clear canister idea intrigues me. I have more questions, if I may: How big a pump would I need? Can I make the plumbing out of regular PVC or better yet black ABS? Is PVC cement aquaria safe? Which inline heater do I use? Lastly, can you use a CO2 diffuser with this setup?
ggburke you can use regular PVC or go with hose also, You can also get a good size High Pressure Pump, I pick up on Ebay a used Blue Line 55 HD Pump for $85. just shop around. Check out this site witch a lot people use this filter you can seek answers there also: http://www.barrreport.com/
For Heaters I found this place that sells a module that can be use with a 1 inch line an use a Titanium Heater. I'm going to do a DIY CO2 Reactor with a 1 inch in/outlet , I'm going to Y split the line from the pump 1 to the filters, Heater and the 2nd to the co2 reactor and UV light then back together.
And here is where I bought my Filter and I'm going to get a Gamma UV Light with a 2 inch slip also from here , They have some good prices. http://www.aquarium-supply.biz/ for pumps there is http://www.championlighting.com/home.php?cat=485 and keep an eye on Ebay also, Check your Local fish Clubs that have a For Sell
forums even if it's a Reef Club, I sell all my use stuff in http://www.bostonreefers.org/forums/