No special fittings needed...however...
Ronco makes exceptionally good tanks, but they're a little shaky when it comes to plumbing...until the last couple of years they were offering corrugated hose that requires cuffs in their catalog. However, the problem with 1.5" PVC thread-barb fittings is, nominal 1.5" threaded by 1.5" barbed is ACTUALY 1.5" threaded by 1 5/8" barbed (I have NO idea why, it's just the plumbing industry standard for 1.5" PVC fittings)...which makes it a real bear to get a hose onto 'em--especially a hose as stiff as SeaLand OdorSafe. Nylon fittings don't suffer from the same anomaly...they're true 1.5" thread-1.5" barbed. The only real problem with ANY hose is tight bends. No hose should be forced to bend more than it will bend easily. Hose should NEVER be heated to bend it, because that can weaken it and cause it to collapse--kink--at the bend...sometimes after months of use. Obviously, softer hose will bend further than stiff hose, but no hose should be forced to bend. When faced with a tight bend, it's necessary to break the hose and insert and inline radius fitting--and those can be hard to find. SeaLand offers a full line of inline fittings--tees, wyes, radii... However, the only parts of 'em that aren't available at any hardware store or plumbing supply for about 1/4 of SeaLand's prices are the hose connectors that have be cemented to the radius at each end. The only source I've ever found for those is SeaLand. So if you don't have any tight bends between the toilet and the tank, go with the nylon or marelon fittings for Shields 148 hose. If there are bends, give SeaLand a call at 800-321-9886 for their Retail Products Guide...there's a whole page of their fittings in it. Caution: 1. When threading ANY fitting to ANY plastic tank, don't use ANY sealant...only teflon tape. 2. Do not overtighten threaded fittings--go no more than one full turn past hand-tight, plus enough to aim an elbow in the direction you want it to go, even if a lot of threads are still showing. Reason: tank fittings are NPT (National Pipe Thread) standard, which are slightly tapered--so slightly that you can't see it...overtightening puts stress on the female "collar" in the tank that'll cause it to crack. Not always immediately, but inevitably. 3. Don't run a hose off a tank at an angle that can put stress on side of the female fitting in the tank...tank fittings are spin-welded (a kind of heat welding) into tanks...too much stress can break the weld loose. Use a 90 or a 45 if necessary.