I just moved into a house with 5 or 6 person Grecian Spa. I found a service order from 11-08 where they replaced the heater/PAC (whatever that is) and the control panel. It was upgraded to Balboa.
On the receipt it recommended changing the filter.

I tried to access the filter, it has a black plastic? or rubber lid with 2 nubs on it. I turned the hot tub off and tried turning it, to no avail. Should I be lifting up on it, is it not threaded? Or should I get a butterknife and try to break the seal?

I didnt want to mess anything up. Anybody else out there with a Grecian spa or with some tips?

Any chance you can post a picture of it? Sounds like you have pressure side filter. In most cases there is a retaining ring around the lid itself, sometimes with a clip holding it in place. You'll have to unscrew the ring first and then pull the lid (tub off!).

If the lid looks like this one, then this is the breakdown:

Oh no! The picture isnt working for some reason, I just see a little box with a red "x". The black rubber or plastic lid I am talking about has a traditional "skimmer" cover on it that pops right off. I noticed that the black plastic thing sucks alittle air, so I put a cup of spa water in there to seal it completely. I am going over to the new house tonight (still moving) and will snap a picture. Thanks for your help " title="Very Happy" />

Heres the closest thing I could find to the lid.... Mine doesnt have a white handle on it, just two raised nubs. Do I unscrew it or pull upwards? EDIT:Is it possible that my filter is a one piece unit, with no seperate lid, and what Im seeing is the top of the filter that happens to be an integrated lid? :" title="Question" />

Oh, you have a suction side filter, and yes that may be the top of the filter you're looking at. Try unscrewing it.

I did. It refuses to budge. Its in there good, and the nubs that I was telling you about, well they are torn a little (it is rubber) so it appears somebody else tried to loosen it too and was unsuccessful " title="Mad" />

It might be that they're molded in for leverage so you can take something like a 1x4 board and put it between them and twist, but I'd like to see a picture before you go that far just to be sure.

Well I finally accessed the filter...

The rubber "top" was just that - A rubber top. I used a butter knife and broke the seal, it came right off. The filter looked ok, I soaked it in the bathtub overnight with filter cleaner. The water was significantly dirty. Whatever that filter cleaner is, its strong and worked great. The filter looked like new after I sprayed it off. A lot of black stuff came out of it (dirt?).

Now I know what the filter looks like. Its about 30" tall, about 5" in diameter.