I have always wanted a saltwater tank, and have reasonable exoerience in freshwater. I have 2 tanks I could use for this, one is a 35 gal. octagon, the other is a 135 gal. rectangular. They are both glass with plexiglass tops and neither have special lighting right now.

Which tank would be the best for a beginner? I know it's often easier to keep larger tanks in balance, but I'm hesitant to jump into this with such a large tank. What equipment would be best and what is bare bones for each set up? I promise NOT to throw fish in it as soon as it's full of water! I just have a budget :) Thanks for your expertise :)

well it looks like youre not a dumb as most of the people that post that topic... or shuld i say uneducated, thats prolly a better word. In your case youre sort of in a bind, you have choice A) of using your smaller tank which the equipment and sand and rock would be cheaper but not only would your levels be hard to maintain but you would also face circulation issues as well as the fact that fish like to swim from side to side and not so much up and down. On the other hand you have B) which would provide a very good starting tank, it would just cost a little bit more to set up than your octogon would. I would go with the 135 because a rectangle tank is easy to put powerheads in the corners and your set, your fish can swim wherever they want and still be happy too.
Cost for you would be based on....
what kind of fish are you going to have
and
is it going to be fish only or reef?
To give you an estimate i started on my 70 gal as jus FO , then i got sucked into the hobby like a hottie n hugh heifner. So right now i have an anemone as well as a few coral frags and 200$ worth of fish.
What are you planning on spending for this whole setup???

Here's a break down of the things you'll need and the costs invloved.

-150-200 gallon mix to make that much saltwater is around $40 on drsfosterandsmith.com
-sand is around $1 a pound for dead sand, live sand is about $2-$3 a pound. You'll need about 200 lbs or more for a 125 gallon and about 40 lbs for a 35 gallon.
-Live rock is around $3-$7 a lb. For a 125 you'll need around 100+ lbs, for a 35 you can settle with 30 lbs.
-RO water is good to have, you can get it from super walmart (culligan dispenser, RO/UV) for $2 for 5 gallons. A 125 is going to evaporate probably near or more than 5 gallons a day, a 35 is less than 1 gallon a day.

That is just basic setup. So I hope now you have an idea of what kind of money you're looking at spending.

I don't have a set budget, and can DIY some things as long as there are directions. I live about 5 miles from the pacific ocean (Oregon). I don't know if you can use say driftwood, sand or rock from the ocean in a salt water set up, but have used well washed, light colored river sand in a freshwater that has done wonderfully. I put it in a small amount of water and leave it for a couple days, and test the water to make sure it's not leaching unwanted minerals etc. I would have to either boil the sand or leave it to dry before washing it, so I wouldn't be substituting it for live sand. I don't want parasites. Is there any way of doing this for part of the sand?

My financial strategy would be to start slow- get the bare essentials going- filters, pumps, and equioment you guys reccomend, and slowely add more reef and fish as I can afford them. I figured this would give me lots of time to get my adjustments right. So, for a 135 gal., what equipment do you recommend I start with- how many skimmers, type of pump or filtration system (the tank came with a cannister pump good for 200 gallon that has been running freshwater for 4 months. Would that work on a saltwater system?), Anything that you don't usually use for a freshwater tank I should know about?

I would get a good size sump with a mag 5 or mag 7 return pump. a good solid refugium. Canister=useless. They work yes.....but they are super expensive in saltwater. reason being.......the media has to be changed a lot more often than in fresh. To get by in salt.....you have to run something 4 times as big. I ran an aquaclear 70 on a 29 gallon.....So I would highly recommend a sump with a filter sock. In all honesty all you need is a sump/overflow.....filter sock and a really nice protein skimmer. You would be good to go with that setup. with the 135.....I would go with a skimmer like the one in the link below. The ASM is a great brand and it pulls nicely. I have Aqua C. Its great but its too small for your tank. There larger skimmers are through the roof in price.....but im sure they are worth it. dont skimp on your skimmer. that cant be stressed enough. It would be the equivelent of skimping on putting a dishwasher in your new house. Sure you can get by.......but its a pain in the A@#. your water changes would have to be much more frequent without a skimmer. if you dont get anything else.....get a skimmer. I know it sounds like im preaching....I am.... get a skimmer. get a good one. with a tank that size its absolutly necessary. There are other ways to filter out the organic matter that skimmers pull........but they are a LOT more hasle. cheeper.......but a PITA. You could get two mag drive 4's and be in business as far as water flow and current. If you want to get fancy you can put in a closed loop or a wave maker. Its fun to watch corals sway like in the ocean. Basically.....I could write a book......so ask ANY questions you have. any of us will be more than happy to help! and last piece of advice for right now......BE VERY VERY PATIENT!!! :)

nooo don't get the coralife one. I have it and it is sketchy as hell. The water levels all of a sudden drop or go up and overflow. And when I barely try to turn the adjustment dial it will shoot down or back up. It is like this thing has a mind of its own. I don't like it and will eventually get a new skimmer....