Well people say all kinds of stuff on the internet - no filter is possible I suppose but if you have fish you really should have one - both to filter poop, debris, fish food, etc. out of the water.... AND to provide surface for your beneficial bacteria. If you havent already done so pls read up on biofilters and the nitrification cycle which changes ammonia (from fish poop/decomposing organic matter) to nitrite to nitrate. The first two are highly toxic to fish, nitrate is what your plants will need to live on.

Look into external filters of some sort since your pond will be very small - if you want to diy there is a "mini-me" skippy filter, also other similar you can buy already made.

Yes there are ways to have a water garden and/or a stream at the TOP of your waterfall be your filter - that actually would be a very effective more natural-looking way of doing it and maybe thats what you have in mind? The plants growing in and among your filter media would utilize the nitrate in the water from the fish - in that sense the plants and the other media (whether lava rock, bioballs or whatever) would be acting as your filtration .

Re pump size - I'd get a slightly bigger pump , maybe
150 gph (because once you add in tubing to take it up to waterfall its
going the flow will be lessened). You might even go higher gph
depending on the height and length of the waterfall and the tubing (there are charts where you can look this up and
figure it out.)

Last but not least, no more than THREE GOLDFISH. Those tiny fish will grow to 6-10 inch long within a few yrs and 30-50 gallons per goldfish is the recommended minimum. Have heard that rosey red minnows are good for small ponds too - if you want more fish. They are short lived naturally unlike goldies which live 10-20 yrs under good conditions.

No koi - instead you might want to go a pond store for goldies - there are some bred now for ponds which are beautiful with bright markings and long fins.

Thats all I can think of - my first pond was about your size, so Im trying to think of what I wished Id known then. Im sorry to say I lost some goldfish at the beginning because some idiot at the garden center kept insisting I didnt need filtration, just let it "balance out" he said... meanwhile the pond kept getting muckier and muckier.

Yes you do need some sort of filtration, whether a formal product you buy or make, or informal system of plants/rocks. Spoze it could work if you just net or vacuum out the debris and have some
system of doing frequent water change, or of trickling water in and out. With that small a pond its doable, but I cant help but think if you have a pump, why not do
the filter as well and make it easier on yourself.

Thank you so much for your response :) I am sure I will have more questions once I get this going...

I have forgotten the recomended ratio of volume to flow rate, but I don't recall that my ratio was greatly over sized. I have ~800 gal and a 2400gph pump. You certainly don't want to go way over sized because a small fall shouldn't splash all over the place into a small pond. However, a 2 or 300 gph rate would seem more reasonable. That is still a very small flow and would probably work for a 3" spill area. You want to actually see something falling.

I have a mini-me diy filter like C.R. mentioned, but that is still a 20gal garbage can in a hole; not exactly teensy! I'm not sure that it really does much, but that is because I have a long stream that is really most or all my filtering. Plant roots in flowing water become a super filter. For a small pond, I think you could create a two to four square foot area above your pond where water circulated around some plants and that would beat any filter.

FYI: my pond has been running for 9 years. I once cleaned the bottom when I thought my mini-me had a leak and I removed all water, but otherwise I have not cleaned out the bottom. It gets kind of fuzzy grungy looking down there, but the water is completely clear and my fish don't die. Yes, if I pull a lily off the bottom, I disturb a huge plumb of crud that turns the pond into milk chocolate, but much of that crud then gets pumped through and trapped in the stream roots, and the rest settles back down in a few hours.

Thank You !! I know nothing about ponds etc. I am trying to find a pond place somewhere near me I am in Davie Fl. No luck yet. Home depot has large spillways/falls. If I order off of the net I am going to have to talk to someone on the phone to make sure I get all the right equipment for the size.

One other thing to be aware of - the person who doesnt really know much about it but who won't admit it. I seem to have this happen a lot at HD, I think they're told to never say "I dont know." Its a bad sign when you ask a question and they read to you off the box.

Also be aware that manufacturers of pumps, filters etc often overstate the capability of the item - the box will say something is "good for 1000 gal pond" but in reality it might be more like 100. You really have to look more at the capabilities - gph, size, etc.

I would suggest either an online pond supplies vendor with 800 no (shop around to find one w/good rapport) OR.... I really think it is worth cultivating a good relationship with a pond specialist in your state,or a nearby state, even if it's a long drive. You can do a lot by phone or scanning your drawings and emailing, and then taking a trip to pick up the stuff. Once you're a paying customer then they are generally helpful about guiding you through setting stuff up. Yeah you might pay a little more than you might online, but the relationship is well worth it IMHO. Esp. cool are places where they have ponds of various sizes set up, with fish, so you can get a good idea of how things work.

Actually my experience is the local places are generally QUITE competitive with the online prices.... and also w/ HD. HD might have same or SLIGHTLY lower prices but quality of merchandise is much worse - hoses that crack and break, thin flimsy pond liner etc.

HTH!

Chas it is going to be on top of a wood deck. A tiki hut is something that is big here in Fl. The Seminole Indians manufacture them. Mine is not as big as this pic it's like 12ft x 9ft.

Thanks CR ! I definitely did not plan on getting anything for this at HD! I shop in the garden center all the time and I can honestly say no one there really knows anything about what they are selling-they just know where everything is :)

Read the pump box carefully and in addition to the gallons per hour, look for the lift height if you are planning any kind of waterfall. Some move a lot of water for filtration but cannot lift very high. I have about 400 gallons in my pond, and bough the 29 cent "feeder" goldfish at the pet store. Placing them out in late spring, they will be accustomed to the water temperature by winter. They are now 6-8" long, and have survived 8-9 years of freezing over. I made one end of the pond 24" deep, tapering to 12" at the other end, but there has never been more than 2" of ice and they are visible below it. I only feed when they will eat, usually about May-October. Currently I have only a solar powered 12 volt pump that runs only when sunny, but is just enough to lift about 6" to a hollowed out 2" diameter/18" long log, adding some movement and air to the water. I change 50% of the water in spring, no filtering.