Backyard Aquaponics
A place to discuss aquaponics

Greetings. I'm Joel and we just bought a house that came with a raised deck pond. The previous homeowners said they were pretty successful in keeping goldfish in it, even wintering them there. I've drained and mucked it out as best as I could and am at the point where I'm trying to make some decisions about it.

It wraps three sides of a small deck and is about 33 inches from front to back by 63, 53, and 33 inches on each "leg". There is about two feet below ground. I'm estimating the volume about 500-550 gallons.

They left a pump and small box filter behind, with a lot of chemicals and some "fish food" in an unlabeled canister.

There's a "bridge" through the middle, but it essentially goes nowhere. They put a fence across the pebble walkway to the shed for some reason. I've actually been looking at aquaponics and am planning to build a stand behind the bridge for two grow beds. I just have to figure out where and what to get for trays.

I know I have to get started with the fish first and get the nitrogen cycle going. But that's as far as I've figured out.

I figure I'll start with goldfish for my son and maybe change to tilapia at some point down the road (can they cohabitate?). So, how many can I start with? What sorts of plants do I need? HALP!

Welcome JetSmooth! That looks like an awesome fish tank. To keep with the aesthetic, you might build the growbeds out of wood, and line with EDPM liner, the same stuff used to line your pond.

That's an idea I'd not thought of. Much more flexibility with the sizing then.

Is there a good guide for matching growing beds size to pond size? I'm almost concerned with a pond this big, I'm going to need more growing space than I can keep up with.

I may do a few temporary tubs to try out before I go full-bore and build something out. I was looking at the Rubbermaid stock tanks at 50 gallons each.

Thanks!

So the only real guide to go by when it comes to sizing, is the number of fish you can have for the volume of growbed. You can have a huge pond with a couple of fish and a small growbed. With experience, you could push the stocking density with a ton of growbeds. There is a ratios thread. I think it is stickied under general information...

basically as ron just said, except for plant growth, you do need a certain mass of fish to water volume - not that will be a problem for you i dont think.
for eg. a single 1kg fish in a 15000L+ pool wont ever get a plant to grow, but 20 1kg fish probably would.

Well one fish would take a realllly loooong time to get it there. PLJ is one of the few people that experience not enough fish for water volume.

Yeah. That was going to be one my questions. I've seen the "match your grow beds to your tank" ratio, but that's assuming you have the fish mass appropriate for your tank size.

I can't keep up with 500 gallons of grow beds. Thats a lot of cucumbers. Haha.

So under stock the pond but monitor it carefully to make sure they're not under producing enough ammonia for the plants?

Same here, my system is still 90% aquaculture.

500 gallons goes fast! Especially if you build your beds deep.

Thinking I might start with two cement mixing tubs (http://www.homedepot.com/p/Plasgad-Larg ... /202086174) to "test the waters" so to speak.

I am using the smaller ones in my indoor system. Not very deep. Deep is good.

Well u could try and get as many growbeds as possible, and then sell any spare produce to local customers so u can start expanding more! Remember u can always grow vertically too if u don't have enough space (like peppers and strawberries on trellises, lettuce in pipes with holes in the pipes).

Or trees, natures vertical space masters.

Update: So I filled the pond and let the filters run for a day or so. We thought we had a leak because I topped off the pond and it lost 18 inches overnight. I checked for holes at the low water line and found none. I slowly added water a few inches an hour and it held. I'm suspecting I filled too quickly and kicked off some liner capillary loss. There are several corners with folds I'll have to watch out for.

This weekend, we took my son to get some comets (six) and some mosquitofish (9). He's enjoyed feeding them. They seem happy.

I tested the water and the levels were what I'd expect for a brand new pond. I'll check again this evening. Do I need to check daily (twice daily?) to be able to watch the first nitrogen cycle? I'm creating a spreadsheet on my phone (iphone with Numbers) to capture and plot the curves.

I'd make it a GB.