Also, what do I do about raccoons?

I do this sort of thing with my 130-gallon preform pond. Whenever I change some of the water during the growing season, I use it to water the veggie garden. I also grow lots of water hyacinth and water lettuce. These floating plants provide shade and cover for the fish as well as little critters the fish like to eat. They will quickly cover the pond if I let them, so I harvest them regularly for the compost pile. This also helps remove excess nitrogen and other nutrients. Any kind of plants like this will be more pleasant than algae, both for aesthetics and for compost!

Basically, you’ll want to use some kind of biofilter (manufactured or diy) instead of a pool filter. The purpose is not to remove all the particulate matter but to encourage the bacteria that break down nitrogenous waste products. The more toxic ammonia is converted to nitrite to the least toxic nitrate, which will still be in the water and available for your garden plants.

What keeps algae down (but never completely out) is biofiltration, plants, and water changes. New ponds and ponds coming out of winter often go through a temporary algal bloom but then settle down. Barley straw can also help suppress some types of algae.

You can run a fountain as well with just enough screening to keep large objects out of the pump.

The blue dye was probably copper sulfate, which is acutely toxic to plants and mildly toxic to fish. Needles to say that won’t be good for the garden or compost!

Don’t expect a crystal-clear squeaky-clean looking pond. That is not healthy for fish. Think about how many natural ponds are the color of pea soup or coffee and cream, but still harbor lots of fish. If you can be happy with an attractive pond where you can see the slightly fuzzy bottom most of the time, you can strike a healthy balance.

Unless you’ve got sinkholes or major erosion issues, it should be okay to sit on the ground, maybe on a layer of sand. Think about it. A stand will be bearing the same weight (well slightly more) on the same soil. It definitely should be as level as possible. Then when it overflows it will do so evenly around the rim and not pour out on one side. When I know a big storm is coming, I draw the pond down 2 or 3 inches if I have a chance.

Even if you have days over 100 (we have a few of those here in MD too) the temperature of a pond this size will stay close to the day-night average, so you may be okay in the desert, but you might be pushing the comfort zone if you have lots of hot muggy nights too. Goldfish are pretty hardy though, as long as oxygen and ammonia levels are under control.

This is another good reason to have the tank right on the ground, as that will act as a heat sink. In fact, things will be most comfortable and stable if you can sink the tank into the ground, bank soil around the walls, or a combination of the two. Barring that, the wooden structure should help shade the walls and floating plants will shade the water surface. Other shade structures might be in order depending on your situation.

A little ice is okay as long as there is some open water for gas exchange. I just disconnect the waterfall and leave the submerged pump running so there’s always some surface movement. Again, having the pond in the ground helps stabilize and moderate temperature.

I haven’t had a problem with raccoons taking fish. Maybe a frog or two. A heron got a goldfish once. Raccoons are more adept hunting in broad shallow water than in something like a stock tank or small pond, especially if the fish are smart and hunker on the bottom (which they will be if one should get caught). A motion sensor light or barking dog might be enough to remind them that trash cans are much easier pickings! Also, the larger the fish, the more vulnerable it will be to large predators. I assume you won’t be trying to keep large koi in this pond, so I woudn’t be too worried.

I'm planning to build a pond with a Rubbermaid stock tank, which will replace the small lined in-ground pond I built last year. Now that I know what I did wrong the first time, I expect this to work well. This tank is about 2 feet deep. I will dig a hole a little larger than the tank and about a foot deep. I want the tank to be partially below ground for temperature moderation and partially above so I don't get runoff water contaminating the pond (as happens now with my pond). Then I will carefully level the ground on the bottom of my hole. Nothing is more frustrating with a preformed pond than not having the top level. My soil, tamped down well, is pretty stable. If yours isn't, you could pour a level concrete pad under the tank. Then I'll put the tank in and fill soil around it to ground level. The top of the tank will be about a foot above ground level.

The amount of overflow from a tank is not likely to be a nuisance, but I want to control the water that comes out, so I will make some overflow holes near the top of the tank, and run pipes through them so the water will exit through the pipes. You can even attach a hose to an overflow pipe and run the water to the garden.

To make it pretty, I'll get some of those "garden wall blocks" from the home improvement box stores to stack around the outside. Capstones on the top will make the tank completely disappear. I live in FL, where wet wood is a termite treat that won't last out a year, so that's not an option.

If you have fish, you need a filter. There are hundreds of plans on the net for building a DIY biofilter. I just built one using a large (9 gallon) flowerpot which looks nice sitting at the side of the pond. A small pond pump (available at those box stores) pumps the water from the pond into the pot filled with filter media, and the clean water spills back into the pond from a spout at the top of the filter. My filter has a bottom drain to remove any gunk collected in the filter, and this stuff makes my plants love me. My pond is badly overstocked with fish (I'm building bigger!), but with this filter the water is so clear as to be invisible.

You can certainly have a fountain in your pond. There are attachments for the pumps that allow you to run some of the water to your filter and some into a fountain.

Once my pond is complete, I will make a frame of 2x4s that will fit around the outside and fasten pond netting to it top. The netting is practically invisible, so if the frame is painted to match the block wall, this protection won't be ugly. If predators haven't tasted your fish, this will work fine. But if the raccoons your seafood cafe before you cover your pond, you will have to build something a lot stronger.

Ponds need water changes, filters need cleaning, pond bottoms collect gunk that needs to be vacuumed out from time to time. All of these processes yield fertile water that plants love.

I hope this gives you some good ideas.

Don't worry even a filtered pond will have good water for plants and it isn't just algea that is good for plants, it is the fish waste. Plus you might not see algea but it is in the water unless you have a UV light. An easy thing for you to do is either get a filter with a back wash feature and you can pump out the dirty filter water directly on the plants or into a container. Otherwise with a stock tank set up you can rig a hose to the bottom drain along with a valve to open and close the flow. It will suck from the bottom where the dirtiest water is and the hose allows to put it right on the plants.
I'm an avid gardener. String algea is great in compost but I just used dirty water directly on the plants and that was more than enough fertilizer for flowers, veggies and even trees.

I know most of these things, having had a huge pond for 3 or 4 years. The in-ground ponds with the natural look, plants, flagstone edging, it was gorgeous. I do recall the algae on the sides despite the serious filtering. I know the fish poo is great fertilizer in itself.

I put an Anacharis (I believe) plant in it, elevated in a pot out in the center deepest part of the pond. That thing became a monster. I had to use a rake to tear it out so that the fish could still swim in the water! The scum that built up on the bottom became a great new place for it to grow.

It was a major pain to clean the thing though, we had in mind beauty, plenty of space to get creative with, etc. Didn't know enough to plan for the seasonal maintenance though.

The thought of an above ground pool that I could reach every part of to clean was very appealing after dealing with slippery slopes over 4' deep.

The stock tank is only 25" deep, and I believe I can reach the center from either side. I don't want to cause too much work such as digging to partially bury it, was hoping to just sit it on the ground, fill it up, let him build whatever he chose to camouflage it, and later make a waterfall at one end with the aquaculture setup.

He thinks it needs to be supported by wood underneath, that the weight of the water might make it settle unevenly. Don't see why it wouldn't do the same to whatever he built under it though.

I am very mathematically challenged, so need to know the size of pump (gph) to run the biological waterfall filter some day, and use that pump for a fountain until I get around to the rest. I'm so very likely to overstock it with fish, so need good filtration. And will be using it to water a large garden, so there will be frequent partial water changes.

"A filter with a back wash feature" sounds very usefull for my purposes. Any links to a good one online? I have ordered the stock pond already, but am waiting to get good suggestions before treading any farther...

Still trying to decide what fish to have in there. LOVED the koi, but I wouldn't put more than a couple in such a small pond, and I want diversity. That will be the fun part for me, the algae and poo are just for the garden.

Google pressurized pond filters for filters with a backwash and oversize the filter for large fish load. I also like a lot of fish variety. I like shubunkins because they have that calico look and get flowing fins like koi. Also check out wakin. They have that red and white look of kohaku koi and cool tales. Both are very hard and when they mix you should get some cute babies!

Is it possible with a 300 gallon tub to have 2 or 3 koi, and assorted other small fish, and use sponge filters? The filter I linked to says it will work for a 250 gallon tank as a primary filer, but of course, I can have more than one with a gang valve connected to one pump.

Just squeeze the gunk into a bucket and pour on the garden!

Keep in mind, there WILL be water changes, since he will use pond water for watering the garden as well...

I use a product called Prime as a water conditioner.

IF this would work, what size pump (gph) do I need to get?

Here is a link that might be useful: Hydropond IV

Here is one of the best descriptions I have found of how to build a filter. I made a smaller version of this in a large flower pot and it looks and works great.

Here is a link that might be useful: DIY filter

Update: He has decided to build a wooden deck and sit the pond on top of it, and build wooden walls surrounding it. Then later he hopes to build a sloping roof wider than the deck so any run off doesn't get into the pond. Going to have to figure out what types of wood he can get that are fish-safe and not too expensive...

We've gone from full sun, to partial shade, and eventually no full sun, just daylight from around the roof. He is also considering a hinged lid of fencing material for the pond itself to keep any unwanted critters out, that can be opened when sitting by the pond and visiting, etc.

May be a few years before anything happens, lol. I just wanted a quick-and-easy, but it never happens that way, does it.

I ordered a filter with a pump and fountain all-in-one, hope I get to use it some day soon, lol.

A 300 gallon pond should have but ONE Koi in it, Koi get large and experts say you should have 250 gallons per Koi, up to 1,000 gallons.

When getting a filter don't get one "sized" correctly for your pond, as they tend to be very underrated. My 200 gallon pond has a Pondmaster pump/filter combo rated for at least 500 gallons and it is OK, I would not get anything smaller.

As far as rain runoff is concerned, a pond does not add to the water that runs off your yard. In fact, it may lessen it, as before water overflows and runs out of the pond it must first fill it to the very top, and some water will evaporate in between storms (that obviously doesn't run off).

I've had galvanized stock tanks as ponds for years and haven't had to have a wooden foundation or any kind of foundation. I just sit it on the ground. If it's not level, I spread some sand or dirt (dug up from another part of the yard) under it until it is. One time it settled a bit after I had to put a good bit of dirt under it, so I just drained it and put a bit more where needed to level it back up. No biggie. Didn't take long.

Those stock tanks last for years. Since they're designed and manufactured for ranch use, they have to stand up to a long time of weathering and wear. If they didn't, ranchers wouldn't keep buying them. That's why you don't see many ranchers using those rubbermaid tanks ~ they don't hold up nearly as well. I also like the fact that once I scrub a new one out with vinegar and then dish soap to remove any leftover oils or chemicals from the galvanizing process, I don't have to worry about anything off-gassing into the water like I do with plastic or rubber.

I've never tried koi in there as I've always read that it wasn't big enough. Even in the eight foot round one, though I have been tempted in that one since it's almost the thousand gallon recommended minimum size for swimming. What's stopped me is I know if I get koi, once they grow large, I'll either feel guilty every time I look at them in the stock tank or will have to come up with a bigger pond for them to live in. (Hey! Maybe that's a way for me to justify getting the 10' wide stock tank. ;) I've never had a filter on any of them either and haven't had pea soup problems, but I usually go heavy on the plants and light on the fish.

I have these in the pastures and pens for my livestock as well and keep a goldfish or two in them to keep the mosquitoes out. Let me tell you, those goldfish grow HUGE from all the food ~ not only the mosquitoes, but little pieces of grain and alfalfa pellets from the horses' muzzles when they drink. Raccoon treats they are for sure, but the only problem I've had with critters getting in them are squirrels. They try to get a drink from them, then fall in and drown. So the ones I have for my livestock I just float a board in so they can get out. I haven't had that problem at all in the ones I use for ponds near the house. Probably because of all the plants and pots making it easy for them to get out (that or the little heeler dog who thinks it's her job to keep the squirrels in the trees ;).

I think your boyfriend's son is overthinking this. IMHO you should get a tank, bring it home, plunk it down where you want it and set it up. Just do it. It'll be fine.

hi knittlin--just wanted to confirm, raccoons can't climb into a stock tank? How tall are yours? I'd like a pond but need something raccoon-proof! Thanks!

Yes, they certainly can climb into a stock tank and they can also wade right into smaller ponds.

We use chicken wire covers on our small ponds every night or they are in them and we have no fish in these ponds.

{{gwi:190900}}

They are in my whiskey barrel ponds too.

BTW, A 300 gallon pond is too small for Koi. They do not stay small in smaller ponds unless malnourished or otherwise unhealthy though goldfish will. A two foot long fish in a few years is much too big for such a small pond. Most feel 1000 gallons and 3'deep is minimum for optimum koi heath and vigor. Get some nice colorful goldfish and they'll be healthier and happier and they require less filtration.