View Full Version : Pond/fish question

Aug. 11, 2011, 05:45 PM
Posting this in the hopes that there are COTHers with ponds out there!

I'm building a pond in my backyard; it's a fairly small one, maybe 3.5' x 3', about 18" deep. It's all dug and lined and filled now, with a layer of small rocks in the bottom; tomorrow I'm plugging in the pump, running the tubing to the waterfall I built, and then I just have to finish putting in the rocks around it and through the waterfall.

Yesterday I bought some plants for it--a hardy lily, some water mint, and the floaty clumpy seaweed things that you need for goldfish. I'd like to put my goldfish in it as soon as the rocks are done. However, I was an idiot--I potted the water lily in the basket with potting soil, forgetting that duh, potting soil mostly floats...

So I spent today scraping clumps of floating potting soil out with a net, but it still obviously has some in there. Does anyone know if the potting soil is going to be bad news for the fish? I'm guessing there are probably fertilizers and stuff in there--it's Miracle Grow. Do I need to drain and refill the darn pond before I put fish in, or should it be okay after a week or so?

Aug. 11, 2011, 10:34 PM
Dig it deeper first!!
You need at least 3' to keep it from freezing, unless you want to bring your fishies in over the winter.

The soil isn't going to hurt it at all, the fertilizer WILL, as will any pesticides that were in those plants.

I would worry more about the chlorine from the water too, you need to leave the pond with out fish for a week for it to evaporate on it's own or get some de-chlorinator from any pet store/big box store.

Aug. 12, 2011, 08:22 AM
I probably wouldn't drain and re-fill, perhaps just put a hose in there and let it overflow for a while and then let it settle out, unless it's easy to drain (could it be? Mine would be a PITA to 'drain') Also what Nes said about chlorine, if you have city water you definitely have to wait until the chlorine evaporates. As far as the depth, you don't have to bring the fish in if you get a de-icer. You're a bit further north than me, but it seems that we only get about 5" of ice on top of ours so the fish can have the lower part of the pond. I have a floating de-icer (Tractor Supply) that keeps a hole in the top of the ice for gas exchange. In two winters with the de-icer I've only lost one fishie. The first year I hate to say how many we lost, but more survived than died even without the de-icer.

Also, I think it helps that we have two boards that are on top of rocks (with plants and rocks on top of the boards... you don't really see the boards) and it creates two 'caves' for the fish. It's hard to tell where they go in the winter but I'm pretty sure it stays unfrozen in their 'caves'. Sometimes when there is a foot of snow on the pond, I can look through the hole the de-icer leaves (which looks like a tunnel, with the snow plus the ice!) and the fish are just hovering around. Their metabolism is so slow in the winter they don't need to be fed.

Make sure that the fish get adjusted to the water temp gradually, if it's different than what they're used to.

Have fun with it! My little pond is now home to newts and frogs as well as serving as a drinking hole for the chipmunks and birds.

Aug. 12, 2011, 11:32 AM
Well, the pond isn't actually filled with tap water--I lined it and was going to install the rocks the next day, but then we got a massive rainstorm that night, so... well... it filled. d;

I could probably drain at least part of it easily if I just run the pump and attach the tubing, and run the tubing out of the pond...

The folks at the pond store said that if I run the pump in the winter, it will keep the water from freezing... I will look at the de-icer option, though. I'm not opposed to bringing the fish inside for the winter; there's only 3 of them, and they've been living inside for four years now, ever since a friend dumped them on me. They are some hardy li'l goldfish. (:

Aug. 12, 2011, 11:53 AM
And, IMO, 18" is not deep enough to protect your fish from predators... herons, raccoons, etc...

Either much deeper like the 3' suggestion or you are going to have to cover with with some type of protective netting and hope the 'coons don't break in.

Aug. 12, 2011, 03:57 PM
From what I've been told, yes running a pump to keep the water moving will keep it from freezing (to a point) but the temperature of the water can then be below the freezing point. So, it might be 25 degrees and just not ice. The fish will still not like 25 degrees too much, although you'll allow for gas exchange. That's why I went with the de-icer idea, recommended by a friend who had huge koi in a VERY shallow little pond in her yard.

Hmmmm.... Where's my white - I have not had any predator issues (that I've noticed, but rarely do I inventory my 30+ goldfish) and hadn't really thought about that. But a net over the pond will also help keep out leaves!

Aug. 12, 2011, 04:01 PM
I'm right in the city, and we're pretty lucky in that there aren't really many predators--plus my yard has a tall solid privacy fence, so that keeps out just about everything except squirrels. (; I worry a little about herons, but I rather doubt one would venture that far into the city enough to notice my tiny wee pond... we do have a lot of crows, but I'm not sure if they eat fish...

Aug. 12, 2011, 04:16 PM
Crows will eat anything - and Fish Crows have been extending their range - not sure if they are up by you yet.

If you can, set a large, flat rock as an over hang. The fish will appreciate the cover from predators and sun.

Aug. 12, 2011, 06:04 PM
18 inches is too shallow - too cold in the winter, too hot in the summer for fish to really thrive, but if you're OK with some losses or less than thriving fish, then you're good & your fish will still be happier than in many tanks.
Gold fish are better designed to deal with too cold than too hot (oxygen levels in water drops dramatically as temp rises & as round fish, gold fish need rather more dissolved oxygen per litre than those skinny tropicals) - so keep a nice pump or waterfall going on the pond to optimize oxygen levels.
On very hot days, float tap water filled, pre-frozen 2 litre pop bottles in your pond to help combat temp rise.

If your gold fish are "fancy" they will likely put on some growth in the pond but not enough that they won't fit back into their tank for the winter BUT as they increase slightly in girth, their respiration etc needs increase significantly so if you have them in a 20gal tank, you may want to upgrade to a 40gal tank etc (OK I'm a fishhead on hiatus & cringe at the way that many fish are kept in tanks that are way too small soo I'll just state that every fancy goldfish deserves it's very own 20gal of water ie 3 fancy goldfish should ideally get a 60gal tank, though a 3-4 foot tank that is ~40 gal would serve without too much compromise in quality of life - they just need to be fish that like each other).

Check your local water supplier - if chloramines are used in your tap water, then you need specialized tap water conditioners such as Seachem Prime (good value for the money as it's more concentrated than most conditioners) which will bind & immobilize the "amine" part of the chemical.
Of course gold fish are notoriously tough so they will survive both chlorine & chloramine posioning at levels that would annihilate those sissy tropicals.

Run some charcoal/carbon/purigen etc in your filter & that will help remove any stuff that seeps out of the pond plant soil BUT properly done up pond plants should be potted with fish in mind ...

If you're rather attached to your gold fish, pick up a shop fancy gold fish & toss it in the pond for 3 days first (it gets to the pond canary) - be sure to choose one that is nice & lively (ie healthy) so that you don't also introduce disease (never use feeder goldfish unless you're running your own Survivor contest). Any new (shop) fish will always have a higher parasite & nasties count than your home fish, but the volume of the pond should mitigate disease transfer (except with feeder fish which have some amazing bizarre viruses & bacteria).

hmmm how to make this horse related ...
1) do you keep a pony or mini in your back yard too?
2) did you know that you can use "manure tea" to mess with the algae/bacteriawannabeinvaders to your pond?


Sep. 1, 2011, 05:56 PM
Deeper is better but as for the plants once the green algae starts to grow and the pond starts to act like a pond should just rise off the dirt off the roots and let the plant do it's thing, it will get the nutrients from the water directly no need for soil I have found.

( EDIT) Here is a top of the line fish forum Koi-bito.com they take their fish 'seriously'. It is pretty much the COTH of the fish world, A spinoff from a respected magazine dedicated to show quality livestock.

BTW- The hysterical "Forget the Goldfish!!!" thread is gone if anyone has archived a copy could you PM me?

Sep. 1, 2011, 06:56 PM
Green algea in that shallow/small a pond would kill your fish in no time with out the pump. It creates oxygen during the day, then turn around & sucks it up at night; strangling your fish.

Make sure you've got shade over the pond for the hottest parts of the day. Adding in some rocks at the bottom to create little caves will make the fish happy.

Lots of people bring their goldfish in for the winter! For 3 I would go w a 50 gallon with a good filter (you can get lots of gently used fish stuff online) minimum. Goldfish create more poo then most tropicals.

Sep. 1, 2011, 10:19 PM
I leave the goldfish in my fishpond all winter. DO NOT feed them once temps drop to about 50F in the water. Their digestive systems shut down in cold water, so any food is contained in the stomach and will eat thru their side to kill them. Amazingly, they can easily go all winter with no food provided, stay busy and active. I start feeding again when water temp gets up over 65F, and they will "bite" at the food. And even letting fish go longer before feeding doesn't seem to bother them, they do fine nibbling stuff in the pond.

I was told to add rocks at the pond bottom, which provides more surface for things to grow on, helpful in "balancing your pond. White rocks are best, they seem to reflect the sun, water doesn't get as hot in the sun. Also easier to see your fish! I got a couple bags of the white marble at the garden shop, but try to rinse them first, you get a lot of dust in the water. Does settle quick, but not so good for the fish. I put the rocks in way before the fish go in.

I purchased one of the big Rubbermaid tubs that holds 300 gallons, just sunk it in the ground for my fishpond. It is deep enough to keep the raccoons from finding the fish, too small for the big fishing birds with trees overhead. I put some metal plant stands (18" tall) to hold up my water lily basket, Miniature cattails, which gives fish some shade too. I was told to use the cheapy clay kitty litter for potting up the water lily, doesn't float too much if you soak it well before putting it in the pond. I got a miniature lily, and it seems a good size for such a small pond.

I keep the pond full to the brim, so the darn dogs don't have to lean over to drink. They have TWO buckets with fresh water to drink, want pond water! Also easy for a small STUPID dog to get out of pond with high water level. Stupid swimming dogs will make a mess of your pond plant baskets by knocking them over. Pond area is fenced with 3ft decorative fence, but dogs have gotten around it by jumping over, bending the wires down. DO NOT leave a puppy by your pond unattended!! They WILL jump in and can't get out. Almost lost the tiny Corgi puppy that way. If you can't be there, lock any puppy up.

I cover my pond for fall and winter with plastic bird netting for fruit trees. Cheap and comes in big sizes. Keeps the tons of leaves out and dogs can't get in either. I run my pump with a bubbler all winter, which does a fair job keeping a hole in the ice. LOTS cheaper than a water tank heater. However if temps drop below 10F for more than 2 days, ice will freeze solid anyway. So then I run the tank heater for about 12 hours, frees up the pond and removes all ice for quite a while. I think I ran the tank heater about 36 hours over the WHOLE winter last year. BIG savings!!

My pond has depth to the water, almost 30 inches, which is helpful to keep pond less icy longer, protects the fish better. 18" deep is really not deep enough for summer or winter. Some short pieces of 4" or 6" diameter PVC pipe makes good hiding/shade spots for the fish on the pond bottom.

I enjoy my pond a lot, have built a small waterfall, patio, with a garden around one side. I love hearing the water splashing, sitting by the pond is very relaxing while reading or napping.

Sep. 1, 2011, 10:41 PM
If you have a depth of more then about 5' freezing does not matter, the fish will survive anyway.

Sep. 2, 2011, 07:45 AM
I have 3 goldfish in a 44gal aluminum stock tank in my back yard.
They range from a whopping 9" to about 6". The largest was a fancy $3 purchase - probably 3", the oldest is a 4yo 25cent feeder now about 6-7" & the newbie was minnow-size about 2 years ago.

I was bringing #s 1 & 2 indoors to a 30gal aquarium every Fall, but when I was given #3 that stopped.

They spent last winter in the stock tank with a pump & floating de-icer. After the (cheapo) pump burned out sometime in January, the de-icer kept them alive for the rest of the winter.

I stopped feeding when temps went below 40F and don't feed much when I do now - just a sprinkle of flakes.

I have a potted lily-like plant and a floating bloody dock plant plus some floating azola that they are eating as fast as I transfer clumps from the planter next to the tank.
I lined the bottom of the tank with river rock and put in some larger cement blocks & bricks that form caves.
A new cheap pump is keeping the tank aereated.

So far - knock wood - no problem with coons "fishing" & just a couple of sparrows have managed to drown themselves X P

Sep. 2, 2011, 03:01 PM
Deep is better has to be below the feeze line and then add...I've had Koi ponds for over 10 years now on my 3rd one and its a wopper over 4 ft deep and 12 feet long 8 feet wide haas an upper pond the cascades into it where the plant live...we just fill w/ well water and have 3 filters since its like 30,000 gallons or some bizarre amount.
You can empty by hooking up the filter pump and let it run on the lawn...yes the fertilizer will kill your fish.

Aeration is very important and remember its pond not an aquarium so don't go nuts trying to keep it crystal clear...but do have a UV light in line or in the Bio-Filter tank..

Sep. 2, 2011, 06:00 PM
I have a 3 foot diameter pond that is about 16 inches deep. I also live in a very mild climate,in the PNW, but we do get about 2 weeks of snow every winter. My electric pump did not keep the pond free of ice, but it did make a spectacular ice sculpture of a frozen water cascade in its efforts to keep the water moving. The pond froze to a depth of about 3 inches before the water warmed up again and the fish were fine.

I have 3 fish, all former 25 cent feeders. One is about 9 inches and is at least 6 years old. The others are 4-5 inches and are from last year and the year before.

I pot my water lilies in a basket with rocks.They do not need "soil" but will absorb the nutrients that the fish poop out.

My pond is entirely in shade/filtered sunlight so algae and overheating are not too big a problem. However, since it is only about 50 gallons, I do a water exchange of about 10 gallons per week if there has been no rain.