Fish population sustainability with natural filtration in a watercourse

[urglik]

i've recently developed a watercourse and rescued some goldfish (8) which i added to the pond in the course, now the pond also has around 50 young fish about 2". i guess they do that.

the watercourse has a fair bit of pea gravel in it at the moment and some rocks. if the pea gravel is not braced with larger rocks, the water flow of about 10 gallons a minute washes it down the way. at the moment it's concentrated in two areas and much of the 100 foot long course still needs to be filled with more rocks. more pea gravel may not be needed.

one area of concentration at the moment is the round water kiva (7' x 5") with 3-4 inches of pea gravel except for under the fall that feeds it where there is about 8" of gravel that spreads out. another 25 feet of the course varies between 2-3 inches of gravel.

the only active filtration i have at the moment is a plastic box in the pond that holds maybe a gallon and half with a small pump with an inch of sponge around it placed near the surface. looks like a little fountain.

just cleaned it today after about 10 days. 10 days because i pretty much new what i would find...not much to clean and the water throughout the course is clear.

i did an ammonia test which was negative. not definitive i would imagine. ph is like 7.8. the pond is filled from our well. hard water with a high ph. i have a little bit of an algae issue.

i'm using a barley straw and peat concentrate to try to keep it at bay. not too impressed, but there has been a fair amount of water exchange the last few weeks due to turning the course off at night when temps drop below 60 and the pond floods.

so the natural filtration at this point is pretty good even though a lot more rock is needed to fill the course, cover the rubber, etc.

i do plan on building a filter. maybe a BIG one...lol

the baby fish are a huge concern for me. the pond may hold 2000 gallons when finished soon (currently 500 gallons) and the watercourse holds maybe another 500. my first impression is that the system cannot support so many individuals.also, i currently have no natural predators for eggs and fry. i don't kill animals. it's bit of a sticky-wicket.

i'm wondering if i could navigate through this situation with a lot of natural filtration, an added filter, and natural predators and see if everything might balance out.

winter is around the corner and the whole timing thing of turning off the course and settling the pond in for winter is something i never have done. i would think an added filter could be very important after i turn off the course.

so anyways, natural filtration seems to rock...

 

[Meyer Jordan]

Photos of your current set-up would help immensely.

 

[urglik]

Photos of your current set-up would help immensely.

thank you for your interest. here is video i posted in another section. please excuse the music. this was for my facebook friends.
https://www.gardenpondforum.com/threads/i-started-out-as-a-child.20136/

 

[budgenator]

For now, the water courses pea gravel should provide enough biological surface to keep ammonia under control, but algea usually means your nitrates are creeping up. After watching your video, I'd guess that if you plunked about $10.00 of watercrest in the gravel on the water course, the algea would only be a fleeting annoyance in the spring and the goats would love it.

Your goldfish are going to keep breading, untill they find the natural balance point. I started with 2 dozen feeders and they've grown to over 200 over the years. I lose a few senescent adults over the winter, gain a hundred fry in the spring, but somehow it all balances out.

Rocks on the water course are great and very attractive, rock on the pond bottom is just a trap for all manners of toxic gunk, so don't do it.

Get a stock tank heater to keep a hole open in the pond over the winter and keep the fallen leaves out of the water and you should over-winter fine.
There's a whole forum topic on winterization to browse.

 

[Meyer Jordan]

thank you for your interest. here is video i posted in another section. please excuse the music. this was for my facebook friends.
https://www.gardenpondforum.com/threads/i-started-out-as-a-child.20136/

You may want to switch from pea gravel to small cobbles that will withstand the water velocity.

 

[sissy]

liquid barley with peat in it is much better

 

[urglik]

For now, the water courses pea gravel should provide enough biological surface to keep ammonia under control, but algea usually means your nitrates are creeping up. After watching your video, I'd guess that if you plunked about $10.00 of watercrest in the gravel on the water course, the algea would only be a fleeting annoyance in the spring and the goats would love it.

Your goldfish are going to keep breading, untill they find the natural balance point. I started with 2 dozen feeders and they've grown to over 200 over the years. I lose a few senescent adults over the winter, gain a hundred fry in the spring, but somehow it all balances out.

Rocks on the water course are great and very attractive, rock on the pond bottom is just a trap for all manners of toxic gunk, so don't do it.

Get a stock tank heater to keep a hole open in the pond over the winter and keep the fallen leaves out of the water and you should over-winter fine.
There's a whole forum topic on winterization to browse.

thank you. i do need to upgrade my water testing abilities.

i love the watercress idea, if i can get them established before you know who finds
out. the goats are not too keen on moving water so perhaps they will not notice it.

for the bottom of the pond you would suggest leaving it bare in general?
i would like to provide a protective structure for the fish to escape predators such as raccoons and cranes. there was even a snake in the pond this year, but no coons or birds. i have considered a tower of 4-5 wood pallets with each pallet being weighted with rocks.

i've had a nice long roll of netting for a few years. now i know why...

depending on my needs, a stock tank heater may exceed my budget for electrical costs. i've looked briefly and i thought i would need
one of 1000 watts or more which i cannot afford to run.

 

[budgenator]

for the bottom of the pond you would suggest leaving it bare in general?
i would like to provide a protective structure for the fish to escape predators such as raccoons and cranes. there was even a snake in the pond this year, but no coons or birds. i have considered a tower of 4-5 wood pallets with each pallet being weighted with rocks.

i've had a nice long roll of netting for a few years. now i know why...

depending on my needs, a stock tank heater may exceed my budget for electrical costs. i've looked briefly and i thought i would need
one of 1000 watts or more which i cannot afford to run.

Maybe a tile chimney liner or 2 to give them some hidey-holes and netting often work to discourage all but the most persistent of predators. but mostly bare so it's easy to clean. I had rocked my pond, but removed them searching for a leak, the amount of much that accumulates between the rocks on the bottom is horrifying, and it's all giving off toxic gasses down at the bottom where the fish are in the warmer water at the bottom.
Looking at the size of your pond you might get away with something a bit smaller than the typical 1250-1500 watt heater, TSC has a 250 watt deicer
http://www.tractorsupply.com/tsc/product/farm-innovators-multi-use-utility-deicer-250-watt
it might be enough, although you look a little on the shallow side, neither of us has the advantage of the old "10 degrees water by the water", so you might consider that your not paying for electricity to run the watercourse pumps during the winter in your budget too. An aerator might be a good idea for the winter too, especially if your going with a smaller de-icer. there are a lot of de-icers specially built for ponds all over the internet, so take a peak at Amazon and the rest too.