Nitrate removal for my basement pond for winter

[bgarthe]

I’m a nut who brings my koi inside for the winter. My 3,500 gallon outside pond is four ft deep in the middle and no shallower than 30” on the edges, but I don’t trust things when it comes to winter. So….I bring them in. I still have to watch the nitrate levels even when the basement temp/water temp is in the 50s. At the moment, it’s -5 outside. Here is my floating algae scrubber. The Coolwhip container has several handfuls of algae in it and I have to empty the scrubber weekly. My bioload is too heavy for the fish to make it outside in the winter even with a heat ring.


Here is the general set up.

 

[86 ssinit]

Nice setup! Lucky koi! Is this your first time bring them in?

 

[bgarthe]

No. I’ve been bringing them in since the eighties. With my getting older, I have alter my methods a bit so as to minimize lifting buckets in and out.

 

[coralbandit]

Read up on potassium permanganate.
Potassium Permanganate
Taken from; Potassium permanganate | The Skeptical Aquarist

NICE!!!

 

[bgarthe]

coralbandi, thanks, but I’ve read up on it through the years and have elected to go other routes. For koi, I simply use a 40w and 25w UV bulb to keep the water clear outside. I use a 9w bulb for the indoor one even though algae is not a problem. My PH ( for use w PP) is on the high side as well.

 

[DaniosForever]

If only I had a pond that big

 

[BPSabelhaus]

Why not grow some veggies? Tuscan kale, taro and strawberries have all done well for me.

 

[86 ssinit]

Strawberries! Has anyone tried strawberries on the top of a fish tank? Sound tempting!

 

[RayClem]

There are a number of "tank topper" plants. These are margin plants that live around the edge of ponds and streams. They can tolerate their roots being in water with their stems and leaves being above water. Since the leaves are above water, they are exposed to light and can readily absorb CO2. They will absorb nitrogen compounds such as nitrates from the water to fuel their growth.

There are a number of household plants that make good tank toppers. However, you can also find vegetables that grow well in hydroponic environments that would be ideal for nitrate removal. Although I have not tried it, I understand sweet potatoes are ideal for nitrate removal. Just make sure at least 1/3 of the sweet potato root tuber is above the water level so shoots will generate.

 

[SparkyJones]

Yes. There is that. Aquaponics type grow bed to work as a nitrate scrubber.
Not extremely complicated fairly clean also for indoor work, but indoor you'd need to up the lighting game for the plants.

Then you have it on a valve to flood the bed every so often and can be automated to flood and recede and you can grow just about anything like that.

I'm assuming you want to get around water changing to reduce nitrates, and looking for another way, turning the basement into a winter garden room would fit the bill, herbs, veggies, fruits, could all be grown off the nitrates and waste from the fish.


You could also just go with water lily's and get the top of the indoor pond mostly covered. That should help with lowering algae production as the surface gets mostly covered and help with nitrate removal of you didn't want to go the aquaponic route.

Have you tried pond matrix?

 

[BPSabelhaus]

Strawberries! Has anyone tried strawberries on the top of a fish tank? Sound tempting!

That was last years winter project. Only issue I had was unrelated to it being aquaponics. After a few months I started getting mites. Ended up having to just toss a couple trays of plants to stop the spread. I grew Ozettes from root stock and runners as well as European yellow strawberries from seed which was fun. Those I harvested a few berries from before moving them outside which was a surprise. I had hoped to just grow the plants

With the mite issues I stopped growing strawberries indoors. I have kale growing in one of my Endler tanks now. Last year I had issues with white spot fungus, but moving the lights higher seems to have resolved that.

 

[JustAFishServant]

RayClem is right; apparently, sweet potato can work well. However, it's sometimes known to rot.

Some plants do well straight into the water or in the filter media. Some plants need a bit of dirt or clay, gravel, or other growing mediums.

For plants with their rooys planted straight into the tank, I've had great success with monstera, pothos, philodendron, chinese evergreen, basil, mint, strawberries, aluminum plant, english ivy, and many more!

For plants requiring growing medium, I have very good success with grape leaf ivy. It's thriving in sponge filter media in a goldfish tank. Probably my most successful plant yet! Purple waffle is a great plant too, although it won't thrive without a growing medium (sponge, gravel, leca, etc.)

I've also grown many others but I can't think of them right now (Christmas brain lol.) I'll update as I remember

 

[BPSabelhaus]

I have yet to have success with sweet potatoes.

Just in general lol never get em’ to root no matter the method. I want to grow them for the vines.

 

[BLJ]

I’m a nut who brings my koi inside for the winter. My 3,500 gallon outside pond is four ft deep in the middle and no shallower than 30” on the edges, but I don’t trust things when it comes to winter. So….I bring them in. I still have to watch the nitrate levels even when the basement temp/water temp is in the 50s. At the moment, it’s -5 outside. Here is my floating algae scrubber. The Coolwhip container has several handfuls of algae in it and I have to empty the scrubber weekly. My bioload is too heavy for the fish to make it outside in the winter even with a heat ring.
View attachment 868666

Here is the general set up.
View attachment 868673
View attachment 868674

I have left mine in my 1000 gallon pond all winter and never lost any except 2 years ago before the freeze mink took 3 hours to empty my 12 20 year old koi I caught it on security camera. Now an electric fence for the winter here in Wisconsin

 

[BPSabelhaus]

I have yet to have success with sweet potatoes.

Just in general lol never get em’ to root no matter the method. I want to grow them for the vines.

I stand corrected lol warm and humid guppy power!