Backyard Aquaponics
A place to discuss aquaponics

Hi Dan
I use it for the gecko`s so you should find it at any store that caters for reptiles.

Some plants will store nitrate even if they can`t use it at the time due to environmental issues (cool temps, low light etc) so it might be worthwhile growing some of those over the winter period to sump more nitrate.

Here`s a snippet of gathered info..
Some plants are more likely to accumulate nitrate that others. Crops capable of high levels of nitrate accumulation under adverse conditions include corn, small grains, sudangrass, and sorghum.
Weeds capable of nitrate accumulation include pigweed, lambsquarter, sunflower, bindweed and many others.
Vegetables capable of accumulating large amounts of nitrate that are most frequently grazed include sugar beets, lettuce, cabbage, potatoes and carrots.

Does anyone know what is the duckweed nitrate uptake?
I do it in my fishtanks to reduce the water changes and they are under neon fluo tubes, they need less light than a lot of other plants and don't need a deep culture bed. Once dried, it takes no room at all.
Maybe that you could freeze it as a fish food.

Duckweed as I recall, has some of the highest uptake of nitrogen along with being one of the fastest (if not THE fastest) growing plant around.

It's been a part of my plan for my eventual "big" system all along. Tilapia supposedly love the stuff, it grows like mad and pulls out whatever nitrates might be left over from the terrestrial vegetation.

Duckweed is awsome! A perfect fish food. I had a hard time finding it. I managed to get some in a wetland that was being bulldozed. However, I was not able to keep it alive so I have to find more this spring; hope I can.

Duckweed also prefers direct uptake of ammonia.

Elodea is also supposed to be a nitrogen sponge. I might even consider a tank for wetland/pond growing Elodea and duckweed and others just to remove nitrates if my grow beds can not handle it or as a back up for when I harvest veggies.

We can do an exchange, duckweed versus eggs
Be carefull of doing the first generation in an extra tank just in case.
It usually grows in high nutrient water bodies, and they are the most often highly polluted by pesticides and herbicides. I did them on aside and took only a few new ones to start the proper culture.
I have tons of it in my fish tanks, and throw 3/4 of the surface of each tank every month in my dirt plant pots.
It is a good fertiliser and a good water purifier, but i found that it can consume trace elements and iron at fast rate which can get you in trouble for the fish health at a longer term.
There is a thread on duckweed here but i'm not sure.

I know that at the aquatic pond/plant/fish place we would go to up in Michigan for stuff for the ornamental pond we built up there, they would happily give up bag fulls of duck weed just for the asking as they usually had to control it in their show and "kennel" ponds/tanks. (part of their business was over wintering koi and other fish for the seasonal residents up there.) I seem to recall another handy floating plant for nutrient uptake was water hyasinth (sp) but of course I can't have it down here as it is a major crime to do anything other than destroy the stuff on site here in FL.

I'm quite eager to hear the results of the DIY sand filter/bed trials.

Oh, and the heating issue. I do hope you look into some solar heating options as it could be quite efficient even in winter so long as you have a sunny patch for a panel and an old water heater tank.

Good luck!

I don't know if anyone else was looking for this, but it'll help me a lot:

http://www.truetex.com/bulkhead.htm

Instructions for a DIY bulkhead fitting. I've had a terrible time finding them, and they are so useful for our applications! The next application of which will be a FBF

That is pretty much what I do for bulk head fittings, but I have a hard time finding the rubber rings. Mathew on this forum was looking to go in and buy a bulk order of UniSeal fittings which I am thinking I can use those with less expense and hassle.

Thanks for the info tamo.

I tried building a FB Filter in a 2-liter Coke bottle today. Things I learned:

- The container needs to be taller or the sand quantity smaller. I think 8oz is enough for a Coke bottle.
- You need very fine sand with the gravel sifted out. Otherwise the gravel settles to the bottom and stays there, inhibiting free movement of the sand.
- If you turn the pump off, the sand will back-siphon into it. That jams the pump. Then you have to take it apart while saying many un-ladylike words.
- A length of bamboo is handy to make the water flow all the way to the bottom of the Coke bottle.
- They look really cool when running. Sometimes like a dust storm (oops), and sometime like something is alive under the sand.
- You can find FB filters on eBay.

FSB filters are hard to start when the turn off often requiring a good push to get going because the sand run down the tube. Thats why I an trying to make on that has very little room for the sand to run down and also a transport tube to keep the path to the top clear. So the sand is blown up through the tube and then settles down and like an hour glas slides into a small gap to be blown back up into the water. This way is easy to start every time.

Most designs I've seen use a check valve on the input to prevent the back-siphon.

My half-assed experimental FSB was too leaky today. I guess I'll have to actually seal it up with silicone, and try again later.

One concern about Reptile calci-sand. If it dissolves to buffer the pH then I could loose bio media which is a problem considering that FSB filters require longer to cycle up.

I noticed commercial FSB bio-filters say they will remove .8 grams of ammonia removed per pound of media per day.

Using that sand that means 46.25 pounds of sand to remove my ammonia and turn it into nitrates. The only thing more amazing that that is the fact that they charge over $600 for a tube and a bag of sand!

Here is a home made FSB. From http://www.cichlid-forum.com/articles/diy_fbf.php
I was thinking more of an pyramid.


As a caution it is noted that the FSB can be made to support both aerobic bacteria and anaerobic bacteria..


Clearly to much sand and the bacteria can consume all the dissolved oxygen.. Hmmm

To give you an idea of what FSB can do here is a picture of two mass produced FSB with the bio filter capacity of 464.5 square meters each.