Backyard Aquaponics
A place to discuss aquaponics

Hi,

I thought you might find this article interesting because it seems you could use water flow to both reclaim some of the power you spent pumping your water up, and aerate your water at the same time. Does anyone think this could be useful in aquaponics? Maybe it's required to pump the water up too high, and it doesn't make sense; feedback would be interesting.
http://www.aidg.org/component/option,co ... ,34/p,1136

Also I have a question about plastic, I have a Fluval 405 canister filter and it's black plastic. Does anyone know if this is acceptable to use in a system growing fish intended for human consumption? From reading this site I assume black plastic as a rule of thumb is a no-no; but it seems strange to me that Fluval would make a filter that could be bad for fish.

Thanks,

Humanfly

The pico-electric item looks interesting but way outside my area of expertise. On the plastic, does the container have one of the recycle codes on the bottom and, if so, what number is it. That will often give you a better idea on its usability.

Perhaps such a hydro electric system could be used to say keep a battery backup charged but most people don't usually have that kind of flow running continuous unless they are a huge aquaculture facility.

Now if one's site had a nice mountain stream near bye, that energy of falling water could do alot. Heck, one could probably use the energy of the falling water more directly in a ram pump and skip the electric side of things all together.

As to plastics. The main reason people often avoid black plastic is that it is more likely to have recycled content. That does not mean all black plastic is bad. There are two sides of the issue with plastics. First is what did that recycled barrel of IBC hold before? Is it safe to use for fish/potable water?
Second, and probably more difficult to find answers for, leaching/outgassing of chemicals from plastics that might not be good for us long term.

As to the particular canister filter, I don't know anything about it. Perhaps you could contact the company and see what they say. Then again, in many situations, companies have to give the answer no if it has not be specifically tested and approved for use with fish meant for human consumption. To some extent, people will have to find their own comfort zone. I have a pool sand filter in line with my system, I'm certain that isn't "approved" for use in a food system but we still eat from our system.

Good luck finding your answers.

HF

The Fluvals as well as many other good quality brands make them out of what appears to be acrylic. The colour is put in to stop algae growth. As far as I am aware they are fish safe and human safe (as far as anything is). Used a baby fluval 4 for many years in a small tank. Only thing I'm wondering about is the head on that cannister (pump head hight), not normally designed for lifting water.

Thanks, Sleepe! It's manual indicates it can lift water to a maximum of 4.5 feet. I'm using it as a filter for the aquarium, not a pump for aquaponics at this time, later I'll get a proper pump. I wanted to get an aquarium up and running and get some fingerlings this year, next year I'll build a pond or tank outside and get the aquaponics up and running.

Greetings,

First post here, long time lurker - have absorbed much useful information here, thank you all.

I come from a long aquarium background and can tell you that generally anything used in the fish tank world is potable and hence should be safe to use in a system with produce for human consumption. That does not mean that it would certifiable in a commercial process.

As stated, individual comfort varies, but generally, if anything toxic were to enter the system from equipment, your fish would tell you quite quickly. An aquarium is a TINY volume compared to most systems on here, and with most peoples' water change regiments (or lack thereof), toxins would accumulate quite quickly.

Also, if the equipment was ever used in an aquarium with fish or plants, I would not use it a food growing situation.

I am not making suggestions here however, and you should do what you are comfortable with.

Personally, I would not hesitate to use most new aquarium equipment in a home operation that provides food for personal consumption.

If you are concerned, an external pump plumbed with potable PVC could be an alternative.

All got to be better than the stuff in the river systems and the crap that gets sprayed on the food we get from the supermarket

at 3 bar (30 meters) a pipe of 2" lets pass 750 litres/minute
to produce this flow at this head with a reasonably good pump (60% efficiency) you would need at least 6.25 kW
a result of 60 W from an input of 6.25 kW means an efficiency of less than 1 %

not worth the bother

frank

The only time that i have seen these hydro-electric systems be usefull, is when there is a natural flow of water coming down a hill from a spring or somesuch.