I purchased the book "How To Do Aquaponics The Easy Way!" from Friendly Aquaponics and put my first Tilapia in the system 12/24/14. It is a 12 square foot floating raft system powered by a 45 gallon tank with 13 tilapia and seems to be doing very well so far as you can see in the attached photo. I have been harvesting lettuce like crazy and I have tomatoes that have flowered and some have begun growing the first fruits.
The challenge I am running into is with fish solids. There isn't much information in the book on how to handle that. The book pretty much gives the impression that the system will take care of itself with no added filtration of any sort. During the cycling process keeping up with water changes to combat the high levels of ammonia almost made me quit. As it stands today there is little to no ammonia or nitrites, and my plants seem to be sucking up the nitrates as fast as the bacteria converts it.
Along the way I added an external canister filter from Cascade to help me keep up with the water conditions. I am curious to know how other people are handling an indoor DWC system. I considered trying to make a swirl filter but I don't think I have room in my living room. My tank water is pretty murky and I am worried about my fish. Although all the readings are spot on and PH is kept between 6.2 and 7.2 my fish don't seem happy over the past few days. They aren't eating well and don't get nearly as excited to see me like they use to. I do appear to have 2 males which are trying reproduce and are constantly aggressive towards most every other fish. I'm not sure if their aggression is making the others behave differently now?
I guess my main question is am I harming my system (taking away too many nutrients) using an external filter? And my secondary question is having to do with their sudden seemingly disinterest in food.
Appreciate any feedback.
1st thought is floating raft system def will not "filter" solids like a media bed system. so your external filter IS needed. You have great pH and chem levels -- My suggestion would be to look at an in line swirl filter and/or a biofilter tank. with your system being so small they may be overkill. The filter you have now may suffice. Spring is in the air and the fish may eat less due to the stress of being chased.
Thanks for the suggestions Brent. I will look into an in line swirl filter and or a biofilter tank. You just gave me an idea although I'm unsure about it at the moment. I purchased the Secrets of Aquaponics DVD and they had this really slow moving tank with several thick Malta media filters. And they aerated the solids as they entered the tank to help break them down into minerals easier. Currently my Aquarium sits higher than my floating raft grow beds and overflows down into them. The water is returned to the aquarium by a small submersible pump. The thought I just had was to overflow into a 15 gallon aquarium I have which I could stuff full of the Malta filters and put some good aeration in there. I might also have the option to put a UV hood on it as well. But then I would have to use a larger pump to push up to the grow bed and the smaller pump would return it to the aquarium. That part scares me a little because I don't know how to size a pump and I fear I would end up flooding at some point in the system.
And I hope it is simply something like spring is in the air because they don't seem interested in eating at all today.
I get the concern abut a flood. My system has a float switch that will shut the pump off if the level changes past a certain point. If the fish visually look healthy and arent acting strange- wiggling, swimming on their side kinds of things - they should be ok. How are your other water readings?
Your malta filter idea sounds like a good option.
I just went and took fresh readings. And I have determined that the pH test from API is faulty. It consistently reads pH at 7.6 while my digital pH has been reading it much lower. I have been trusting the API kit over digital. Today I grabbed some easy test strips and they read pH at about 6.3 and my digital meter also reads 6.3. So I'm going to slowly raise the pH back up to about 7. Everything else looked great to me.
Ammonia = 0 PPM
NO2 = 0 PPM
NO3 = 0-5 PPM
KH = 7
GH = 4.5 - 5
a swirl tank will take care of that
where did you get the book from ? can you send me the author, date of publish and the ISBN number? my local library will order it for me if they can find it.....need the title as well.
Hi Zach - thanks for the feedback. Do you know if I can make a swirl filter easily enough or purchase one? I'm dealing with limited space at the moment in my living room but I am still looking for options.
I purchased the book from Friendly Aquaponics out of Hawaii. The link can be found here.