Backyard Aquaponics
A place to discuss aquaponics

Hey Contiuum, chlorine will kill bacteria, but chloride ions are the same as what you get when you add salt (sodium chloride) to your system for fish health. Ammonium chloride should be fine.



My understanding (remember I am new to this too!) is that DWC and NFT don't have much biofiltration capacity as it is the bacterial colonies on the media which convert the ammonia to nitrite (nitrosomonas bacteria) and nitrite to nitrate (nitrobacter bacteria). The plants simply take up the nitrate and play little or no role in the biofiltration. It is the ammonia and nitrite that are toxic to fish, especially ammonia at high pHs like you have - there are charts somewhere that show ammonia toxicity with pH and temperature.

My towers are a bit of an unknown quantity as some towers have media which support the bacteria colonies, and others are similar to NFT with no media and little biofiltration. Mine are filled with bird netting which is getting a good bacterial film on it, so would provide some biofiltration in addition to space for more plants to take up the resulting nitrate.

Have a read through the 'Oft repeated rules of thumb' thread as it has some great information from experienced APers viewtopic.php?f=12&t=6646&hilit=oft+repeated+rules

Was looking at this thread last night on radial flow filters in a 5 gallon bucket as a possible add on to deal with extra flow with my larger pump, and nutrients and fish poop as my trout ramp up their feeding viewtopic.php?f=1&t=23889&hilit=1+or+2+RFF

I was glancing back through and don't see anything about the pattern of flow through the tanks and bed. Does the flow from the fish tank go to the media beds and from the media beds to the DWC or does it go directly to the media beds and the DWC separately? Let us know what you've got

A little back ground. I started as an experiment to see if I can do it because I plan to build a big one as yall know I have running 2 IBC totes 4- 4x4 media table and one 4x8. well I came across I guy that was selling his hydroponic greenhouse and I traded a work truck for another 4 IBC 5-4x8 flood tables 4-4x4 flood tables 6 75 gallon reservoir which Ill use for my media like my other 4 are plus I have 2-2x4 fluoresces that I use for seedlings and I got 15-17 600-1000watt electronic dimmable ballast with lights that I am going to get rid of cuz I don't want to pay for electric bill. I wanted to build a 30*60 green house within a year IF I can figure out I can manage it (my prepping senses going crazy for self-sustaining food supply and I like to peddle veggies. in summer time). anyhow I got them and dream of using most of it.

bear with me ill load a few to show what I got



picture above see the 1" pipe coming from tank to solenoid valve that's run by a repeating timer each media bed floods for 13.5 mins about and unless I redo my stand pipes drains in about 35 mins after that valve it goes to my index valve then to 4 tables... have it like this so my pump can run none stop from my timer that u can see in upper corner from 630 am - 730 pm ... the red ball valve u can see at bottom of pic is my return from sump tank that's on a float switch and u can see one of my ph/temp meter the other is on my flood table and my big bubbler I also have small bubblers on my sump tank and my floating raft that never ever turn off I also have 800gpm pump from IBC pictured to the next to help circulation of heat and everything that always runs as well its connected at bottom valve between tanks



u can see my cheap crude filter I put cuz when I added rocks it still turned cloudy so all 4 tables and flood table runs to 5 gallon bucket with many holes that has half of a new pillow fiber stuffing the 400-800 gpm pump in pic goes to flood table that stays on 24/7 that runs over stand pipe and returns here even in night time and u can see my big pump that has a 1" return back to both fish tanks



my pump is over size so u can see another ball valve I have to every table to make it slowed to fill up and shut off at 13.5 mins at just over stand pipe that's inside my 6" media guard u see there

my aquarium heater I built has water heater element that has water tight cord from bottom up to my plug that I ran to my 8/3 extension cord to a timer that ran 12 hours in night early spring and 24 hours in jan/feb.



u can see my test this morning ammonia was added about 48 hours ago after test I added more



washing rock .. cant take credit for this idea

So if I understand that correctly your fish tank feeds your media beds sequentially and all of these drain to the sump. In the sump you have a pump that pumps to the DWC bed and that's always going. So basically your media beds are providing solids filtration for the DWC along with the bucket that has netting in it.

Absolutely correct

Re: your fish stocking levels - there is some information here - http://www.backyardaquaponics.com/forum/viewtopic.php?f=12&t=6646 keep in mind these are maximum stocking levels if you intend on high stocking levels then good aeration and good solids filtration are a must.

There are other yardsticks for figuring this that I've posted recently (the actual numbers below are probably from the Earthan Group) -