Aquaponic PH 5.9, Leaves Show K Def

So this guy says that the pH in his aquaponic system stabilized at around 7.0 auto-magically:

[video=youtube;g3gQ_OXREo8]http://www.youtube.com/watch?v=g3gQ_OXREo8[/video]

my small aquaponic system (15gal tank, 5gal bed) seems to be stabilized at 5.8 or 5.9. this is great for the plants, but the fish get all tweaky (darting around really fast) and don't feed when the pH is this low. so I'm constantly adjusting the pH up to 7.0 to keep the fish healthy. a few of the lower leaves on about 10" clones showing brown spots and slightly yellowing, which seems like potassium deficiency.

there are aquarium products that contain potassium, but they are anti-microbial agents that kill all bacteria, even the beneficial ones. This thread on a fish forum says that people put slices of bananas on their grow beds, or feed the fish compost worms that have been munching on bananas and other high potassium fruits and veggies.

does anybody know how to effectively add K without killing the fish or beneficial microbes?

Jeeze man,

I can do both separately but I cant imagine all the headaches that must come doing it all in 1 tank..Sorry I can t help you but I saw your thread and was curious. Good luck

it's a split system. 15gal tank on bottom, 5 gallon bed on top. i have a video, just haven't uploaded it yet.

buried a banana peel in the grow bed, going to see how long it takes to decompose. also ordered some red wigglers for my compost bin. going to throw a few in the grow bed and see if they can survive.

also read that sea shells help buffer the pH.

for veg, nothing beats aqua, in my opinion. it's keeping up with the rate of growth with my aerobox and bubble buckets, but for almost $0/week (fish food is dirt cheap) and no headaches with mixing nutes, topping of res, trying to kill off nasties with h2o2 or bennie tea, etc.

about the throw the switch to 12/12 and swap out the 100watt MH with 150watt HPS. might have to add some fish meal to the bed as well for P or get some carnivorous fish to chomp on the feeder fish!

Just wanted to say rock on Haole420. I created a test aquaponics system in my kitchen bay window before diving into a real grow in my garage with tilapia-but I wanted to mention I got a worm farm after establishing this test system and added about 8 worms to the 2x2 grow bed. I've had one or two pop out into the tank and they seem to really love the fish wastes. I have a lot of aeration going on in both the fish tank and the grow bed to help the plants and the worms. I feel confident about my bigger build now knowing that the worms work. I've also got a black soldier fly grub colony starting who'll get lots of bananas and what not. They'll make an excellent source of food for my grow. FYI-my kitchen system has balanced out at 8.0 ph after I added a snail to eat the algae (I currently have 6 goldfish living in there as well). It was balancing out at 8.1 or so but was only about 8-10 weeks old and I figured it would settle a little more per the internet feedback I've seen. Aquaponics rule. Can't wait to make my medicine with it. I'm a Lyme Disease sufferer.