Backyard Aquaponics
A place to discuss aquaponics

I added about 15 comets to bump up my numbers (replace the few I lost), so think I have about 27 fish in the tank now. Unfortunately, it has resulted in a big ammonia spike. I've changed half the water out, and I'm trying to keep the water in the sun to keep the water temp as high as possible - but winter is on the way and the water temp is fluctuating between about 10 and 20 degrees. Also need to remember to add the salt...

Anyway, the tomato plants have been going crazy. Lots of cherry tomatoes on the way, though I'm not sure they will all ripen before the cold weather really hits. The snow peas also seem to be doing pretty well, but the lone broccoli seedling has been 1cm high for about 3 weeks.

I think I will spend winter figuring out how I can add an NFT extension in time for spring.

Yeah... bit of a spike going on there Owen... see how quickly the ammonia and nitrite drop off... just ease right back on the feed for a day or two...

Pretty colours though.....

Whack some silverbeet in (good time to sew now) - it'll go mad.

looks like your tomatoes are tying to escape from you system owen

I've had a massive crop of cherry tomatoes, but with the cold weather rolling in, the plants are starting to turn brown. I've thrown in some silverbeet and broccoli seedlings, so we'll see how they go. The first snow pea is on the vine, hopefully plenty more to come.

I was home from work today, and decided to add some maxicrop to the tank. When I looked down the standpipe, I noticed there was no water at all in the bottom of the grow bed (not normal in my system, since the last inch of water can't drain away). Sure enough, my borrowed pump has finally expired (sorry Simon!), after many years of service. So I've just purchased an ViaAqua 1300, and it's currently pumping away. Only $50 - cheaper than I was expecting, though I haven't found any negative comments on the forum yet.

On the downside, the pump fittings were too big for the pipe I'm using (of course), so I've had to bodgy the connectors using gaff tape - not sure how long it will last underwater. Also, it comes with a one year warranty, but the instruction manual says not to use the pump with 'timing devices', so i've probably just voided that. It also says I need to use a 'pre-filter',which I'm assuming is the mesh housing thing which fits over the intake, but I'm going to have to take the mesh out so it doesn't get clogged. Or i might go back the the ingenious and high tech 'plastic cup with holes in it' filter.

Picked up the South Pacific Hyrdronics catalogue, and I reckon I can rig up some sort of NFT extension in time for spring...

Well, the system has been up and running for almost a year - but I've hit a snag: I no longer seem to be getting any growth from my plants.

I've had a strawberry and a silverbeet in the growbed for ages, and they are looking green and happy (though the strawberries are tasteless) - but none of the new seedlings I add grow - they just sit there, and slowly their leaves go brown and die back. They are the only mature plants in the grow bed - so there should be plenty of nutrients to go round. The fish are happy, and eating energetically. The system is definitely cycling properly (water temp stays above 24 degrees now it's warmed up). I've been adding seasol and maxicrop to try to get the growth going - but haven't seen any improvement. It's all very disheartening compared to summer 11 months ago, when my seedlings grew at an almost unbelievable rate!

So, I'm guessing the problem is some sort of nutrient deficiency, probably a trace element? The leaves on the plants aren't going yellow, so it shouldn't be iron (but I've added some chelated iron just to be on the safe side). I'm going to bury a bannana in the grow bed for potassium - but if it's neither of these, what are my options? Are there hydroponic trace element mixtures which are safe for fish?

What is the PH ..... ? Could be nutrient lock-out

Do a test Bootsy... ph, nitrite, and nitrate in particular...

And have a gentle dig around near the roots of the silverbeet plants... and see if the roots have formed a "mat".... and/or are a bit sludgy looking....

I'm actually going to pull down my trough tomorrow... not because it's turned "septic"... or my water is "bad"....

but becuase it's had 18+ months of heavy planting with tomatoes, silverbeet and cabbages... and the bed is pretty full of roots...

Could be some de-nitrifiaction... nitrates converting to NO2, and off-gassing.... due to localised anaerobic zones around the "matted" roots....

If you think this might be the case... and/or you remove the old silverbeet... and root structures.... it will dirty your water... and probably nitrite spike you for a day...

Salt to 1ppt as a precaution... and up your air or pump cycles till the water clears...

Hey...

noticed in the beginning that you used the regular PH test.... be sure to double check the PH with the High Range PH test also...

I keep thinking my PH was 7.4 when I started, but when I checked the High Range PH, it was actually 8.2 at the time...

jT

If not pH or root cramp, I reckon take out the silverbeet, it's going to seed at this time anyway isn't it? Maybe it's just sucking up all the nutes.

Yep, looks like Ph might be the answer - it's about 6.2, and now I feel very silly for being lazy and only checking with the high-range test! Obviously the occasional egg shell I've been tossing in isn't enough to keep it properly buffered. I've added a couple of tablespoons of bicarb to the topup water, and I'll buy some crushed coral today to throw in the fishtank. Thanks everybody! Hopefully I'll have some good photos of plants in full crop soon!