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seeds germinating but not continuing to grow & yellowing

Discussion in 'Plants' started by AReiher, Apr 5, 2012.

  1. AReiher

    AReiher New Member

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    Hey there, I am very new to Aquaponics but we just bought a house with a fantastic set up. We have just bought 50 rainbow trought for our 1000L tank which feeds a large assortment of large tubs of plants in a hothouse. My problem at the moment is that we bought the house 4 weeks ago and on the day we bought it I planted seeds (lettuce, rocket, basil, bok choy, silver beet) and they germinated really quickly and grew a little bit but then either died off or have not grown much since. I later planted baby leaf gourmet mix and they germinated and grew a little bit but the leaves have turned yellow and they have not continued to grow. I have baby broccoli growing and it seems to be doing okay but not growing fast like the aquaponics system should (i.e. planted 3 weeks ago and they are about 3-4cm). The established plants in the hothouse that were already there when we moved in (lemon grass, asparagus, sweet potato, celeriac) are all doing great. I've watched quite a few of Murray's video tutorials and added 1 tsp of chelated iron yesterday. Does anyone have any other recommendations for me? Thanks, Angela
     
  2. silloth52

    silloth52 Member

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    have you done the recomended water tests,eg
    ph,ammonia,nitrite and nitrates
    the results will go a longway to determine any likely problems
     
  3. benwalters

    benwalters Member

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    Hi Angela, are the sweet potato etc plant in hot house in ap system or seperate?
    Try to post some pictures
    are fish okay? I'd be holding back on feed if you have a plant problem cause you may have a fish problem soon if not sorted quick
    if established plants are in ap they may be hogging nutrients. , this is good news for fish, but you need a test kit fast as mentioned above...
    With ap you need to keep fish happy first
    if seedings aren't working try getting some more advanced plants in there
    even try weedy things like mint to experiment
    if there are no plants in ap you will need water changes and lay off fish feed
    if there are established plants in ap then growbeds may need an overhaul
    anyway best of luck and keep posting,
    ben
     
  4. AReiher

    AReiher New Member

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    Thanks for your help. Yes I need to test the water. So which test kits do you recommend I use? In regards to the hothouse and plants - I have established plants in the hothouse - a massive sweet potato vine, lemon grass, ginger, celeriac, there's even some kiwi fruit growing. I have had a closer look at the sweet potato and there's definitely an iron deficiency from the look of the leaves - green veins and yellowing leaves. The fish seem okay but I did have a dead one this morning. They are active and only eat a small amount of hand feed so they must be getting enough from the plants. I think I said in previous post I added chelated iron - a tsp. It is a pretty big system - should I add more?
    Will organise and add photos later today.
     
  5. benwalters

    benwalters Member

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    Hi Angela,
    can i clarify if the "massive sweet potato vine, lemon grass, ginger, celeriac, there's even some kiwi fruit growing" are growing in the aquaponics system?
     
  6. benwalters

    benwalters Member

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    the test kit most people use is " API freshwater master test kit"
     
  7. benwalters

    benwalters Member

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    hi angela, i have not grown trout but my understanding is that they like good quality water, in particular, well oxygenated water

    your seedling issues sound bad, but if i were you i would concentrate on the fish at this stage
    50 trout is a lot in a system that is not working 100%

    have you got a rainwater tank? this is usefull for top ups as town water is toxic to fish due to chlorine

    photos would be great to get an idea of your system, also test results

    the fish fatality you have had may mean nothing or be due to disfunctional system

    if system doesnt have issues plants grow well, fish are active and hungry, usually not dying
    if system is basically okay make adjustments slowly

    if system has issues-
    -reduce / stop feeding
    -add oxygenation
    -add salt to water (pool salt not table salt 1kg per 100 ltrs)
    -do water changes (max 1/3 per day)

    have a great easter
    ben
     
  8. AReiher

    AReiher New Member

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    Hi Ben, Thanks for helping. I will get water tested ASAP - not sure how long that will take considering its Easter weekend. But in answer to your qns: The plants you asked about, are in the aquaponics system, in grow beds with flood and drain system. Everything in the hothouse is conncected to the ap system. I use rainwater from a tank to top up the system. The fish seem very active and happy. The water is clear and oxygenated and circulating well with timers etc, i.e. the water floods every hour and drains as the tubs fill. I have attached some photos of the system. Photo 1: from hothouse door - trout in tank down bottom. Photo 2: Grow beds and trout tank, Photo 3: View of RH side of hh with sweet pot vine, Photo 4-5: Sweet Pot leaves & baby lettuce/gourmet mix yellow leaves, not growing (planted 3 weeks ago), Photo 6: Trout tank from outside access/view, Photo 7: Holding tank for water from trout tank which then flows to plants in hh. Some of the grow beds will be overhauled in the next few months. Thanks again for taking the time to help out.
     

    Attached Files:

  9. benwalters

    benwalters Member

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    hi again, its good that the established plants are there
    it will be interesting to see what readings you get when you test water
    sometimes seedlings struggle due to small root systems and heat from medium when there is a long drain cycle
    perhaps you could buy some larger seedlings and plant them a little deeper , or increase flood cycles (15 min flood , 15-30 drain )

    the water temperature is important with trout, under 20 degrees is the go, with increased temp more oxygen is needed , this may also benefit from extra flood cycles if grow beds drain back directly to fish tank
    was the system unstocked for a period of time before you bought the house? - if so bacteria in gravel may need to build up again

    anyway, dont worry to much this weekend cause there is chocolate to be eaten

    cheers
    ben
     
  10. Yabbies4me

    Yabbies4me Administrator Staff Member

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    I'm sure Ben meant 1kg:1000Ltrs, not 100Ltrs... :p

    ...but in saying that, I wouldn't salt unless you have determined there is a reason for doing so, ie:

    - Nitrates above 1.0 (salt to 1ppt... 1kg:1000Ltrs)
    - Fish showing signs of disease (salt to 3ppt-6ppt, depending on disease present)

    I also wouldn't do any water changes unless your Nitrates or Ammonia are getting way too high, about 2.0 for Nitrites (as long as you started salting at 1.0), and Amm level varies depending on temp and water pH... it's covered on a number of threads on here somewhere, or you can find charts on the net.

    Doing water changes if you have nutrient deficiencies will probably only exacerbate the problem... The first thing you need to do before undertaking any drastic measures, is test your water pH!... also your Amm, Nitrite and Nitrate levels... doing anything before taking these measurements would be like driving at night on an unlit road... without headlights!!!

    If your water pH is above 7.5 you'll probably have an Iron deficiency. Having a number of large, established plants in the system you may also have a Potassium deficiency.
    If your water pH is in the 6's, you could easily add Potassium with the addition of one slightly heaped teaspoon of "Eco-fungicide" (Potassium bicarbonate) per 1000Ltrs.
    If your water pH is 7.0 or higher, then I wouldn't add the Potassium bicarbonate to your water, it will buffer the pH up. Foliar spray it instead, at the rate suggested on the container.

    ... but again, test your pH, Amm, Nitrite and Nitrates first… most ricky tick!

    Cheers, Yabbies.
    .
     
    Last edited: Apr 6, 2012
  11. benwalters

    benwalters Member

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    re. Bad salt concentration mistake......well spotted yabbies, my bad !


    who would have thought a 0 or 2 would matter !!!!
     
  12. Yabbies4me

    Yabbies4me Administrator Staff Member

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    I reckon the extra zero would matter if it had disappeared off your bank account balance!... :D
     
  13. benwalters

    benwalters Member

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    Yabs, no difference between 00 and 0,
    just saying.....
     
  14. AReiher

    AReiher New Member

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    I have completed the water testing:

    Ph = 7.4
    Ammonia = 0
    Phosphates = 0.25

    From my understanding Ph should be between 6-7 and I have already added chelated iron a week ago so it was probably higher??

    Ammonia is supposed to be near 0 so that seems okay

    Not sure on phosphates...

    There are no changes in anything since the first post - oh except that some native rodent got in and ate a whole heap of my lovely sweet potatoes and not sure what to do about the animal...?

    Angela
     
  15. benwalters

    benwalters Member

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    Hi I think your ph is fine
    the other tests that are usually done are nitrate and nitrite
    not sure about phosphate testing , I've never heard of anyone testing it
    are plants looking any better?
    Re. Rodent , best option would be to build it out perhaps
    cheers
    ben
     
  16. AReiher

    AReiher New Member

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    Hi Ben
    I got the water testing equipment from school where I work - I don't work in the science dept tho but this is what we were using to test the water in our creek - anyway the kit didn't have nitrate and nitrites but I should be able to get that as well - maybe the iron I added will help. Should I add more soon and when? I really can't believe the virtual non growth of what I have sown - I would have been picking by now if I had just sown in pots or the ground.
     
  17. benwalters

    benwalters Member

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    Hi angela, I'm not sure what the problem is, if there is nutrient problems use foliar feeding (spray leaves with fert( fish safe)) most people don't sow seeds direct into growbeds, I'd be interested to see how you would go Planting some more advanced plants in growbed
    ap systems can take time to operate well, and some crops are not sucessful
    all the best
    ben
     
  18. Yabbies4me

    Yabbies4me Administrator Staff Member

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    Yep!... point taken Ben!

    .

    Get it?... point taken!... geez I crack myself up... :D

    .

    ...the decimal point...

    .

    ...okay I give up!... :frown:
    .
     
  19. Rob's Green Thumb

    Rob's Green Thumb New Member

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    Well just by looking at your photos the iron you added should do the trick even the older plants were showing signs of light yellowing. You may also have to bump up the amount of iron your useing a bit some types of plants tend to soak up more then others. If your water test come back alright just bump up the dose of iron and see if that dont help as long as the ph being to high isent the problem.
    Little extra iron wont hurt anything I use about a teaspoon of it a month on my 10 gallon system thats been running for about a year the fish dont seem to care if the waters a little tea looking and the water will clear up in a month as the plants soak it in I know this because as soon as the water runs clear the leaves start to yellow.
     
  20. Jacobtaylar

    Jacobtaylar New Member

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    That is not good signs that the seeds germinating but not continuing to grow & yellowing. This is one of the bad decedents happens in the growing of plants and need to be cured immediately otherwise will spread in to the other plants.
     

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