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Plants are yellowing and I added iron.

Discussion in 'General Aquaponics Discussion USA & Canada' started by Robbee, Apr 25, 2017.

  1. Robbee

    Robbee New Member

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    Country:
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    Florida
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    I have been adding Iron and micro nutrients for about 2 weeks and plants are still yellowing. System is about 2 months old with fish. PH 7.2 ammonia .25-.50 Nitrites .25 Nitrates 160 ppm EC ( Water) has 300 ppm. The Iron is Ferrous iron and the micro nutrients well heres a few pictures. Could someone please help save my plants. The tomatoes and peppers and egg plants are doing fine but the squ 4.jpg 1.jpg 9.jpg 11.jpg 8.jpg 3.jpg 4.jpg 1.jpg 9.jpg 11.jpg 8.jpg 3.jpg 4.jpg 1.jpg 9.jpg 11.jpg 8.jpg
     
  2. Terra

    Terra Active Member

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    Welcome to the forum nice little system

    First step is feed quality

    What fish do you have , how many , and what are you feeding them

    How much "Wet" gravel do you have in your system

    Usual feeding fish / plants in a new aquaponic system is quality feed such as is used in aquaculture and supplement with seasol

    Fruiting plants usually struggle in new systems as it takes time to build up our nutrient base

    Short term get some Iron foliar spray , leave one plant so you can see if treatment is successful

    Link to explain iron / ph relationship https://en.wikipedia.org/wiki/Iron_deficiency_(plant_disorder)

    Why are you getting a nitrite reading in a 2mth old system are you overloaded with fish ?? where is the excess ammonia coming from .

    Common deficiencies in new systems are iron , potassium , magnesium , and calcium

    Calcium / magnesium balance is interesting to say the least .
     
    Scott-dover-Delaware likes this.
  3. Yabbies4me

    Yabbies4me Administrator Staff Member

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    Hi Robbee, welcome to the forum.

    Edit: I see Terra has already covered a few of the following points. I was typing this out over a couple of hours, in between watching our Anzac ceremonies on the telly and preparing lunch etc.

    Going by your Ammonia and Nitrite readings it is apparent that your system is new and not yet cycled (and/or possibly overstocked). Flowering/fruiting plants do not do well new systems that have not yet had time to build up a sufficient bank of nutrients to maintain them. It is widely recommended that you only grow small leafy greens, such as lettuce, Asian greens, herbs etc, for the first 4-6 months in a new system, to allow the system time to develop this nutrient bank.

    Even in a well established system, it is advisable that a maximum of 1/3 of the plants in the system at any one time be fruiting plants, the rest should be less nutrient hungry, smaller leafy greens and herbs etc.

    Your squash plants are definitely suffering from a deficiency, which nutrient is hard to tell from the pics. Again, it is hard to tell from the pic, but the Capsicum/Bell pepper in the background of one of the pics appears it may suffering from a Calcium deficiency. Your Squash plants are also suffering from powdery mildew.

    When you say your Nitrate level is 160ppm, do you believe this to be accurate, or is it possible that you are using a test kit that only reads to 160ppm and the actually reading could possible even be higher?... High Nitrates can have a number of detrimental effects, such as: Causing Iron in the water to be less available to the plants, and creating a general nutrient imbalance between the Nitrate and your mineral nutrients, ie: Potassium, Magnesium, Calcium, and trace elements etc. High Nitrates also inhibit the growth of seedlings.

    The fact your system is two months old and is still showing Amm readings, could suggest it is possibly overstocked. However, a fully cycled, yet slightly overstocked system would in most cases not show signs of Nitrite, as it is very quickly converted to Nitrate. This leads me to believe your system is still not fully cycled.

    How many fish are in the system, type, size?... How much bio-filtration, ie: wet gravel, do you have in the system?

    My suggestions to you would be as follows:

    (1). Do a number of partial water changes (about 25-30%), each a couple of days apart, using water that has been "aged" ie: aerated and exposed to sunlight for at least 24 hours. I would aim to get the Nitrates down to at least 80ppm.

    (2). Remove a good portion of the flowering/fruiting plants, especially those that are obviously struggling.

    (3). Plant every spare space in your grow beds with seedlings of fast growing leafy greens, to help keep the nitrates under control.

    (4). Stop thinking of your aquaponics system as a hydroponic system and start thinking of it as an eco-system that requires time to establish itself, find a balance, and develop a nutrient bank. Stop adding the Seachem product. Possibly add small regular doses, ie: a capful, or 15ml, of a seaweed extract (such as Maxicrop) per 500L, per week, to help with trace elements etc while the nutrient bank is building.

    (5). Remove any of the worst affected leaves from your squash plants that have obvious of signs of powdery mildew, and treat the remainder with a foliar spray of Potassium bicarbonate every 5-7 days.

    (6). Foliar feed any plants showing obvious signs of nutrient deficiency with a good quality foliar feed, or Maxicrop, every week until the system finds it's balance and the plant growth improves.

    (7). Ensure your system is not overstocked. Fast growing fish, such as our Aussie Barramundi, Trout, Tilapia etc, basically any fish that gets to plate size in under 12 months from fingerlings, require 25L+ of wet gravel per fish. Slower growing fish, such as our Aussie Silver Perch, require a minimum of 20L+

    Cheers,

    Hayden.
     
    Scott-dover-Delaware likes this.
  4. Robbee

    Robbee New Member

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    I was feeding the fish everyday ( over feeding ) so I cut back to feeding every other day and enough it takes them 1 min to eat all the food. I feed them sportsman floating fish food. High protein style.There are 20 tilapia about 1-1.5 lbs each in a 250 gallon fish tank and a 250vgallon sump tank. ( both ICB Tanks ) There are 4 grow beds 12x12x16 8 inch's of lava rock and 4 inch's of gravel. My test system only goes to 160 PPM nitrate. I have no filter system. I am going to add a swirl filter. Do I need to add more gardens and a bio filter?Thank you for your help.
     
  5. Yabbies4me

    Yabbies4me Administrator Staff Member

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    What size is are your grow beds?... are those measurements in inches?... so 4 x GB's of 300mm L x 300mm W x 400mm D?

    A swirl filter will remove the fish waste solids, which contain all the mineral nutrients for your system, such as: Potassium, Calcium, Magnesium, Phosphate, trace elements etc, but will not resolve your high Nitrate issue. Nitrates are formed from Ammonia, a gaseous element that is soluble with in the water and only about 20% of the Ammonia in a system is contained in the fish waste solids, around 80% of the Ammonia released by fish is through respiration and urination. So if you do plan on installing a swirl filter, you should also plan on creating some form of bio-digester to treat the solids collected and release much of the mineral nutrients back into the water.

    A swirl filter prior to your GB's may increase the period between GB clean outs, but IMO they are not required for most backyard type systems, if set-up well. I prefer to allow the worms in my GB's access to the fish waste so they can break it down and release the nutrients.

    As far as needing a bio-filter is concerned... Gravel filled GB's are just that, so why not kill two birds with the one stone?... add more GB's, therefore adding more bio-filtration and increasing your plantable area... More plants equals less Nitrates.
     
  6. Robbee

    Robbee New Member

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    The grow beds are 12 inch's deep 12 inch's wide and 16 feet long.

    Worrying works... 90% of the things I worry about never happen! That is so true "Yabbies"
    I removed about 1/3 of the water and refilled with well water that has Iron in it. I will check the system in the morning. I will get some EDDHA Iron from Amazon and try and bring my PH down. Do I have to many fish?
     
  7. Robbee

    Robbee New Member

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    There are 20 tilapia about 1-1 /2 pounds each. I use sportsman floating catfish food high protein.
    Beds are 12 inch's high 12 inch's wide and 16 feet long.There are 8 inch's lava rock and 4 inch's of gravel on top.
    Yes,The test kit only goes to 160 PPM.
    There are 20 tilapia about 1-1 /2 pounds each. I use sportsman floating catfish food high protein.
    How many fish is good for 64 square feet of G/B? Thanks for your help. Robbee AKA Robbie I am a bee keeper too.
     
  8. Yabbies4me

    Yabbies4me Administrator Staff Member

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    Doh!... I should've realised that from the pics.
    Your GB's are around 4,870mm L x 300mm W x 300mm gravel depth, so a total gravel volume of around 435-440L per GB... If flooded to 250mm you will have a wet gravel volume per GB of around 365L... Divided by 25L, gives you a safe fish stocking capacity of 14.6 fish per GB (unlucky break for that 15th fish).

    With 4 of these GB's your max safe fish stocking capacity would be about 58 fish through to a plate size of about 500gm... So you are definitely not overstocked. The fact you have Amm and Nitrite readings shows that your system is not yet fully cycled. Once the Amm and Nitrite both drop to 0.0ppm the system is cycled.
    .
     

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