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Unlocking the Secrets to Prevent Nutrient Lock-Up in Hydroponics · Hydroponics Daily

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  Hello there and welcome back to
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  Hydroponics Daily, your go-to podcast for everything soilless cultivation.
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  I'm your host Dr. Russell Sharp and today we're talking about nutrient lock-up.
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  That's situations when nutrients fall out of solution and become unavailable
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  to your plants and then because they're unavailable the plants becomes deficient
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  in that nutrient and then eventually will show symptoms of deficiency.
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  Growth rates will drop, crop quality will drop, and you'll start to cry. So let's prevent that.
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  The easiest way to prevent that is to use gold leaf fertilizer if you're in
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  the US or liquid gold in the UK because it contains every essential nutrient
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  for plants in a fully soluble form and it's pH perfect.
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  So even when you add other additives that might swing the pH or add other nutrients
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  then you're not going to get lock up.
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  But if you're using a standard hydroponic fertilizer
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  or using your ph swings
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  out of control then you may get lock up and
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  we'll talk about in this episode all of those different situations
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  and go into more detail about them so we
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  can split them into two different areas there's one where
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  there's a chemical interaction and the the nutrients
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  interact and they become insoluble sometimes it's
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  not even a nutrient sometimes it can be an additive
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  a biostimulant a great example there is chitozan we
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  make and sell chitozan as a biofungicide but if you
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  add it to an iron fertilizer or you add it even to
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  a seaweed fertilizer all of the nutrients can come.
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  Out of solution especially the iron iron wants to come out
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  of solution and chitozan wants to take it out of
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  solution so um they're a match made in heaven so you can get iron deficiency
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  you add that to your too much of that to your to your
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  growing conditions for example but normally it's fertilizers
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  that are negatively interacting and they
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  get lock up another word for lock up is look up
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  is chemical precipitation so you may
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  have done experiments in in high school or
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  at university where a precipitant is formed
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  the the solid at the bottom of the test tube and that's exactly what's happened
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  in your fertigation tank or in knee or roots or in your soil even it can hurt
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  and that's insoluble compounds are being formed so he said they can occur can
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  even occur due to improper mixing or from water chemistry,
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  the hard water can happen.
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  A very common one is if you're using a PK product and you put it into hard water,
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  you might see that it goes cloudy.
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  And that's because a lot of PK products are based on monopotassium phosphate,
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  which is the cheapest form of potassium phosphate.
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  And that goes cloudy when you add it to hard water. And so you probably,
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  if you're using RO water, that's the best option.
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  And that's because calcium and phosphate.
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  When they combine, they form calcium phosphate. So that might be the calcium
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  from hard water, it might be the calcium in an additive.
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  And this is what forms when you add your A. If you were to add an A and a B
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  fertilizer together in the bottle without any dilution, you'd get calcium phosphate
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  forming within a few hours.
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  And even when it's diluted, this can occur in your fertigation tank.
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  So you have to be really careful.
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  And especially if the pH creeps above 6.5, you can get even more formation of this.
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  So you'll get a white sediment in your reservoir tank
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  it will be a hard white sediment so never mix
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  concentrated calcium and phosphate together always dilute
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  them separately and never mix your asian
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  bees without the water first and always control the ph because
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  calcium phosphate is the thing that is in bones
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  and you think about bones they survive for thousands of years in the ground
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  without breaking down because calcium phosphate doesn't dissolve very easily
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  if at all it's like it's going to stay as long in the ground as say a plastic
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  is so once it's formed that your nutrients are never going to come back out
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  of solution no matter what you do to them another very common.
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  Precipitant that occurs with phosphate is iron
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  and phosphates forming iron phosphates or
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  iron and hydroxide forming iron hydroxide iron
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  hydroxide so the iron loves to
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  fall out of solution and it's probably
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  the most common deficiency you'll
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  see on the likes of reddit is iron deficiency
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  chlorosis so that's why all good fertilizers contain chelated iron so if you
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  see iron sulfate on the list of ingredients you know that the formulation is
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  a cheap and cheerful one it might not be cheap to you you might have bought
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  it for a high price but it was very cheap for the manufacturer to make.
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  So you want one that is chelated, either with organic acids such as ammonium
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  citrate or with EDTA, DTPA, EDDHA.
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  Basically, if you see four or five capital letters together,
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  you know that it's chelated or you see the words, you know, ammonium citrate.
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  So that will help with.
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  Prevent the formation of iron phosphate or iron hydroxide again if the pH rises
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  iron will fall out of solution so always make sure your pH doesn't rise because
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  you will get cloudy precipitants,
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  and then when the pH rises again other nutrients will fall out of solution even
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  if they're not forming things like reacting with the phosphates so manganese
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  zinc and copper they will fall out of solution and form a precipitant as the
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  pH rises so you get a lot of micronutrient deficiencies use at high pH.
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  That's why we say the ideal pH range is 5.5 to 6.5.
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  Some people may say that it's narrower than that, but you don't want to be messing
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  around with pH once it's in that sweet spot.
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  You can get sulfate reactions as well. So calcium will react with sulfate to
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  form calcium sulfate or gypsum.
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  That's really, especially in sulfur-rich additives,
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  they're combined with high calcium inputs so say
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  you're using high calcium inputs with a very
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  high sulfur product a lot of the additives in
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  flowering that improve growth are very high in sulfur so you put both of those
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  a CalMag and one of those in and then you could get calcium sulfate forming
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  which will dissolve over time but by the time it's ready to harvest your crop
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  it's that's probably not the timeline that they're going to dissolve we're talking.
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  Months or years so if you're growing a perennial crop
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  you don't need to worry too much about calcium sulfate formation in
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  the long term but you do if you're growing a crop that's
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  going to be harvested within weeks you can get potassium and
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  magnesium competition that's not so much precipitation they
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  just interfere with each other's uptake and so that
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  would become under lockout so you could get it
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  would still be classed as lockout even though it's not a precipitation so
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  you can get magnesium deficiencies if you're adding too
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  much potassium that's often seen in tomatoes and pepper
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  crops where potassium is boosted during fruiting and
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  as i say hydroponic fertilizers normally they have loads and loads of potassium
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  and so that's what another reason why calmags are always useful just you don't
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  need to worry about adding potassium in hydroponics i've never known potassium
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  to be deficient in any fertilizer or any crop really maybe some.
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  Maybe tomatoes if you're not boosting it during fruiting you
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  get something called yellow collar i think if you
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  if you don't give enough potassium but most crops there's loads of
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  potassium just because of the way you get the nutrients in that potassium is
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  that is the additive that gets nitrates and things like this in so common
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  mistakes is dial is mixing your
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  fertilizers before they're diluted in water so make sure you
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  add the water first never mix an a and a b together
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  never mix a pk with a calmag for example
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  that's a disaster waiting to happen avoid combining
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  chelated nutrients with strong oxidizing agents
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  like hydrogen peroxide that can destroy the chelate that's another good tip
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  and never use unchelated iron if it contains iron sulfate in the ingredients
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  it's a very cheap and nasty one so and then you've got your tap water issues
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  so high bicarbonate or carbonate levels in the hard water can raise the pH, promoting lockouts,
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  interfering nutrient solubility, and reduce buffering capacity.
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  So if you're struggling with hard water,
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  think about using reverse osmosis water or acidify the water source or both.
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  Well, you wouldn't need to use both, would you? You could use a dechlorinator
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  and an acidifier, I suppose, if you didn't have access to reverse osmosis.
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  That would be the option.
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  Either reverse osmosis or acidifier, then dechlorinate would be my options because
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  if you've got hard water, it's probably going to have a high chlorine level as well.
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  So monitor your pH, monitor your chlorine levels your hardness levels make sure
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  you stir and agitate your nutrients when you're mixing them don't just rely
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  on diffusion used to have a university lecturer who said that you know we do
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  practicals and need to shout too many of you students rely on diffusion for mixing your.
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  Your experiments you if you just add one
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  ingredient to the fertigation tank and it's very still then if
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  you add your a and then your b if you've not stirred it then
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  you could get localized concentrations and you could get
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  precipitation there so always make sure you mix everything after
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  you've added it to your tank you could potentially you
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  always use if you're a large scale grower and you're not
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  using gold leaf or liquid gold as it's known
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  in the uk then you will
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  need separate a and b tanks don't just add them into the same tank you'll
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  find in the us a lot of the nursery growers small scale
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  growers just use soluble crystal what
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  they call crystal fertilizer so like a big bag of
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  fertilizer and then they dump that in and then they add sulfuric acid
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  later on to ph correct and they
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  will get lockout and they also get loads of algae growth in their
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  fertigation tanks but it's a big issue in
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  those sorts of mom-and-pop style nurseries that
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  you'll find in sort of you know midwest america growing
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  cyclamen and lettuce and things like this so lockout
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  is a big issue in medium scale growers if you're using kelp or seaweed extracts
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  make sure you don't add then you could get issues with the lockout of anions
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  things like sulfates potentially if you're using silica you can raise it'll raise the ph and lock out.
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  Other nutrients so just be careful with additives
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  that have got an extreme ph or have ingredients that
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  can precipitate other things out so seaweed's got
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  alginic acid in so alginic acid will
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  link to calcium and calcium you get calcium alginate which is insoluble so your
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  seaweed extracts will react with calcium as i said your chitosan that will react
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  with iron your silica will react with anything that's acidic and you'll get
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  like this hard glassy precipitant forming which is not cool and it'll raise the pH.
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  Seaweed extracts can be any pH so they can be pH 12 or pH 4 so always test the
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  pH of your seaweed extract that could be the thing that's changing your pH and
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  causing your issue that you didn't know about.
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  You might think of it as being this innocuous natural extract
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  which it could be or it could be one of the cheap and
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  cheerful pH 12 products so always check
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  that if you're having issues and remember don't overload don't
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  add extra fertilizer more is
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  not better it's never better when it
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  comes to fertilizers you're only going to get issues if you add too much fertilizer
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  always add less if all the right amount that it says on the label some fertilizer
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  manufacturers actually dilute their products because they know that people are
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  going to add too much one of the very big brands that comes from the netherlands for example.
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  Utrema and gold leaf us we
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  don't do that we state that the amount you're
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  supposed to add on the label if you add more than that that's your
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  problem we've told you what is the optimum and we're
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  going to assume that you're sensible so in hydroponics
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  the clarity of your fertigation solution isn't just
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  visual it's chemical and it leads to important
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  issues with your plants so you're getting cloudiness you need
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  to look at what's forming what could potentially be
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  forming and is that the reason your crop isn't growing as
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  well as it should be so keep your solution well balanced
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  well mixed and within the ph range don't be
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  adding calcium to phosphate iron to
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  phosphate and things like this and you won't get any
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  lock up make sure you've got a nice calcium so potassium
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  to magnesium ratio and if you've got any
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  negative interactions or you think i've missed any then please do get in touch
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  if you've gotten any issues around the growth then i'm more than happy to look
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  into them for you may not be a definitive answer but just like when you go to
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  the doctors i could give you some potential options for what it could be and
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  so that's been hydroponics daily for today thank you very much for listening
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  and until tomorrow goodbye.