Help with ID'ing a plant deficiency

[marchmaxima]

Hi,

I need help figuring out a possible plant deficiency. I noticed this a few days ago. The tank has been running for 5 weeks now. The first 4 weeks was spent doing a fishless cycle and last weekend the cycle completed and I stocked the tank. The Hygro has been in the tank since the beginning of the cycle.

The tank is 15G with a low light setup (1.2 WPG). It has a single fluorescent 20W globe Aqua glo brand I think? I can look it up if needed. The light is on a timer and is set to output light for 12 hours a day. The light was off during the entire cycle, so this 12 hours of light a day has only been going on this week.

I now dose one a week with Seachem Flourish. Prior to last weekend I was dosing weekly with Wardley Sprout. I changed to the Seachem because I didn't know what was in the Sprout and Seachem Flourish seemed very highly favoured by aquarists here.

Here are the tank params, taken tonight.
Ammonia = 0, Nitrite = 0, Nitrate = 20, GH = 8 degrees, KH = 2 degrees, PH 6.8

Here are some pics of the affected leaves. Sorry they aren't great. The condition seems to be restricted to older leaves, so I'm guessing it's something like a deficiency of mobile nutrients

Those pinkish-looking areas are yellow.

Anyone have any idea what this might be and how to correct it. I'm guessing Potassium at this stage, but I am looking for a second opinion.

Edit; The Anubias Nana in the tank is not showing any signs of a deficiency. Under the sand is a substrate a lot like Eco-Complete (but a bit cheaper). You can't see it and I tried to get a photo , but I couldn't. Some of these leaves have transparent areas on them.

 

[Purrbox]

Here are some pages that list the deficiency symptoms.
Steve Hampton's Deficiency Page
Chuck Gadd's Deficiency Page

If you're lighting is 1.2WPG then it could also be too little light, however if you actually have 30 watts over the 15 gallon (2WPG) then this is less likely and I would look at your nutrients.

What test kit are you using for your Nitrate level and have you calibrated the test? What are your Phosphate levels? This will allow us to rule them in or out. How much of the Flourish are you dosing and how often? Potassium dosing would be advised and may be causing at least part of the deficiency symptoms.

 

[marchmaxima]

Sorry, my error. I have a 20 watt globe over the tank (I've edited the original post which was wrong). The Nitrate test kit I'm using is the one from API. It's the one with 2 bottles, 10 drops each.

I had already looked at Chuck's page. That was quite good. That's what lead me tp think potassium.

I'm not sure what my phosphate levels are as I don't have a test for that. I'll pick up one of those this weekend and post the results. I'll also get something to boost the potassium levels.

 

[Purrbox]

Okay, with 20 watts then insufficient light for the plants is still a possibility. Is it mostly the lower leaves that are being shaded by other leaves that are showing symptoms?

Your Nitrate Test Kit should be fine, but still needs to be calibrated (tested against a reference solution) to determine how accurate it is. For the Phosphate Kit, try to pick up the one by Seachem if you can find it. It a little more expensive, but is just about as accurate as the lab grade kits, very easy to use, and comes with a reference solution for calibration.

For Potassium, you could try to pick up some NoSalt (salt substitute, not sure if it's available in Australia). It's KCl and would work well for dosing Potassium.

 

[marchmaxima]

An update to this...

I finally was able to source a Seachem phosphate test kit and picked it up last night. Water from the tap tests at 0.0ppm and the tank water tests at 1ppm. I'm not certain what that means... Is higher better? What should it be ideally?

I couldn't find any of the NoSalt, so I got some Seachem Potassium and have been dosing twice a week over the last fortnight.

I'm still having the deficiency issues. It's still only the lower leaves and only a few of them.... Two of the leaves are not shaded and get a good amount of light.

I'm due to do a water change tomorrow, so I'll up the potassium dosing to every 48 hours and see if it makes a difference.

Anyone have a suggestion?

 

[Purrbox]

1-2ppm for Phosphate is reasonably good. If you're getting green spot algae then you need to up the dosing.

How much are you actually doesn't with the Flourish Potassium? You need to dose 10-20ppm. Up dosage if your seeing pinprick holes and curling in the older leaves.

 

[marchmaxima]

I'm dosing 1ml. It said on the instructions to dose 5ml for 100 liters. I have a 15G/60 liter tank so I took a thought that 1ml would be right.

I'm not getting any green spot algae at all. My only algar issue is the bucket of diatoms that are turning my lovely white sand brown!

No pin prick holes or curling in leaves, so perhaps it isn't potassium?

This photo shows the leaves (the back leaf) that sort of go mushy around the edges (is that what Melting is?)

And this one (in the middle) shows the same.

On this one the beginning of the leaf, or edge close to the stem has gone.

 

[neilanh]

Maybe I misread something here. That plant was in the tank during the entire cycle, right? YOu didn't run any lighting during the cycle?

If so the plant is most likely suffereing from the extended darkness and now the sudden change to the photoperiod. Allow it some time to recover and acclimate to the new surroundings.

 

[Purrbox]

I'm dosing 1ml. It said on the instructions to dose 5ml for 100 liters. I have a 15G/60 liter tank so I took a thought that 1ml would be right.

That's add 7.6ppm Potassium each dose. This is within the desired range since you're dosing twice a week.

Go ahead and give your dosing routine a couple of weeks to see how the plants react. Then you can tweak as needed.

 

[marchmaxima]

You're right on both counts Neilanh. The plant was in there within a wek of the cycle commencing and was not exposed to my lighting in that time. I didn't actually expect it to survive the cycle period to be honest, but it is absolutely thriving, except for the odd leaf.

I didn't notice any issues with the leaves during the cycle. You might be on to something about the shock of the lighting affecting the plant. I hadn't thought of that.

Will stick with the two weekly doses of potassium a Joy suggested.

Oh, and Joy, just out of curiosity, how do you know that I need 20ppm of potassium and how do you calculate what I'm giving from my dose? You have a super-spreadsheet and a reference table?

 

[Purrbox]

Dosing 10-20ppm of Potassium is a recommendation that I've found consistantly among more experianced aquarists. In adjusting my dosing and watching the plant reactions, I've found that it is a sound recommendation.

I used a dosing calculator to determine the amount of per dose. If you read the dosing instructions on the bottle more carefully, you'll find a formula at the end that allows you to calculate the amount of Potassium being dosed. This is the same formula that the dosing calculators use.

 

[marchmaxima]

Call me daft, but when I enter 1ml & 60 L into that calculator I get 0.76ppm.

Surely that's not correct.

 

[Purrbox]

Call me daft, but when I enter 1ml & 60 L into that calculator I get 0.76ppm.

Surely that's not correct.

Nope that's correct. I obviously mistyped something either in the calculator or my post last time. I was expecting you dosing to be on the low side since you were using the recommended dose instead of the calculator. I was surprised when it didn't come out that way. The Flourish Potassium is a very week solution (as are most of Seachem's macro ferts) which is why the dry ferts end up being so much more economical. You would want to up your dosing to 6.5-13ml to get the recommeded 10-20ppm of Potassium with two doses.

 

[marchmaxima]

Hmm. Okay then. That stuff is really expensive ($20 for a small bottle) so I think, as you suggest, I'll be on the lookout for a dry alternative.

And that begs the question... what amount in ppm should I be dosing the Seachem Flourish? I'm currently dosing 1ml once a week. Again, I'm just following what the bottle says.

 

[pitt420dude]

I'd follow what the bottle says until you get your dry ferts.

Greg Watson or Rex Grigg sells em. I just got mine from the latter and they come well packaged, clearly marked and with a suggested dosing regime.

 

[Purrbox]

Unfortunately since Sharon is in Australia, she probably won't be able to get the ferts from those sources (definately not the KNO3). Check around locally for hydroponic stores, they'd be your best bet for dry ferts locally.

 

[marchmaxima]

Yeah, I'll check the local hydroponic place. There's a few around the area i can try.

And for moments like these, the father-in-law comes in very handy.

If I send him an email, he'd have some dry ferts sent to their house in South Carolina and it'd be on it's way to me in a week.

Worse case scenario.

 

[marchmaxima]

Found this:

I need something like the potassium nitrate, don't I?

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[FONT=Arial, Helvetica, sans-serif]Sulfate of Potash (SOP)[/FONT] [FONT=Arial, Helvetica, sans-serif]Potash fertilisers other than MOP are used where special crop or soil needs exist.[/FONT]
[FONT=Arial, Helvetica, sans-serif]Potassium sulfate (referred to as Sulfate of Potash or SOP) is used in crops that are sensitive to chloride or fertiliser burn like tobacco, pineapple or avocado, or where sulfur is deficient.[/FONT]
[FONT=Arial, Helvetica, sans-serif]Its nutrient composition is approximately: [/FONT]

[FONT=Arial, Helvetica, sans-serif] Potassium: 41% [/FONT]
[FONT=Arial, Helvetica, sans-serif] Sulfur: 18%[/FONT]
[FONT=Arial, Helvetica, sans-serif][/FONT][FONT=Arial, Helvetica, sans-serif]Potassium Magnesium Sulfate[/FONT]
[FONT=Arial, Helvetica, sans-serif]Potassium magnesium sulfate is an excellent source of three of the major nutrients - potassium, magnesium and sulfur.[/FONT]
[FONT=Arial, Helvetica, sans-serif]Its nutrient composition is approximately:[/FONT]

[FONT=Arial, Helvetica, sans-serif]Potassium: 18%
Magnesium: 11% o
Sulfur: 22%[/FONT]
​

[FONT=Arial, Helvetica, sans-serif]It is used mainly for high value crops, where all three of these nutrients are required. It is also included in many 'complete' fertiliser products since it supplies several nutrients. While it is 99.7% water soluble, the rate of solubility is too slow for application in fertigation systems.[/FONT]
[FONT=Arial, Helvetica, sans-serif] Potassium Nitrate[/FONT]
[FONT=Arial, Helvetica, sans-serif]Potassium nitrate, sometimes also known as saltpetre, is often used in foliar sprays or fertigation because it is highly and quickly water soluble. [/FONT]
[FONT=Arial, Helvetica, sans-serif] Its nutrient composition is approximately:[/FONT]

[FONT=Arial, Helvetica, sans-serif]Potassium: 38%
Nitrogen: 13%[/FONT]
​

[FONT=Arial, Helvetica, sans-serif]Potassium nitrate has application as a potassium source for crops which are highly sensitive to chloride, such as tobacco.[/FONT] [FONT=Arial, Helvetica, sans-serif]It is an oxidising agent and should be handled and stored with care.[/FONT]
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[marchmaxima]

Never mind - I found the answer

• KNO3 aka Potassium Nitrate is used to primarily dose nitrates or NO3. It does have the side effect of dosing a small amount of potassium.
• KH2PO4 or Mono Potassium Phosphate is used for dosing phosphates or PO4.
• K2SO4 or Potassium Sulfate is used for dosing potassium.
• Plantex CSM+B is a trace mineral mix.
• A gallon or so of RO/DI or distilled water.