# Plant deficiencies



## bkhoshza (Aug 24, 2012)

Hi,

My problem is with what I think are some plant deficiencies that I am experiencing with Staurogyne Repens which is considered a medium light plant. Not all but most of these plants have older leaves yellowing and parts of the leaf is reabsorbed leading to dead patches and eventually the loss of the leaf. I believe this is signs of phosphate deficiencies or maybe even nitrogen deficiencies. 
I also have Cryptocoryne x willisii which is doing well and not showing any signs of deficiencies.

I posted this in the El Naturel forum mostly because I know everyone here would have be following the Walstad method and would maybe have experienced similar things in the past and knows how to deal with it. If you've experienced plant deficiencies in Walstad tank, how do you handle it?

About my tank:
I have a standard 10G planted tank with a 15W florescent light bulb over it. Tank substrate is regular potting soil which was soaked and drained 3-4 times before being placed in the tank. Tank is now three months old and is about 75% planted. At the moment I only have guppies in there and as usual with guppies there is a lot of them, about 30. Water parameters have been stable at GH:180ppm kh:40ppm ph:7 Nitrite:0 Nitrate: 20ppm since the second week after the start of the tank. Never had problems with algae. Run a Aquaclear 50 HOB filter.


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## Luffy (Aug 23, 2012)

Tell us more about your lighting situation? One 15w bulb seems like very little light to me. Crypts are more adaptable to low light in my experience so it could be that your S. Repens just isn't getting quite as much light as it would like. 
I have a 10 gallon with Crypt Parva, Crypt Undulata, Val Spiralis and some Ludwigia Repens and two 15w bulbs (the curly florescent 60w replacements). The Val had a hard time with my original lighting until I upgraded to what I have now, but the Crypts seem to grow just as well in both conditions. Maybe more light is all you need.
I just go down to Orchard Supply and grab one of those clamp-on shop lamps with a 6400k spiral florescent. It's like $15 bucks. Not bad for aquarium lighting.


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## bkhoshza (Aug 24, 2012)

Thank you for your response.
I thought it would be light but was worried I would disturb the balance if I added more light to the tank.
Regarding my lighting situation it is just the one 15W florescent bulb. I will try upgrading.


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## AaronT (Apr 26, 2004)

Are the deficiencies recent or have you always experienced them?

The reason I ask is that I almost always experience potassium deficiencies in soil tanks after 3-6 months of them being setup.


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## bkhoshza (Aug 24, 2012)

Hi Aaron,

This is my first Walstad tank and I have been experiencing this from the beginning. 
I have upgraded to 2 x 18W (3.6wpg) tubes and am leaving them on for nine hours a day, doing 4 hours in the morning with a 3 hours break in the afternoon and then 5 hours in the evening and off over night of course. Really hoping that this doesn't throw anything off. I originally was looking for an upgrade of 2-2.5wpg but was not able to find one that was worth it.


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## Luffy (Aug 23, 2012)

More light shouldn't hurt anything as long as you're not adding some ridiculous amount. A longer photo period probably wouldn't hurt either. I believe Walstad's method calls for at least ten hours of light per day. I would try that before trying to dose with fertilizers. I've had mine going for about six months with no nutrient deficiencies.


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## Skizhx (Oct 12, 2010)

wpg is a pointless measurement. The less you use it, the better the advice you'll be able to get.

I had similar problems in a similar tank with the same lighting.

The problems also weren't resolved when I doubled the lighting and extended my photoperiod to 12 hours.

What did resolve the problem though was switching to spiral CFL's.

The problem in my opinion is that the fluorescent tube bulbs that are manufactured at that length just have terrible spectrum for plant growth, and better bulbs aren't manufactured (at least none that I could find).

'daylight spectrum' spiral CFL bulbs with incandescent fixtures seem to have worked much better for me, and have been quite convenient and cost effective.


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## Luffy (Aug 23, 2012)

Skinzhx may be right. When I upgraded it was from a single tube to two daylight spirals. My plants went nuts when I switched over.


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## bkhoshza (Aug 24, 2012)

Well after switching to two fluorescent tubes my plants are certainly growing a lot faster and are greener but still showing signs of deficiencies (K in particular). Do you still think that this would be a sign of insufficient light spectrum? Or maybe the composition of nutrients in the soil? I just don't know. But I think you maybe right.

I don't think I can blame the substrate as the soil should have plenty of nutrients and minerals for the plants no matter how much I soaked and drained it before setup. 

If that is the case, even if I fertilize and I don't plan to, it shouldn't make much of a difference.


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## AaronT (Apr 26, 2004)

K will always be a limiting factor in any soil setup with higher lighting.


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## bkhoshza (Aug 24, 2012)

Out of curiosity, do you know why that is?
I know plants absorb K a lot better through their leaves than their roots. Could this be one of the reasons?

I guess its just a matter of choosing which plants work better in soil tanks.

This was also an issue when I had a much lower light.

Thanks for all your responses.


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## AaronT (Apr 26, 2004)

I won't pretend to understand all of the science behind it, but yes that could be some of it (better absorption through leaves). I just know through my own observations that this has always been the case. When I setup a mineralized topsoil tank I put some KCL on the bottom for a potassium boost. 3-6 months later it's run out and I need to dose.


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## Woody0229 (Oct 29, 2012)

How long has the tank been set up? Do you dose anything to the water column?


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## bkhoshza (Aug 24, 2012)

The tank is now 3.5 months old. Nothing is dosed to the water column.

Since the light upgrade I have noticed an improvement but not a complete one. It may
be that I am using florescent tubes (T5) instead of spiral type. I have heard good things about spirals both here and other sources including the Walstad book.

It is just about half of the S.repens that shows K deficiencies, the other two plants (Ludwigia repens and Cryptocoryne x willisii) are doing fairly well so far.


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## AaronT (Apr 26, 2004)

Any reason why you haven't tried dosing K yet? I understand the idea of the NPT is minimal maintenance, but adding a few ppm of K at your weekly water change will only take a minute and will make a HUGE difference.


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## bkhoshza (Aug 24, 2012)

Hi Aaron,
I haven't tried dosing mostly because I never have and don't have much of a knowledge as to how really. I have started reading up to figure out how to dose properly as I don't want to throw the tank out of balance and also don't think I want to get into CO2 injections. Do you have any pointers as to where I should start with regards to minimal dosing?

Second reason may be that I am not a big fan of water changes and haven't done any for this tank since setup. I understand if I were to dose I would have to do some water changes. Would I be able to dose so minimally that my water changes don't require to be too frequent? I wouldn't mind doing a water change once a month or so.

What is your opinion on root tabs?


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## AaronT (Apr 26, 2004)

Root tabs would be a good way to go. 

You could use Seachem Flourish Potassium to dose about 3 ppm of K / week without water changes. Excess K doesn't really hurt anyhing.

Either of these ways won't require CO2 addition.


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## bkhoshza (Aug 24, 2012)

Thanks for your help and comments Aaron.


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