# Frogbit waffle pattern browning



## theatermusic87 (Jun 22, 2014)

Tagging along since mine look identical, if it makes any difference to the diagnosis I also have water lettuce in with the frogbit with no signs of deficiencyy, tank specs are roughly the same, just different ferts being dosed.


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## Archaeofish (Dec 18, 2014)

Good to know I'm not the only one! What is your dosing regime?


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## Zapins (Jan 7, 2006)

Can you do a nitrate test on the water?

Can you tank a close up photo of the plants or post a photo that is large so we can zoom in and see the damage up close? The photos you uploaded are very small and it is difficult to see the damage clearly. 

Also, these plants are floating plants and do not have access to the fertilizer tabs that you put into the substrate. This means they could be deficient in any nutrient that is not in the water column.


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## Archaeofish (Dec 18, 2014)

I figured that it would have less access to nutrients in the substrate--hence I started adding a bit of flourish to the water column. I wanted to be conservative and added about 2 ml per week. The tank is low-tech, set up pretty much according to the directions found here:

http://www.sudeepmandal.com/hobbies/planted-aquarium/low-tech-planted-tank-guide/

I have done several water changes, though (maybe 30% every two weeks or so) as I try to get the hang of balancing the fertilization and nutrient consumption. 

Nitrate has fluctuated a bit between 10 and 25 for most of the time the tank has been set up. Yesterday it was about 50 though (skipping KNO3 dosing this week), so that's not the limiting factor. 

My thinking was that this might have to do with the lights being so close, but others have shown pictures of frogbit getting a tiger-stripe coloration pattern in high light situations, which mine have not.


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## theatermusic87 (Jun 22, 2014)

Archaeofish said:


> Good to know I'm not the only one! What is your dosing regime?


2 tanks one 5g, one 25g

The 5g:
Gravel over miracle grow potting soil substrate. Established for 1.5 years. Gets a full does of flourish trace and a half dose of api leaf zone every week, 30-50% water change every 2 weeks, nitrates are always 0 as it's a shrimp only tank the bioload is very light for the amount of planting. Lighting is a finnex fugeray clip on light (4w LED 6" above surface of tank) and a HOB filter with the flow dialed way back.
Pictures:

















The 25g:
Pool filter sand substrate with seachem root tabs for heavy root feeders. Established for ~1 year. Gets a half does of flourish trace and a full dose of api leaf zone (started dosing this tank due to noticed deficiencies in stem plants which have gone away since dosing) with 30-50% water change every 2 weeks. Nitrates are currently barely above 0 (water change yesterday) but normally sit between 5 and 10. Lighting is a finnex planted plus (24w LED ~2 inches above surface) and filtration is a custom mattenfilter with spray bar, more surface agitation than than the 5g, but nothing excessive. Stocking is mainly tetras and other community fish, nothing that will nip at the roots.
Pictures:

















Both tanks also have some water lettuce and red root floater in with them, so they might show up in some of the pictures. As the waffle pattern progresses, it eventually dissolves that same pattern out of the leaf, before the rest of the leaf dies off. Most of the time but not always new growth is unaffected. 

Edit: thought I should add that the lighting duration is 8-12 hours timer is set for 8, sometimes i turn it on early, doesn't seem to really make a difference as far as increased algae growth.


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## Archaeofish (Dec 18, 2014)

Here are larger versions of those same images.


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## Zapins (Jan 7, 2006)

Very nice pictures. It is a macro deficiency, probably potassium deficiency but possibly nitrate or less likely phosphate. 

Increase the potassium dose to 25 ppm per week and see how the plants respond over the next two weeks or so. They should stop dying soon and start growing out normally if it is K deficiency.


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## Archaeofish (Dec 18, 2014)

Thanks for the advice. I have Equilibrium, which is 19.5% K, but it will also raise the GH because it contains divalent Ca and Mg. I've also heard you can get add potassium without Ca, Mg, or NO3 through potassium sulfate. Are there problems associated with high sulfate?


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## greaser84 (Feb 2, 2014)

I had the same problem in my 20 long tank, it is heavily planted, I was getting a lot of new growth on the frog bit but there was a good amount that were damaged just like yours. I doubled my K2SO4 dose and removed affected leaves and haven't had a problem since. Listen to Zapins guy knows what he's talking about.


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## theatermusic87 (Jun 22, 2014)

Zapins said:


> Very nice pictures. It is a macro deficiency, probably potassium deficiency but possibly nitrate or less likely phosphate.
> 
> Increase the potassium dose to 25 ppm per week and see how the plants respond over the next two weeks or so. They should stop dying soon and start growing out normally if it is K deficiency.


Thanks also for the advice, I added a second dose of leaf zone (potassium and iron) to both tanks and see how that goes. I think it's funny that was what you think it is, since I originally started dosing leaf zone because I had some chlorosis on some hygro, which i narrowed down to iron or potassium, started dosing and it went away... maybe i just need more of it


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## Zapins (Jan 7, 2006)

Thanks greaser84.

Adding K2SO4 is generally what people use to increase potassium. No the extra sulfur should not cause any harm. Most people have weekly doses of 20-30 ppm K using K2SO4.

You can use http://calc.petalphile.com/ to figure out how much to add to get the concentration you want.

To reach your target of 20.0 ppm K (from K2SO4) you will need to add 4.893 g K2SO4 to your 29.0 US, which is about 3/4 tsp per week. You can break up this dose into 3x 1/4 tsp if you like or dose once a week. The nutrient will not degrade in the water column.


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## Archaeofish (Dec 18, 2014)

Thanks so much. I'll look into getting some potassium sulfate. In the mean time, I added an equivalent K dose via equilibrium. By my calculations, doing this will only raise the GH by a max of 2 degrees (9 to 11). 

Thanks all. I'll try to remember to report back to help out anyone who has similar problems in the future.


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## theatermusic87 (Jun 22, 2014)

I hope you're having better luck Archaeofish than I am with my tanks. I am now experiencing quite the outbreak of black hair algae, in both tanks. My tanks usually maintain a backround algae population pretty much perpetually (usually green spot/diatom/green hair) and I leave it more or less alone as i like the natural look.

I added additional flourish trace (also a doubling of what i normally added) thinking something was out of balance and the black hair algae has exploded. The plants seem to all be exhibiting good growth all around, though i think the water lettuce is growing 2-3x faster than the frogbit. I'm going to wait the rest of the week out and see if it makes a difference, otherwise I'm going back to lower doses and separating the water lettuce and frogbit into different tanks.

I think the water lettuce is just sucking up too many nutrients, when i added it to my tanks originally is about when i started experiencing the deficiency


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## tamsin (Jan 12, 2011)

Floating plants have access to CO2 in the air so they tend to grow faster in low tech than other plants and react to a lack of nutrients quicker - some people use them as an indicator for when you need to add nutrients because of that. 

If your nitrate is zero you probably need to be adding a bit in.


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## Archaeofish (Dec 18, 2014)

Sorry to hear about your black hair algae problem. I've got a bit of it myself on slower growing leaves, and it seems to have increased slightly, but not so much that I mind. With the addition of the equilibrium (2 tsp per week) the frogbit seems to be responding fairly well. The brown spots are not all completely gone--partly because I didn't clip affected leaves unless the plants has more than 2 leaves--but I see fewer leaves with the waffle browning pattern. On a (possibly related) note, I'm also seeing some new growth in my dwarf sag, which hadn't done much at all for the first 6 weeks it has been in the tank. 

Is that the same as black hair algae the same as black brush algae? The bit that I have seems to cluster on the older or slower growing leaves. Some of it looks wiry and some of it more fuzzy. None of it looks like the tufts I've seen in pictures of black brush algae.


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## latchdan (Sep 7, 2007)

I've noticed my frogbit looks bad when I get too much water movement, this happens when I don't top off my tank due to evaporation and they get kicked around.

Also adding more potassium seemed to help mine a lot as well.


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## Zapins (Jan 7, 2006)

Any update on the plants with new pictures?


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## Archaeofish (Dec 18, 2014)

Yes, here is a picture. As you can see, things look a lot better. I had a lot of new growth, and the I started getting many more leaves per plant, rather than plants growing two leaves and then sending out a runner. My treatment was adding 2 tsp of equilibrium (a major component of which is potassium sulfate) per week for two weeks. Previously I had been dosing 1/4 tsp. On he third week, I brought the dose down a bit, as I was having a bit of algae--hair or staghorn maybe--though I'm not positive that the extra potassium was the reason for it. I also did some pruning and replanting that may have stirred the substrate a bit too much. 

It was nice to see such a clear and direct resolution to the issue. So many times (algae growth, fish sickness) it seems like it's hard to properly diagnose the problem and devise the correct response.


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## Zapins (Jan 7, 2006)

Equilibrium has: potassium sulfate, calcium sulfate, magnesium sulfate, ferrous sulfate, manganese sulfate in it. As you say mainly K2SO4. Of these nutrients only K and Mg are mobile nutrients (when deficient show damaged old leaves like your plants). So either one of these was likely deficient. Personally I think it was much more likely to be a K deficiency since K is used in huge amounts by plants, and you already had a GH of 179 ppm which likely means you had some Mg in the tank.

No way to know which one it was for sure though since both were added. At least the plants are looking great!


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## Archaeofish (Dec 18, 2014)

I agree with the potassium deficiency hypothesis. Gh is an indication of all divalent ions, most of which are going to be Ca and Mg. So a high Gh reading and an Mg deficiency is theoretically possible if all of it was due to Ca and other divalent ions, but it's highly unlikely. 

Thanks so much for the great advice!


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