[Bert H]

My L. repens is developing brown spots which eventually turn into holes on older leaves. Any ideas on cause/fix are welcome. No other plant in the tank is affected this way (sag, anubias, A. reinickii, bacopa, R. indica and C. wendtii).

Tank Parameters: 29 gal tank; I keep NO3 at approx 10, PO4 about 1 ppm. KH is 9.5; K2SO4 added at water changes (50% weekly); CO2 25-30ppm; Fe dosed daily between 1/4 and 1/2ml. Traces added 2X a week 2ml of flourish.

Thanks for any advice.

Bert.

 

[MiamiAG]

Bert,

As you may know, holes in leaves is typically a symptom of K deficiency. Based on your dosing regimen, I assume that you should have plenty of K in the water. This means that something may be blocking K or you have it at toxic levels.

You didn't mention your GH. Do you have a measurement for that? Also, your KH seems a bit on the high side. Is that as part of your tap?

 

[Bert H]

We have well water and, though very good, it is hard. My gh is 11.5; kh is 9.5. I dose 1/4tsp of K2SO4 weekly with 50% water changes. Does high gh/kh interfere with K uptake? As I said, however, this situation doesn't manifest itself with any of my other plants.

 

[MiamiAG]

Bert,

Lets make sure you don't have a snail or pleco that likes your repens, right?

Interference, particularly between calcium and potassium, is controversial. I think because it is so difficult to prove or to rule out something else. I think the best thing to do is reset your tank by doing several large water changes.

See if that resolves the problem. Give it a few weeks. If not, we can try to play with your nutrient inputs. I don't think your inputs are off so don't want to change that now.

Oh, one last thing, can you figure out the calcium portion of your GH?

 

[Bert H]

I hadn't thought about the snail angle. I do have snails, and it would be impossible to get rid of them short of getting something that eats them and I am not sure they would be compatible with the other fish in the tank. Oh, well...

There are no plecos in the tank. My algae crew consists of 2 ottos, 1 sae, and a bunch of shrimp. I don't have a way to measure Ca.

I will just live with a few holes in the repens, since all else is going well! 8) It's funny, about 18 months ago, when all I could grow was hornwort, I wouldn't have cared if I had any holes in anything else, just that it would grow! Funny, how human nature can be.

 

[MiamiAG]

If you have too many snails, place a plate on the aquarium bottom with a food tablet overnight. The next morning, they would have congregated on the plate. Just remove the plate.

Let us know if the holes get worse or if they progress to the stems.