What is this crypt deficient in?

So I’ve got this one huge crypt in my 29 gal. Not sure what kind he is.

I fertilize with flourish (comprehensive, not excel) and osmocote root tabs, which seem to work pretty well. However, about every 1-1.5 months this crypt begins to melt. Once I add more root tabs, it stops melting. I’ve been trying to make it a habit of putting a root tab under him every singe month to prevent the melting, but that is a lot of root tabs. With all my other plants I can go like 3 months on the root tabs.

There is some sort of deficiency in this crypt of something that is only in the root tabs. And I don’t think the root tabs have enough of it, they just help a lot.

What type of deficiency causes melting in crypts? Mostly just little holes getting melted into his leaves, sometimes if I go too long without giving him a tab, a couple whole leaves will melt off. I’m not sure what it is, and I’m trying to fix the deficiency so I don’t keep having to give him like 1-2 root tabs every month to keep him from melting.

I’ll try and get some pictures of what the melting looks like in its more minor stages. I gave him a root tab a few days ago, so it’s healing now.

 

Sounds like a potassium deficiency.

Usually, it enters the tank from fish food, but that's not enough for a lot of plants. I'd say find a specific potassium fertilizer. The comprehensive probably isn't supplying enough, especially if your tap water has very little.

 

Yeah, I did a little research and it does look like a potassium deficiency. My anubias also looks potassium deficient (older leaves turning yellow and brown at the tips).

I'm thinking maybe trying some API leaf zone? that is just iron and potassium. I've never used any API ferts before though, so I'm slightly skeptical.

 

Yeah, I did a little research and it does look like a potassium deficiency. My anubias also looks potassium deficient (older leaves turning yellow and brown at the tips).

I'm thinking maybe trying some API leaf zone? that is just iron and potassium. I've never used any API ferts before though, so I'm slightly skeptical.

I don't like fertilizers like that no, especially if it is potassium and iron. Mainly because iron is a micronutrient and potassium is a macronutrient. It sounds like an algae bloom waiting to happen.

I would recommend
Seachem Flourish Potassium
https://www.amazon.com/Seachem-67104660-Flourish-Potassium-250ml/dp/B0002A5WRY/

That way you can just worry about the potassium. Iron leads to hair algae quickly, I've never had success tinkering with it.

 

Flourish potassium is just twice as expensive...

 

Flourish potassium is just twice as expensive...

Your move then.

 

Guess I’ll give the leaf zone a shot. I’ll start at a half dose and see what happens. If I get an algae bloom I can try a pure potassium supplement.

 

Potassium is potassium lol, why are you afraid of leaf zone?

Just so you know, potassium is the one nutrient that won't contribute to algae whatsoever

I like to dose a bit of extra potassium in all my tanks from time to time, it's good practice

 

Potassium is potassium lol, why are you afraid of leaf zone?

Just so you know, potassium is the one nutrient that won't contribute to algae whatsoever

I like to dose a bit of extra potassium in all my tanks from time to time, it's good practice

It’s the iron. Leaf zone has iron in it as well. That’s what might cause algae.

 

It’s the iron. Leaf zone has iron in it as well. That’s what might cause algae.

You'll be fine

 

Would like to point out that as someone with both flourish potassium and Leaf Zone that flourish has a higher concentration of potassium, maybe enough to justify the higher price tag

 

So, update. I used the leaf zone. I did an algae bloom, but I also went out of town and got a small ammonia spike while I was gone and that might’ve been the cause of the algae.

I haven’t really notice any difference in the crypts yet, but my rotala went crazy! The rotala and the vals have both been going through a growth spurt. Both of those plants love iron as well, so that might be playing a role in it too.

The giant duckweed on the other hand actually slowed in growth. Usually I remove half of it every week and by the next weekly waterchange it’s already covered the surface again. Now it’s just kind of lingering. Maybe the happy rotala is taking up more of the nutrients now or something.