What causes Freshwater Plant Meltdown?


Lifetime Charter Member
Lifetime Member
Jan 3, 2006
San Francisco East Bay Area
What causes "meltdown" of freshwater plants?

Has anyone ever studied this often reported "experience" or tried to/succeeding in replicating it in the lab? What factors or triggers or common conditions were observed?

Has this phenomenon been covered in a past Barr Report?

Background Info:
I have had more than a few Crypto's wendtii "crash" on me. I've also had one Hygrophila corymbosa 'compacta' "melt." Yesterday I had a stand of Ludwigia arcuata collapse as well. In each case, these were isolated plants that wilted away overnight/in one day. No other plants were affected.

In none of these cases did either of us note any obvious nutrient deficiency signs before the crash (2 sets of planted tank keeper eyes). Some tanks were not CO2-injected. All were regularly dosed with other ferts.

The tanks substrate in each case was standard gravel (pea, Eco-Complete) or RedSea "clay" nodules, and the tanks were all well established with a good number of thriving plants [NOTE: I've never had a plant melt in any tank with the SeaChem (Red) chip gravel.].

All tanks were well lighted (2.5-5 WPG).

I look forward to your answers or additional questions/feedback. Thanks!


Lifetime Charter Member
Lifetime Member
Jan 24, 2005
Re: What causes Freshwater Plant Meltdown?

I've read a bit about crypt meltdown. Supposedly it is caused by a change in lighting-substrate-water chemistry or whatever. And it does happen.

But a few weeks ago I moved two C. wendtii plants from a low-tech, soil based tank to a water column-dosed tank with plain gravel, and they are growing faster in the new tank than they did in the former one. Lighting and water are about the same. I did add two Seachem plant tabs at the roots of the crypts.

The H. polysperma that I moved at the same time aren't doing nearly as well.

In this hobby there are always exceptions to accepted truths.



Lifetime Members
Lifetime Member
Aug 25, 2006
Peoria, IL USA
Re: What causes Freshwater Plant Meltdown?

I just had the majority of the twisted Val in my tank meltdown. For one..I think it knew I was going to thin it out and sell it at our fish auction...but I had someone suggest that is was from dosing Excel. I've been dosing Excel for the past year...I don't think it's that. ANy ideas?