Lilaeopsis thinning out

[B Considine]

Just over a year ago, I set up a mineralized substrate 65 gallon aquarium using Lilaeopsis brasiliensis (my guess as species wasn't listed) as my foreground. After a period of strong growth, it has begun to thin out, especially in the center of the tank. It is still growing (not as strongly) along the sides. What started as luxurious growth now needs a toupee.

I've got a Catalina T5HO fixture, currently dose Excel daily, and do not add any other ferts. I do a 20-30% water change weekly, as schedule allows.

Any explanation/remedies for the poor performance of the Lilaeopsis when my other plants are doing just fine?

Blaise

[Aaron]

Is it yellowing as well? It may be you need to dose a little potassium now that the original potash has run out.

[B Considine]

No, not yellowing. Just getting smaller and smaller. The thick areas don't seem to be sending out runners anymore, either.

Blaise

[Aaron]

Even so I suspect potassium deficiency. Try dosing about 0.1 ppm / day and see if things don't turn around in a week or so.

[SCMurphy]

Pull up the thin section and replant. It sounds like you have an anoxic spot that needs a little turning over. The process of pulling up and replanting will both aerate* the substrate a bit and spur the Lilaeopsis into a growth spurt. Make sure you do it the right way and cut up the runners into individual plants.

* No, it's not "hydrate" even if it is underwater, because we are trying to get some O2 into the substrate, not water.

[B Considine]

I don't think it's an anoxic zone, as crypt runners pop up regularly. Also, the "thin zone" is probably 6" x 6", which seems big for a dead spot.

However, I'll give it a poke and see what bubbles up.

Blaise

[SCMurphy]

Crypts can overcome anoxic where Lilaeopsis will just die back. You may not get bubbling when you disturb the sediments.

[B Considine]

Did not know that.

Should I both replant and dose potassium?

[SCMurphy]

Sure.