Crinum confusion

[Jess]

Ok, smart folks - anyone have advice about my crinums?

45-gallon tank with "Platinum" aquasoil (the one NilocG sells); parameters now are pH 6.4, KH <40 ppm, GH (honestly have no idea - I have so much trouble matching up this color), nitrates 25 ppm, nitrites and ammonia 0 ppm.

I got these crinums from the co-op in June 2021, and until two weeks ago they looked and grew absolutely fabulously.  I think I set up this tank last Spring.  I haven't moved them or anything, and I don't think I've added any root tabs (though I'm not 100% sure).  Suddenly, in the last two weeks the leaves have started melting halfway up the stem, kind of near the tank surface.  No major changes in the water that I can think of.  This tank had CO2 in Dec-March, but that's it.  It has BBA that I've fought for awhile.  

Any clue why my crinums are melting like this?  I've now lost every leaf of one of my two crinums - parts of leaves measure up to 2ft each.  So this plant will never look the same.  My tank is 24" high so the length of these was really beautiful.  I ordered two more from Co-op and they came last week but just bulbs, no leaves at all, so it will take a few years for them to grow long and beautiful.  In the meantime, I'd like to figure out what's going on and possibly prefer further melting but definitely to make sure my new plants have the best chance of survival.

Thoughts?

Pics - sorry they got turned upside-down - but trying to highlight how they just develop a small big of brown melt/rot and then the leaf breaks off.  Plant got too hungry maybe? 

  

Edited September 27, 2022 by Jess
typo

[Fish Folk]

Three things to consider:

(1) In my view, Crinum appreciate Root Tabs. This is also recommended by the CoOp on their Crinum sale page here.

(2) With a very tall aquarium, your overhead lighting needs to be unobstructed. If your floaters are multiplying too much, it is possible that your Crinum is missing out on needed light.

(3) [On this point I defer to my betters] Crinum may be susceptible to death-by-damage. If they are kinked / bent, they may die from that point forward. If you have anything that might cause that, this could be a consideration.

Edited September 28, 2022 by Fish Folk

[Jess]

Thanks!!  Yeah I think I will put a root tab under each...I kind of have some confusion because I have aquasoil which I thought meant I don't need root tabs (until the aquasoil gets depleted, which I thought would take quite a bit longer than a year).  

Keeping my floaters in check is definitely a challenge...I need them for some of my fish (halfbeaks that are really territorial; there's no info about them online so I didn't know what to expect but they definitely stake territories), but they definitely also block light.  My crinums are conveniently situated right near by air bubbler though, so they probably get the most light since the turbulent waters keep the floaters away.

death-by-damage - a very interesting idea!!!  It's weird...just some random spot turns brown and melts, and it doesn't look particularly damaged.  The only thing the spots all have in common is they're all relatively close to the water line.  It kind of looks like the plan is trying to conserve resources...I'm gonna add some root tabs ASAP.  Luckily I just bought some from the Co-op! I think I'll go with those and get rid of the rest of my Flourish tabs (they're super old, from the last time I kept aquariums which was early 2000s, and I've used all but 3-4 of them and notice no difference in the plant health for things like my lilies and crypts).