Hygro red top - loosing lower leaves

[Larry Grenier]

I believe its Hygrophilia polysperma 'Rosaneruig' like on the startup page. It has growth on the tips but the lower leaves are mostly gone and roots are streaming to the bottom instead. I have a few florida flag fish that may be picking at them. I hardly feed the fish so they will eat the algae. What do you think I should check?

[krisw]

Do any of the leaves have brown or yellow spots on them before dying off? I've had that, and a little (I really do mean a little) Flourish has helped. Otherwise, how much light do you have on your tank? I've had pretty good luck with this plant in tanks with about 1.5Watt/gal and more. A lack of light could certainly explain why only the parts closest to the top are thriving.

[Larry Grenier]

Don't see much yellow or spots on the leaves. I just got over an algae war so I've been going light on the light (pun intended). I currently have just over 1.9 wpg but only for about 6 hours then much less. I do sparingly use Flourish liquid. My crypts seem to be doing fine along with a few other species of plants.<edited><editID>Larry Grenier</editID><editDate>38254.5559143519</editDate></edited>

[krisw]

Hmm... What other plants do you have in there? I would expect your crypt's to do okay, as they will often do well in low light. (Plus, they are root feeders. What kind of substrate do you have?)

What kind of algae have you been having? Something is definitely unbalanced. You should be able to keep the light on longer than 6 hours. Do you inject and CO2 into the tank?

[Larry Grenier]

SUBSTRATE: Lower 1.5" - Onyx Sand mixed with common sand. Upper 1.5" - Natural aquarium gravel a little Laterite around some plant's roots.

I have 2 of those hagen/nutrafin c02 things (lazy man's DIY c02).

Other plants: Anubias, Cabomba, Crypts, Italian Val, Ludwigia, Java Fern.

Everything is growing well. I have to regularly remove cabomba and val. The ludwigia also seems to be loosing lower leaves and some are yellow. The tank is 24" tall so maybe 1.9 wpg isn't enough.

[krisw]

On your algae issue. If you have laterite in the top 1.5" of your gravel, this could very well be leeching into the water, and be the cause of the algae blooms. If so, I would probably hold off on any Flourish for awhile.

For the Hygro, I would guess that it is a light thing. Whether it's that 6 hours isn't enough, or that the intensity isn't high enough, I'm not sure. I would think that you would want to try and get your lighting period up to 10-12 hours at least, which is seemingly hard to do without creating too much algae. In a perfect world, once the hygro and ludwigia took off, it would outcompete algae for nutrients. I'm assuming that you are doing regular water changes? (weekly/bi-weekly)

Does anyone else have any suggestions? Maybe adding a nutrient hog like riccia fluritans to help compete with the algae as Larry increases the light duration? I'm out of ideas.

[Ghazanfar Ghori]

Polysperma itself is a nutrient hog! Check your
macros - go for about 5ppm of NO3 and 0.5 ppm of PO4.
If you see pin holes in the older leaves of the hygro,
it could be a K deficiency. Hygro is one of the best
indicator plants for that IMO.