What am I doing wrong?

Well, since someone took the time to make this topic section, I figured I may as well use it.
First of all, any idea what this is? I believe it is some kind of sword but I don't know for sure. I should but I just grabbed them when I was getting fish because they looked neat. Sort of a "and give me a couple of those things" type decision.



But more importantly, these plants don't look too healthy. The older outer leaves keep getting these small necrotic blotches and eventually die off. It normally progresses from the older leaves inwards.



When I re-did my tank recently, I pulled off all the dead and dying leaves but now I see that the next set of leaves is starting to turn. Is it lack of light? The tank lights were on from 2pm to 11pm daily but after reading one of Klaus' posts, I upped the light to a full 12 hours, noon to midnight. The roots are healthy but the leaves get ugly. They haven't outright died yet but they aren't flourishing.
Any thoughts?

Swords are heavy feeders and take some of their nutrients through their roots. (Iron being an important component) I would recommend buying a name brand substrate designed for plants. Not only does it provide nutrients but are of proper grain size to insure adequate water circulation. I would also try doing daily doses of liquid fertilizer also available for aquarium plants. This method works very well but you must do very large water changes once a week to prevent an algae outbreak.

Lighting is a subject that a thick book could be written about. Suffice to say that a bulb in the 6500k range that provides 3-4 watts per gallon in the tank will do nicely. In the wild these plants only get at a maximum 10 hours per day of light but it's very intense. With lower wattage say 1-3 you'll want to extend the period of time they are on. You might also look into metal halides as these, in the long run, provide the best bang for the buck in lighting because of their longevity.

For right now I would try the dosing method with a name brand liquid fertilizer that also provides Co2 in some form.

Well, if they are heavy feeders that would explain the necrotic patterning on the older leaves. Classic Sink/Source scenario where the plant is robbing older leaves to feed new growth.
Thing is, this isn't a planted tank and I just changed out all the substrate so I am not excited about doing it again. I will try the nutrient suggestion but if I have to fight algae constantly, then it will likely become an unplanted tank. The lights are 10,000K compact flourescent but I do know they lose their intensity with time. I believe they are 55 watts each. That would only be about 1 watt per gallon on a 90 gal tank. Would increasing the wattage help? Other plants that I've had in the tank didn't do well either.

I appreciate the advice and I'm not ignoring it but it seems like more than I want to do at this stage to save two plants. I fought algae before with other tanks and I would rather not do it again.

I am curious about your comment regarding the grain size. I had gravel in before and now I've switched to sand. Is the proper pore somewhere in between? Depending on what the substrate is, I may consider getting a little bit and putting it in a small, shallow container and then putting the plant in that and covering the edges with sand but I don't want to go through taking it all out again.
Thank you very much for the advice though.
Graham

A very cource grain sand is recommended. But it also must be ammended with some clay with the addition of an iron rich additive. Basicaaly its a powdered mud from the weathered hills of South America. Isolating an area for just the plant would save a lot of work and be less expensive to do.

If the tank was more heavily planted it would out-compete the algae. The hardest part is getting them established. Algae is oppurtunistic and can spread rapidly but a well established planted tank can soak up the nutrients quicker.

Chances are if you have a lot of Mbuna in there most plants won't last long anyway. You might try Anubias or Java fern. Both seem to do well even around herbivores and are low light plants.

I've tried every live plant I can get my hands on and none last more than a week or two in my Malawi tank... they just rip them to shreds... I found a guy on ebay that has VERY realistic looking plants. Obviously you don't get the benefits of a live plant with them, but they always look nice.

ebay seller name is discountaquatic

I've been very surprised that these plants haven't been eaten at all, there are probably 20 juvenile mbuna in there and although they may occasionally try to nibble some algae off the leaves, they haven't touched them otherwise.

I have had lunch with plant, but never much with swords. I think my watts per gal have always been too low, <2wpg. Also, as mentioned before require lots of iron.