Sword wasting away

[cplawrence]

I have a 75 gallon with 130W PC lighting. The tank has been going for almost three years now (planted for about 2.5). I have some amazon swords which had been doing wonderfully for some time, but now are wasting away. At first, I was concerned that they were being starved for light by an overgrown wisteria. A couple of weeks ago, I trimmed it way back in the part of the tank that has the swords, but they seem to be doing worse.
My thoughts are either fertilizing or light. I switched to a modified EI fertilizing approach. I have been doing 1/2 teaspoon of nitrate, 1/8 teaspoon of phosphate, and 1/4 teaspoon of plantex per week. I scaled back to those levels when at some point my fish did not seem to be doing all that well. My nitrate test indicated that it was through the roof, but the 1/2 teaspoon seems to be keeping it to more reasonable levels (20+ ppm range). When the plant damage first showed up, it seemed to low potassium (holes forming in the leaves). I now have my potassium dosing up to 2 teaspoons every other day. Recently, I have been seeing more and more of the leaves turning brown and wasting away. Carbon has been provided using Excel.
As for lighting, as I indicated the tank has been planted for 2 and a half years and for some time the swords were doing great. I have not changed the bulbs during that time as I was under the impression that it was not necessary to change PC bulbs until they burn out. Is that impression incorrect and should they be changed?
Thanks as always,
Chris

 

[An t-iasg]

Swords are heavy root feeders. Try putting some root tabs under the swords. The root tabs should help even if you have a nutrient-rich substrate.

PC bulbs should be changed before they burn out. I have read to change them anywhere from 8 months to a year. I remember that I started getting algae at about 10 months in my tank, so I changed the bulb and that seemed to help. Even if you're not getting algae, the light spectrum is not the same as it was when the bulbs were new, so the plants could be affected.

Some plants are reported to be adversely affected by Excel, but I don't think swords are one of them. Your tank is under the threshhold for CO2, but you must go through Excel pretty quickly on a tank that size.

 

[cplawrence]

OK--I have the stuff to make up some root tabs so I will try that and I will go ahead and replace the bulbs in there. Yeah, I do go through a fair bit of excel, but I do dose a bit less than I would in a higher light tank. In the long run, pressurized would still be cheaper and it is on my agenda to do someday.

I appreciate the advice and happy Easter.
Chris

 

[An t-iasg]

Happy Easter to you! I have two not-quite-medium light, 10 gallon tanks and I have pressurized CO2 in them. I also base my fert dosing from EI. I use the amounts that the EI table says to use for a 10-20 gallon tank. I cut that amount down a bit and I dose twice a week instead of 3 times. It's working out great! Pressurized CO2 is very nice to have no matter what your light levels. If you had pressurized, you could have the ability to make the tank higher light someday too.

 

[Purrbox]

One other thing with swords is that they can go into a dormant phase. If you uproot them you may find a sort of bulb at the base of the roots. By breaking this off you can plant to grow a new plant from the bulb and revive the original plant by forcing it out of dormancy.

Unfortunately I don't remember all of the technical terms for this. If you have a chance to pick up a DVD from the 2006 AGA Convention, Dorothy Reimer had an excellant presentation which covered this topic.

 

[gu2high]

My Amazon sword was dying too, all leaves were rotten. My pc bulb is 1 year and 4 months old. I used Flurish Comprehensive. I almost wanted to get rid of it.

However, after I used Excel, within one week, to my surprise, new leaves came out. In 3 weeks, it looks like a new, very healthy plant. Nothing I have changed. Only change is, I added Excel at 80% of recommended dose.