Join Date: Nov 2007
Location: NYC & Long Island, NY
You have a lot of light for a tank with a gravel substrate, DIY CO2, and no macro dosing.
What Id suggest, unfortunately, is less light. You have a very long photoperiod, no macro dosing, an inert substrate, and very low CO2. Your light is throwing off the balance. A shorter photoperiod, and ideally a weaker bulb, will lead to slower growth, and hopefully fewer deficiencies in your plants.
If you want to keep your light, Id start saving up for pressurized CO2. You're never going to be able to maintain even 20ppm CO2 with DIY, unless you're planning on setting up gallons of DIY solution, in which case pressurized will be cheaper anyway. Also, you're not dosing macros, and you may want to consider that as well.
Short term fix? Maybe try some root tabs to throw under the swords in particular. They're heavy root feeders, and your gravel and Flourish may not be doing it for them. Swords also like lots of iron, which may be one of many reasons for weak yellow growth. Try iron. Then figure out your CO2 and macro issues.