[The old man]

I been into planted tanks for a about a year now and here is a brief summary of my experience. Plants and fish require different things. Plants love C02 and Fish do not. Fish love Oxygen and plants do not. Fish usually love algea and plants do not. So, in order to have both healthy you must have a balance.
I only use excel at this time and both are doing well. It helps control algea a bit and plants love it. A twenty gallon tank should not be to expensive until you get things under control then you can go to diy or pressurized if you see the need. Feed the water column with a line of liguid ferts (seachem, etc.) for awhile and see if it helps. I'd recommend using Flourish, nitrogen, potassium, Iron and maybe just a minimal dose of phosphates. You should not need the Trace. Get a few ottos, a couple bristlenosed cats (small) and about 3 corys to help with the algea and keeping the gravel cleaner. Some plants will inhibit the growth of algea also, such as hornwort and other fast growing plants. Keep up the tabs on the Sword and do partial water changes. Would like to know what fish you do have and your light watts and bulb type. You'll get it right just stick with it.

 

[The old man]

jazzlvr123 I agree about the corys, but he does need some to keep the gravel cleaner from the food on the bottom rotting and perhaps causing some of his algea problems. Maybe plants don't love oxygen, but what I was trying to say was that their requirements are opposite and a balance is needed.
After seeing his gravel and knowing he has about 34 watts of older bulbs which is probably to low light for the plants he wants. Also looks like he has an airstone or something adding oxygen which will probably lower his C02.
I agree with no salt. The fish you have certainly don't need it and all catfish I know don't like it.
I have Mollies and Swordtails and they are quite healthy and prolific without it.