yes, i agree that is a very nice tank stand. and i think you may have algae and not allergy, if you had allergy you would not be able to get close to the tank w/out sneezing your shoes off.
you may want to try a phosphate remover if you dont have a fuge w/ macro algae and perhaps invest in a diatomacious earth filter ( DE filter ) do a water change, then stur up the water alot along w/ the substrate, run the filter for a couple of hours, pull up a chair and read a few magazines next to the filter as they clog fast depending on how bad your tank is, if the filter starts making noise or if it has a pressure gauge on it, dont let it over pressure, this is a great filter , costly but great, i used to clean pools and these are the type of filters i commonly used, you can get smaller ones for fish tanks, DE is a fine powder, it gets pressed up against a fine synthetic mesh which creates a filter wall down to a few microns. never get this powder in your tank as it will turn the water milky white and you will have a horrific time reversing this, keep media in the filter bag or as instructed by filter manufacture. DO NOT run this filter w/out supervision, dont leave it on all day, because they filter particles so small they clog faster and can become damaged.
and remove the sponges from your tank, go to pets mart and somewhere where they have all the filter media and such for fishtank filters, look for 1' x 1' bag of blue or white fluffy stuff, this is a roll of mechanical filter stuff, its a long sheet (about 4 foot long ) of it thats been folded into a roll, i think its the same material they use to fill cheap pillows, like poliester but stays together better, this is real cheap stuff, i got some for only 2 bucks, just cut to the size of your sponge that you where using, you might have to attach it to something like non metal screen w/ large holes so that the filter doesnt fall all over the place. here are some pics of what i use, i got it at petsmart and how i have it set up, i have a cheap filter for a 20 gallon tank, i dont recall the brand but its cheap w/ this plastic thing in it, my other filter i replaced all media and only have ceramic rings in it for biologics and its an avg. HOT filter, just w/ ceramic in it.