Hi . . . been round the fish sites and forums before. Have a 55 gal tank . . . had it for 12 yrs. Same power heads , filters, special gravel, etc. Currently have 2 parrot fish [one male, one female . . . lucked out with this one . . . are always laying eggs] Have one Jack dempsy, one p. algae eater. All fish are a good size . . . have had them all 6 / going on 7 yrs now. First set of fish was similar . . . had them for about 5 or 6 yrs . . . made the bad mistake [and I knew better] of putting son's one fish in tank without checking it. Wiped out tank.
In my second tank I have special gravel . . . [do not know name of it . . . got it with tank] that removes all nitrates, ammonia, etc. so I was told then and seems to be the case.
In my filters I use dark round sponges [that are I suppose filters for something else . . . got them at petsmart and thought would be a good filtering substrate instead of buying those cartridges all the time] and add carbon. Rinse them out on weekly basis. I do 1/4 water changes weekly and sweep gravel weekly. I clean power heads, entire filters probably once a month. I add uniodized salt to tank [very small amount] once in great great while. I also add water conditioners once in great while. No underground filter . . . don't believe in them. No air stones . . . power heads are way to go. The less cost to keep tank going the better.
My fish are happy . . . I am happy. Looking for a bigger tank one day. Got mine [55 gal.] . . . all set up with stand, filters, powerheads, gravel, etc for 125.00 in paper.
Hope we all have great chats together and we learn lots of stuff together!!!