my water parm's are great never a nitrate issue, the wet dry filters i only use are TOM wet/dry filter and they only make 1 model often you can find them on sale at dr fosters or thatpetplace or bigals web sites. you get everything in the box and there is nothing else to buy its plug and play when you open the box. over flox box and return pump is all included sweet filter great company TOM. i run a hot magnum with the micron cart to polish the water. i make my own filter pads for the wet dry filters so cost there is almost nil. i been running some of them for over a year now and have never had water quality issues the top basket i have poly filter pads the next 2 baskets i have full of coralife nano bio balls you can use regular size bio balls in them i just happed to have a huge black plastic garbage bag of the nano bio balls i got for free from a friend who moved so i just used them. the baskets that hold your media choices are large and deep and hold alot. and the top of the wet dry is enclosed its not a open top which helps with evaporation.