frankly i dont know why anyone would want to set up a system that means they have to do so many water changes. changing out water so often is a real drag. for me the ability to go on a holiday is taken into account when setting up any system so that means either no siphon or water change for days or an auto timer, mind you relying on techno gear is hit and miss so i try keep it simple and use water flow and settlement to make it easier.
a system that removes uneaten waste and fecal matter out of the tank instead of leaving it in the water will go a long way to reducing your overall load. a conical settlement chamber can be fitted prior to the pump, imagine a fuel funnel with an inflow into the side near the top and an outflow on the other side and a tap on the bottom. this will create a dead spot that stuff will fall to. maybe google swirl seperator for a picture.
so that way the garbage dosent get smashed up into smaller solids making them suspended solids. i run 3 of these that are 400 litres each in a big shed tank system with above flow from the main pump through bioballs and lower side flow coming from the middle base of the recirc tanks. youd be amazed at how much junk i can tap off..if i didnt do that it would be loading up my water.
have a tap on the base of that conical tank so you can drop the garbage out. then from the pump to the biofilter place a 10 micron mesh bag above filter balls on a pvc tray with holes drilled into it that you can swap out as it begins to block, i use 60 micron polyester sheeting on my big system cause 10 micron is too fine for that much feeding. this will pull out lots of finer stuff. set it up in a way that if it blocks water it will still flow over into your drip dispersal tray. ie make sure it sits under the tank lip and well on the inside of your drip tray. your drip tray should have sides siliconed on so you get an even flow through your drilled holes over your bioballs.
this means you bioballs get washed by gravity instead of clogging as in the case of them being submerged. you want no spots that hold old food or poo so this means no sandy or rock type substrates on the bottom of the tank.
if you have decent surface area on the biofilter you should atleast get no ammonia troubles, so your probably got a heap of fine suspended particles or maybe feed tannins making your water look unclear.
maybe have some small air plants like lettuce under the lighting sucking up nitrates and other dissolved nutrient salts. i send my changed out water to culture algae in an outdoor pond. i do a change once a week. that way the nutrient is used up recycled but a submerged tray of filamentous type algae plant that you can harvest out as it grows bigger is a good idea. all that said nothing beats a big water storage tank.
