The way you "backwash" a sealed pressure system sounds a lot like the way a munincipal water company filters a town's tap water. (I work for a water plant.)
It works like this... sand, anthricite, or some other similar media with the coarseness roughly of ground coffee is used. A bed of this sand will allow water to pass through while filtering out solids. These solids tend to clog up the sand reducing the flow, so periodically to clean the sand you just reverse the flow of water through the sand allowing this waste water to drain out of the system. Because the sand is heavier then the solids it's filtering, the sand will fall through the water current while the solids will be carried out of the sand & away. Looks kinda like using a gravel vac on an sandy bottom tank. Rate of flow obviously needs to be regulated for the backwash, or else even the sand can be carried away.
It's a good system generally, but requires a lot of space. Your sand bed needs to have enough surface area, or maybe I should say, a foot print, so that it doesn't clog up too fast. However, to do a decent backwash on that large of a foot print, you need to have a large pump capable of moving a large volume of water fast enough to carry the dirt away. Backwashing is easiest if it's automated. Otherwise, you need to keep a close eye on things or you could wash away the sand or drain your fish tank completely in a matter of a few minutes..
This is my first large salt water tank (150 gal)...i have it all set up with wet dry and protein skimmer. I have some live rocks and some damsals (8), the tank is going through the cycling process. I have noticed almost all my fish have died and the wet dry I constantly have to be putting in at least 2 gal of water a day.
My question is this...do I have to have the protein skimmer constanly on and do I have to put water in the sump daily to keep the water level where it suposed to be? Any help on this would be much appreciated. Temp is good on the tank. 80 degress
Once upon a time I had a 20 gallon tank with an undergravel filter. I took the output of the powerhead through a hose up to a rectangular water jug from Walmart (2.5 gal.). The jug contained red lava rock from Lowes. The jug sat on the back of this tank and against the wall. A hole in the bottom was over the tank. I had no worry about overflows on the floor. I imagine that anerobic bacteria may have lived inside the rocks. I did end up with a small amount of nitrates.
When I wanted to start a new tank, I could use some of the rock from this wet/dry filter to give the new tank a fast start. If you can live with the sight of a plastic bottle on the top of your aquarium, it could be a good thing. I know that it works.
I am overhauling a 150 gallon tank after a fight with Flukes that I surely must have finally won. I have a diy top that will conceal a 2 gallon container also from Walmart that I hope with do the job for this larger tank. We will see.
HI, I was wondering if you know anything about starting up a salt water tank? What I would like to do is have some fish and anenomes in the tank. Would you know the type of filtration I would need in order to get it started and what are the necessary tests that I would need in order to maintain the tank? Anything would help..thanks