Currently I am running two 7 inch dia filter socks in the Brute sump, and another one in the 30g pump chamber, so the water gets filtered going into the brute and out of it as well.
But today it got a DIY moving bed sand filter.
I was running a store bought sand filter a while back, but it had failures due to exposure to the sun, and so I decided this time I would hide my filter inside the Brute.
Because the entire thing (except for the electrical plug) is underwater, I don’t have to worry about leakage. I used press fit drip Irrigation fittings and pipe & if they drip a little bit it won’t matter. They were cheap and easy to put together requiring no glue.
Here’s the sand filter standing up on the edge of the sump, so you can actually see it. The pump is running and the sand churns up about 3 inches.
This has a two chamber design with a baffle in the middle. The water enters through a pipe that goes all the way to the bottom of the sand and the water flows out from a simple elbow fitting glued into the top.
Here is the sand filter under water in the sump. The pump is invisible at the bottom of the sump, below the filter socks. This helps draw water to the bottom of the sump.
I know it’s pretty impossible to tell what’s going on in that photo. The two flex hoses come from my 125 and 55 gallon tanks and they overflow directly into these big filter socks. The socks are just held in place with some zip ties and a piece of plastic tubing.
The three-quarter inch black tubing is poly propylene irrigation drip line. I used a little push on valve so I could control the flow and not blow excess sand into my filter sock. The smaller clear vinyl tube is the outflow from the sand filter and it goes into the left filter sock.
Having the entire system contained within the brute filter and completely underwater has other advantages besides containment of any drips.
Because there is no head pressure in the system anywhere when the pump is off, you do not have to worry about sand backing up into the pump should the system shut off. I turned it on and off several times and it starts right back up.
The other thing is that, should a hose pop off, the worst thing that can happen is that sand can wind up in the bottom of my Brute, And in the pump chamber filter sock.
If the hoses were external to the Brute, and one popped off at midnight, the system would blow 100 gallons of water out onto the ground before I woke up in the morning.
The sand I used was aragonite sand that I bought previously for my Cichlid tank, but I found that they like to dig it up way too much.
The two sand chambers are snack containers from the grocery store. It just so happens that the lids fit perfectly with a 4 inch sink strainer rubber washer and I used three of them to seal the system. There is a rubber washer between each cap and chamber and there was another rubber washer between the two caps which are back to back.
Those caps are clamped together inside by a 1.5 inch bulkhead fitting, which serves to baffle the chambers but still allow plenty of water flow. The blow tube is ordinary three-quarter inch drip irrigation pipe and I used epoxy putty to glue the roughened fittings into roughened holes in the PETE plastic snack containers.
I used Otey plumbers epoxy putty to hold the fittings. I have used this before on filters, but it tends to degrade after about five years under water. This may be due to something in the feed as I noticed it also turning a pink color, perhaps from the dye used in cheap fish food.
I know it will take a while for the sand to cycle in and although it is not brand new It has been out of the tank for months. Anyhow the system is running well I am hoping that it will improve things once it aGes. I did not take pictures of the construction, And I did not describe every part of it because I don’t attend this to be a how-to. I have tested the snack containers and they will take considerable pressure but the cap itself is the weak link.
One of these things could blow up in your face. They are strong but they don’t have the same quality control as a pressure vessel.
