Disaster (Kind of)

[Paul B]

For a couple of months my Reverse Under Gravel Filter has been backing up and I wasn't sure why.
I found out. I took a mirror and looked into the manifold that has three acrylic tubes coming out the bottom that feed the Reverse UG filter. That is fed by the algae scrubber screen on the right.
Water was filling the manifold which isn't good.
The reverse UG filter has been running for about 38 years and I don't remember ever cleaning the tubes but I could have in the 90s.

I saw that the tubes were completely filled with hard tubes and other growth preventing water flow.
I removed the clear manifold and noticed that one of the 1" tubes was loose.
I saw that it came apart right in the middle of the tank behind most of the rock structure with all the largest, oldest montipora and other corals.

I didn't really want to break them so while my fireclown was trying to sever off my hand I removed some large rocks in the back as well as a big bottle and other things I didn't know was in there.
(I can't see the back of my tank because it is built into a wall in a closet under stairs.)I managed to remove that part of the tube that went to the manifold so I could chop out the growth.

It seems when I built this I didn't install that tube in one piece, but instead I "spliced" it together with a piece of flexible hose which turned into glass in 38 years so it is brittle and came apart.

I managed to stick it back together and I made a "Rotor Router" snake to clean out the hard growth in the other two tubes and I pumped down water to push the rubble under the gravel.

I put everything back and all seems well. I would like it to run at least another 4 years. At that time the tank will be fifty years old and I may take it down. I am not exactly 20 years old any more and I travel more now and I know some day (hopefully not soon) I will croak and I don't want to leave this to anyone. I would like to donate it to someone who will know how to run it the way it is running which is different than most tanks.

 

[diana a]

Oh wow! Beautiful tank btw

 

[Mark Shelly]

I was working on a project that required a special sewage filtration system called an amphidrome that made me think of your tank. This system is used in Pinelands areas in NJ where they don't want to release phosphates and nitrates into the sandy soil where water tables can be pretty high. This system has a biological media canister in the middle. Sometimes the effluent passes top down and sometimes bottom up. This gives anaerobic and aerobic conditions in the media at different times. The appropriate bacteria work at the appropriate time. Aerobic back flow is aided with the pumping of air into the media (and possibly into the holding tank after the canister). It has a the vent that I assume is to allow the nitrogen and air out. The backflow also acts like a pool backflush by returning particles back to the first septic tank. What baffles me is how it brakes down the phosphates: I didn't know bacteria did. Does anaerobic bacteria, aerobic break down phosphates? I was wondering if it might be possible to convert a canister filter to do the same; reverse the flow on a timer that then sucked in a small amount of air only in that direction. The backflow could possible go back into a protein skimmer and from the return of a skimmer. This would probably only be practical if it was a water level due to the vent, although the vent could possibly be tied into the vacuum side air line for the reverse flow cycle. I didn't see any carbon source for the bacteria. Maybe it is in the media. And I don't know how often the media needs to be changed, if at all.

If, or when, you do break down your tank, I would be curious to see if mulm, worms or other solid materials have filled the space under your filter. Do you avoid this be filtering out the water before in goes into the under gravel filter? Do you have to clean out underneath, and if so, how? Is this space extra large?

p.s. I love your writing style.

 

[Paul B]

Thank you Diana

I was working on a project that required a special sewage filtration system called an amphidrome that made me think of your tank.

A lot of people think of my tank when discussing sewage.

I removed the UG plates many years ago mainly to see what was living under there. It was not filled with too much solid material, but it was filled with those tiny red feather dusters which are great filter feeders. Of course it also had plenty of detritus. I can see through the glass under the tank and I can see trails of worms and maybe tiny snails but it is not filled.
For many years I filtered the water going under there through a sponge, but I haven't done that in a few years as I just got tired of cleaning the sponge. Now there is just a strainer.
I don't know about your canister system of removing phosphates, my phosphates are at 2.0 which is considered high but not as high as my nitrates which are 160. I only have a few SPS corals and probably can't keep delicate ones because of this.
I like LPS and soft corals better anyway so it works for me.