Ok Kien pointed out the sound may be from the pellets being forced into the bottom of the reactor plate. Putting my ear up to it this appears to be the case so I'm going to put the bottom red plate back in and get me some of that mesh so they don't contact the bottom.

I realize I'm brainstorming online but hey it might help someone lol!

Alright just me again. I took the same filter floss mesh I use in the back of my tank to filter my water and sliced it thinner. Trick was finding the right thickness and wrapping it around the bottom plate which i put back in. This keeps it from flipping up and flow favoring one side. Running silently and with a much gentler tumble on my MJ600 still.

After several days of clogging up with mulm, I rinsed off some of the mulm and the rest of these new pellets are tumbling very well in my unmodded Lifeguard Fluidized Sandbed Filter.

Anthony

Pellets arrived on Monday but have not had a chance to get them online until tonight.

The test tank is a 40g semi-cube that houses a pair of clowns, two gigantea carpets, two rose BTA's, a mottled leatherjacket/filefish, a smattering of assorted corals and 3 clams. Due to a bit of neglect on my part (seriously overdue for a waterchange), and a higher than average bioload for this size tank (mysis daily for the fish and 'nems) the parameters have crept up a little and there's a small patch of cyano on the right side glass.

The beads are much smaller than what those who used the first round of pellets available are used to. I called the old ones lentils - these are more like hemp hearts (for you health food fanatics) or maybe slightly larger than sesame seeds. Oh - I know a good comparison - bird seed. This stuff is the same consistency as the seeds I used to feed my budgies I had as a kid.

Anyhow, I added the full 550l to a TLF 150 phosban reactor. The sponges are replaced with quilting mesh pinned to the red plates with zap straps. The feed pump is a MJ12 powerhead.

The MJ12 is too much at full bore (the entire column of pellets slams into the top of the reactor) but seems to be perfect throttled back by valve at around somewhere between 1/2 and 3/4 open.

I can't hear any noise from the pellets that Brett was having so I wonder if it was the configuration after all. The only thing is I have two skimmers in vicinity and a couple loud pumps anyhow so I probably wouldn't really notice anyhow if the tumbling gave a rattling sound.

So day 1 params -
NO3 (Elos) - 1.0ppm
PO4 (D-D) - 0.06 P

Yeah Tony if you scroll up a bit I solved my issue. They're silent now and people don't think I'm crazy anymore (I hope).

Mostly I added my comments only to back up your theory. I wouldn't even have mentioned a noise issue otherwise because they've never been anything but silent for me (minus any rattling from the powerheads anyhow, but that's usually solveable with a new impeller, the powerhead bodies seem to outlive the impellers easily 10 to 1).

A few days ago seemingly out of nowhere these grassy shoots started popping up around my tank. Mostly from the greenest rock in my tank leading me to believe that one is offing phosphates or something. So that sucked.

Now I've been running the pellets one week I guess. Today before lights out I noticed a ton of the green shoots were turning transparent at the tips and many of them appeared to have gotten shorter. I think the algae is getting starved and the dead tips fall off. Could be wrong but I'll post more as I see it.

I also noticed my first bubble algae yesterday so I'll see how that reacts now that these things seem to be doing something.

Pellets are still tumbling PERFECTLY in my TLF with a MJ600. In talking to other users it seems these pellets tumble easier than the previous ones. They are smaller I think and maybe shape has a part?

Day 7 params, a little movement in the numbers.

NO3 (Elos) - between 0.0 and 1.0ppm
NO3 (Pinpoint) - 2.0 ppm (I should have tested with Pinpoint last week for a better basis of comparison but I got lazy - it takes 10-20 minutes of fiddling with the unit to get a steady reading whereas only 3 minutes with a chemical based test kit)..
PO4 (D-D) - 0.03 P

Cyano patch is still there for now. But overall the tank does have a slightly brighter, happier look to it. Hard to describe objectively, but it's stuff like "I swear that coral and that anemone are open bigger than they were a little while ago."

Expensive day for test kits though. Ol' butterfingers dropped the tubes from the D-D test kit shattering one of them into tiny little bits. Which sucks because it's a nonstandard size and it was a, ahem, somewhat more expensive than average test kit at, I think, it was around $80 from J&L. :( I don't see it listed there anymore (nor anywhere else that I checked, except for out of the country vendors) so I'm a little bummed. Gonna post to see if anyone has an old test kit they don't mind scavenging the test tube from so I can continue testing for PO4 as I go along here.

I found that it takes a week or two after adding new pellets for the mulm to stop clumping up the pellets. Added more pellets into the Fluidized bed filter and it wouldn't tumble until Sunday night. The pellets also get stuck in the return at first, but once that is cleared out, the pellets are now tumbling extremely well.