And you might be right Tim. That was the suggestion from Ken about cleaning the top layer of my sand bed as well. Well guess what, I can only clean the front and the 2 side of the tank. I can’t get to the back or the center of the tank and I think that where the problem is. And that is why I said that the next time I would elevate my rock and able to access the back to where I can access it easily.
Also, I haven’t add any more sand since this tank have been up. From the book of Bob Goeman. Having plenum over time the aregonite disolve and must be replace. I’m not sure if my sand are being move to the back of the tank cause I can’t see, but I can now see the door screen in some places in the tank. And of course, I don’t know if this also a play in the high NO3. Maybe I should some more sand just to see.
maybe do the part you can get to and leave the back alone? Its worth a try and add some more new sand about .5 to 1" i would think eventually the bed should release it all but may not work again at removing trates until its cleaned. Is it possible to stir the sand in the back by blowing a powerhead at it? without making too much of a mess
well, no one thing works alone in a vacuum. tanks are a constant battle for food between all the bacteria systems. change one variable and it alters the balance. i just learned a little about that. after the picture session ive had a little melt down in the frag tank. it seems when i moved the corals around to do a good glass cleaning, i left a bunch touching each other. they started stinging each other doing damage. about the same time i decided to stop my vinegar dosing in kalwasser. i was dosing a pretty fair amount each day in the kalk to feed a good bacteria culture in the water and sand.
well a few days later i noticed a big increas of bubbles coming out of the plenum sand, and some of the purple dig turning white at the base, or where touching pocillapora, or the sand. and became infected. Im figuring now, the sudden loss of carbon source in the water, vinegar, shifted the load to the sand bed. and it struggled to build up its own bacteria to the needed level. i think it was spitting out some H2S while it was adapting to the sudden new food source, the water bacteria was no longer consuming. got some more brown algea on the glass, and a little red slime on the sand in spots. but seems to be clearing up now .
So perhaps the bio pellets you are using ,reefman, are merely competing with your plenum. balance is everything. but do clean the plenum sand as deep as you can, until it comes clean. that will help. it did in my 12 year old plenum in the 75.
hey ken if you are having a problem with too many corals and them touching each other i could find room in my tank and help you out… thats what friends are for ;D
Have you figured out what you are going to do with the new tank? If not plenum or dsb what way are you thinking? To me plenum and dsb sound the same just think the plenum is stronger? But really both need maintenance. I think they run so well for years and our habits stray to the negative side ex. Over feeding a bit then when the dsp or plenum clog up you get an algae bloom. But maybe after a few years if we clean it in sections and replace half of it it’ll maintain it’s cleaning capacity. I guess it’s impossible to know how long it will last. But when you swipe something across the sand you can see all the brown that gets kicked up. Maybe a certain amount means maint. Needs to be done.
Its not a new tank, its been running for a bit over a year (its a 30g / 20 sump/fuge) Never really did much with it, its ben an unfinished project. Got it running basically, BB, some live rock, a clarkii pair, and a couple mini maxi nems. I never had sps do well in there, but i also never do wc’s and testing, and keep up on it like my big tank.
I’d say it needs a make over, but really it just needs to be finished, and given the proper TLC.
So…I’m gonna do a plenum, I loved kens frag tank, all frags and colonies without much/any rock. And i just can’t argue with results. And it would be cool to have two completely different style systems in my house, just to see what coral does better where (color/growth). and I also plan on dripping kalk in this setup.
…So i have the “sea floor special grade sand” 40 lbs so far. I’d like to go as deep as i can (making the tank shallower) without hurting the performance of the plenum. In my reading from the links it gives guidelines. But Ken, A, any input on an ideal depth of sand? or just go by the garf guidelines?
Garfs plenum calculator says 53 lbs of seafloor sand, and 10 lbs of garf grunge. Is the “grunge” just basically more live sand? i know they state its filled with life, but can i just add 10 lbs more of sand instead? same grain size, or diff? thoughts?
garf Grunge is old decayed matter ,kind of like the fine dust that comes out of a bagless vacuum…some occasional worms,brittle stars broken coral tips etc…
You could just as easily go to Dr macs and get “reef rubble” or ask for all the bits and pieces that come in busted up at the bottom of a new live rock shipment…
that will be sufficient to start the plenum off right…
I was thinking to just add some life/ live sand from my other tank. Garf just listed 10 lbs of it for this setup(seemed like a lot), and i was wondering if it was sand or rubble.
thx for the info
John, I’m not familiar with Garfs plenum calculator, however, from reading Bob’s book. The plenum plate or the space below is at least 2".
Here’s my build on my 120g, 48L X 24W. I use 1" PVC thin walled cut at 20" to give 2" from the glass wall front and back. I cut enough PVC to be able to space them evenly width wide 6-8" apart also with 2" side to side.
Then drill several large hole through the length of those tube so that the water can flow and not get stagnant in the tube, mainly the top side where you will tie the tube to the eggcrate plate. Cut eggcrate to size 2" short of the inside tank dimension. Use plastic wire ties to tie the tube to the eggcrate plate. With this plate it should bring you up to 1 inch and a half.
You then can wrap the plate like a present or just center the plate in the center of the tank then lay 1 sheet screen door material over it, long enough from glass to glass.
Then put bottom substrate composed of one type of coarse gravel only (grains mostly between 2 and 5 mm), not sand, all around the plate and at least 2" on top of the screen/plate. I then put one more set of screen glass to glass on top of that so that the borrowing animals will not be able to dig down to the plate. Then add final 2" of the coarse gravel mix with live sand seafloor to seed the rest of the live sand. So this whole thing will be at least 6" sand bed with the plenum at the bottom.
Like I said before. My mistake was not leaving the surface of the gravel bed uncovered as much as possible to allow unrestricted diffusion of water and oxygen or little vacuuming.
Also, For cleaning the gravel surface, sea cucumbers are particularly effective, as are small Conchs (Strombus spp.), small hermit crabs, and serpent starfish. Small snails of the genus Stomatella they are good herbivores. I also use sand sifters that actively dig deeply, such as various sifting gobies, must a screen installed to prevent them from digging too deeply.
That sounds similar to what i do. Im making John a plenum plate. about the same, eggcrate sized to leave an inch around to the tank walls. and 3/4 or 1 inch pvc lengths tie wrapped to th crate. and then gift wrapped in plastic screen. i like to stich it closed with some braided fish line. I do about 4 inches of the gravel on top. thats it. totally passive once its set up.
When i did the 75 plenum 12 years ago, i bought 5 pounds of GARF Grunge. added it to the brand new plenum and sand, then added some live rock. the grunge was pretty muddy, cloulded up for a few days, and raised the nitrates and phosphates a little. but it was full of life i still have growing. sponges, pods, Chitons coraline. i would get some more when i set up a new bigger display tank. yeah, the one i keep threatening to do the past 3 years. almost there.
John will be fine with some of his live sand to seed. its just a 30 long.
I started using the Jaubert method (plenum) in my tanks right around the same time Bob Goemans did…
He takes the credit for being one of the first in the U.S. to try it , but people like Sprung and Dick Perrin over at tropicorium were already experimenting with it before Bob…That being said -it’s an excellent system…but like its already been mentioned here- keeping it clean & free of detritus is the key…I really think the idea of a remote plenum tank hooked on to the main system works good…Prefilter the water through a pleated cartridge filter and it will last a long time…Even Goemans used a remote plenum in one of his tanks with only a thin layer of live sand in the DT for asthetics…
I used to use 1" pvc pipe placed all around the tank bottom up to about 1/2" away from the front & side glass,& directly against the back…then drilled 3/16" holes all along the inner face of the pvc pipe every 2 inches to prevent dead spots inside the pipes…Cut the eggcrate so it sits right on top of the pipe…on wide & long tanks I would silicone small one and a 1/4 " pieces of 1" pvc pipe to the bottom of the tank staggered so they would prevent the middle of the eggcrate from sagging due to the weight of the sand…
Then I cut fiberglass window screen to fit the bottom of the tank with about 2" extra material all the way around…I would silicone the screen to the back edge of the tank wall to secure it ,then drape it over the front edge of the pvc and put a few heavy objects on the leading edge until the water goes in…
Then added water to cover the screen about one inch and lightly tapped the top of the submerged screen to realease any air trapped under it…
I would then add approx 3" of the florida crushed coral 3-5 mm(geo marine) to the top of the screen…
I washed the crushed coral MANY times before adding it-to remove all the organics & calcium carbonate dust…
next -for a tank that will have fish -I would add another layer of window screen…
I would top off the remaining one inch or so with some heavily washed special grade reef sand 1-2 mm…
a few bits of reef rubble or a tiny piece of old live rock is all thats needed to seed it…
according to Carib-sea: you could use all geo marine 3-5 mm and go with about 5 inches …or all special grade reef sand at about 4"…I prefer the geo marine -especially for a remote plenum…
Many of the tanks I set up over the years with this method worked great…little or no calcium supplements needed and and very low to near zero nitrates…
I would do it in sections, the easiest way I have found to clean my sand is to have a 2" PVC pipe hooked over the edge of my sump going into a filter sock, then use a 3/8 hose with a strainer attached to the end in the tank and the other end goes in the PVC pipe after the syphon starts, then I can clean all I want without draining the tank, just pinch off the hose when the return needs to catch up.
: Thanks tuna!