Substrate Vacuuming?

[Alaska_Phil]

The 40 gal Long FO tank I'm converting to a reef tank has 3 to 4 inches of crushed coral substrate, with a deactivated undergravel plate underneath.

Should I be vacuuming the substrate when I do water changes?

I've only been taking care of this tank for a month now and the substrate is getting pretty well populated with bristle worms and something that looks like a little 3mm shrimp. So I haven't been vacuuming.

Thanks.
Phil

[Sk8r]

I take it that it is now functioning with live rock as a marine tank. If it were mine---if it were mine and I wanted to raise corals or marine fish, the first question is whether fish were ever medicated in that tank, and whether in particular they were ever medicated with copper. If that's the case, quite honestly, I'd sell that tank to a freshwater person and get one that's never been used. If the answer is no copper and you're sure of that, then I'd strip the tank down to get rid of the substrate and that old filter base, totally. I'd get some big tubs, lift out all the live rock, pump out most of the saltwater onto the rock, and totally remove the substrate, leaving behind any inhabitants that want to stay in the remaining water. Then I'd clean the remaining water with a serious filter (1 micron) until it sparkles, clean the walls, ditto, and replace the sand with aragonite, throwing out that deactivated filter plate, above all else! It's a future chemistry bomb just waiting to go off. If you want to protect your tank bottom from rock impacts, then use eggcrate, which admits sand all the way to the bottom. Then, with a 4 inch base of aragonite sand, I'd put the rock back in, likewise the water, and filter again until it's clear enough to look like drinking water. AFTER THAT, I'd settle back to wait for a mild cycle, and if there are any fish or corals, I'd keep them either in the buckets with bubblers and heaters or at an obliging lfs until the cycle runs its course. And I'd get a skimmer: this tank has been live a long time, and even with all that scrubbing of the water, may be pretty 'hot' biologically speaking: a skimmer will take out anything the scrubbing missed. I know it's a lot of work, and you might get by without doing it, but I fear that crushed coral sand and particularly that old filter down there is going to hand you a nitrate spike sooner or later that will be a total tank wipeout, with all attendant grief and cost. You're at a stage where you can head that off and get the tank off to a 'new' condition, so that you can do just about anything you want with it. I wish I could say go on and ignore that old filter bed, but I have a feeling it is just going to give you the worst kind of problems after the tank has a lot more living in it than it does now.

[TOURKID]

mmmm.. be careful, but itsa a good idea to start early in the game. my tank is almost 5 months old and i sucked the gravel for the first time last week. it spiked my nitrates dangerously high.

I talked to many about it, and the overall opinion was because it sat so long and got so dirt, it was a nitrate issue, but doing it every so often and not letting it get bad, then it shouldent make the water to toxic

now i have a skimmer running and im trying to get my tank back on track. really threw it off

[Alaska_Phil]

Unfortunately this is an office tank, and I don't have a completely free hand for changes. So a total redo isn't an option.

Up untill I took over a month ago, the undergravel was running and the substrate was vacuumed every other week. It's been running as a FO tank for about a year before I took over.

In the past month I've added a skimmer, added PC lighting and just 10 days ago added a little live rock. My Nitrate seems stuck at 20, I know that sounds high, but it was about 100 when I took over the tank. All things considered I'm surprized at the amount of worms and pods I'm seeing.

Phil

[Alaska_Phil]

Here's my previous post detailing the tank and it's inhabitants.

http://reefcentral.com/forums/showth...hreadid=806539

I'm not really trying for a full blown reef, but do want to get some mushrooms, softies and zoo's growing.

Phil

[Sk8r]

If mushrooms and the hardier fish are your aim, the crushed coral substrate should get by: have you got or can you get access to a 1 micron filter? If you rile up the bed while vacuuming, that's the best way I know to head off a spike---just polish the water, and if you get by with that, do it again at your next cleaning. I used to use my old diatom filter on a 100gal piecemeal: I'd pick a spot I knew needed it, vacuum that, then let the bed settle. That way you never get a total overturn: the bed is a biological sandwich that relies on its layers and textures to process things. If you totally overturn it, it will have to re-establish. if you clean a portion at a time, the rest of the bed goes on processing while the disturbed bed settles down again. I'd particularly bear down on those edges and areas where you might be able to suck some of the bad stuff from under that wretched filter. Your microfauna, given good conditions, will outbreed your cleaning, IMHO. Hope that helps.

[Alaska_Phil]

Thanks. That I think I can do. A friend of mine has a HOT Magnum canister I should be able to borrow. I'll do a little of the gravel/coral each time I do a water change.

Phil

[jobiwan]

I don't vaccuum my substrate at all, don't like the idea of screwing up my hypoxic denitrifying bacteria and stirring up all the beneficial fauna, I've got this notion that detritus is nothing but a lot of surface area for bacteria to grow on, it's not like it rots and pollutes the water, after all it's already oxidized as far as it can go. I'll vaccuum it off the surface for esthetics if any piles up, but I don't lose any sleep about it accumulating in my gravel, if detritus really freaks you out a bare bottom tank is the way to go, you can really get anal about getting every little speck out that way those setups can be quite attractive, kinda one of them personal taste issues, one of the coolest things about reefkeeping is that there are many "right" ways to do things, just a matter of figuring out what works for you....

[Alaska_Phil]

I think I'll just vaccuum it like I do my planted fresh water tank. Just very lightly vaccuum the surface of the substrate. That should help prevent too much detrious from building up, without disturbing anything good down deeper.

Sound like a good compromise?

Phil

[sage1970]

I have a 90 fish/reef that has CC in it....

I make sure I have good flow ....this keeps the dirt in the water column where the skimmer can grab it.

I also vacuum my CC when I do water changes. To keep up the "good guys" in the tank I only vacuum around the front edges of my tank...basically where the LR is not at.

This is what has worked for me...and keeps the tank looking nice.

[MarkD40]

I recently removed the riser tubes from the UG filter in my 75g sump after 7 years and deepened the sand bed from 4-6". After many posts to RC on whether I should also removed the UG plates, the majority of the replies recommended leaving the UG plates in the tank vs removing them (which I was prepared to do). The area under the plates would act as a plenum of sorts.

After removing the risers and power heads I was expecting a nitrate spike and tested every day. My nitrates went from 0 all the way up to 2 for a whole week! LOL! They then dropped down to 0 again. That was 1 month ago and everything is still fine. I don't understand why Sk8r feels that leaving the UG plates in the tank sill lead to a "future chemistry bomb", even if a thin layer fo CC is still on top of it.

If there is sufficient sand on top of the CC no further detritis will reach and accumulate in the lower levels. The nitrate that left behind in the lower levels will either diffuse to the surface or be converted to nitrogen gas once the anaerobes kick in. After that there should be no more risk than would be seen with a properly functioning DSB. Perhaps Sk8r can clarify this point.