Turning Off Filtration @ Night OK?

[margi800]

During a visit to the Monterey Bay Aquarium recently, I learned that they turn off their filtration systems @ night and allow the natural sea water from the bay to enter their main tanks.

I decided that might be an interesting thing to try in my closed system, i.e., allow the refugium water to freely interchance with the main display without filtration. Mostly, I'm concerned with my filter feeder population which is slowly growing (LFS guy loves me) and I've also recently added a green mandarin. I had been concerned and wanted to make sure the pods in the refugium had a chance to replenish the main display.

So here's what I've done about every 3rd night for 10 days -->
* Turned off protein skimmer from ~ 10pm to ~ 6am
* Removed bubble socks from around the sump overflow/intake
* Set aside filter pad
* Changed lighting in refugium to reverse daylight to encourage
the little buggers to be active during this timeframe

So far, every morning after doing this, my fish seem more colorful, the soft coral polyps extend nicely, and the red scallop and feather dusters seem to be more open.

Question: Has anyone else tried this?
Question: If yes, what were your results?
Question: Am I imagining good results because it's added an
extra step to the bedtime routine around here?
Question: Are there any long term consequences to doing this?

Thanks in advance for any postings - I read a lot on this website but didn't find anything recently on a topic like this......if there's
another thread like this, please point me in that direction!

 

[psyco_guy_abd]

The only concern I see is that your oxygen levels (which already drop at night) might get very low because your also turning off your skimmer. May not be an issue depending on how the rest of your tank is set up, if it is a problem you could add an airstone and air pump on the circuit with the fuge lights so they both come on at night.

 

[margi800]

Thanks for the post. Actually, lower oxygen levels at night was one of the reasons I went to the reverse daylight on my refugium. Currently, one of the overflows goes into the refug. and creates a nice bubble flow in there. I need to keep this in mind.
BTW - what's the best method for testing oxygen levels? It's
something I haven't added to my reg testing routine yet.
(reef is 8 months old). Do I need to wake up @ 3am to test
when it would likely be lowest? Or hourly and for how long?
Does anyone get any sleep when they start a new tank?!
M-

 

[triggerfish1976]

How big is the refugium and do you run a reverse light cycle on your refugium?
Keep in mind that the Monterey aquarium is basically flushing their system and bringing in new fresh water (think of it as a big water change). If your refugium is 300g like your main display then there may be some benefit filtration wise to doing this but as far as planktonic food for your corals go, it is not making a difference either way IMOP since fuges just do not produce most of the planktonic foods that our corals consume in sufficient quantities.
Have you tested the water to see if the nutrient load has diminished over the 10 day period?

 

[margi800]

The refugium is about 70g, on reverse light cycle.
I mostly started to do it to allow the pods to have better
access to the main display, but found that the corals seemed
to look better. Mainly, I removed the bubble socks to allow
the pods better access, and turned off the protein skimmer
so I could feed the corals at night without the skimmer removing
the liquid food I had put in. I probably should've controlled the
experiment better, and will isolate in future tests.
BTW - I don't test for nutrient levels - what's the best way?

 

[Icefire]

They do it because they do a water change with NSW.

Shutting down filtration isn't really good, higher dissolved organic = nitrate can form, low oxygen, low ph, high co2.

Do you really find many pods in you skimmate?

Shutting the skimmer for 1-2h for feeding is fine imo.

 

[bureau13]

I wouldn't expect the skimmer to skim out pods...filter socks/pads may be a different story, depending on how porous they are and which kind of "pod" we're taking about. However, the OP did mention some sort of liquid food, this might get skimmed out. I know the pappone folks like to remove the skimmer cup on the night of feeding, but leave it running for the aforementioned O2 level reasons.

jds

 

[margi800]

Yes - you got it.
Filter socks filter the pods. (I try to capture those that survive
and put them in the main display tank.)
Skimmer removes the liquid food I add for filter feeders.
Regarding O2 levels at night, this is why I went to reverse
daylight on the refugium, I'd read that the natural processes
in the ref. produce 02, and good to do that at night when the
levels tend to fall.
Leaves me wondering if the daytime O2 levels are adequate now?
What's the best way to test for saturated O2?

 

[ntrlfive]

i turn off my skimmer at night, but only because my tank is in my bedroom and its loud, but i also hear its good to turn it off not to over skim

 

[stevedola]

overskim? i thought there was no such thing.