Timed Skimming. Good or bad idea?

[RayD]

I read an article recently (can't remember where) that suggested that using your skimmer less would be beneficial for the reef leaving extra nutirents in the water longer and allowing the animals to absorb these nutirents.

I've been toying with the idea of trying this theory out and add a program to my Aquacontroller telling it to shut the skimmer off during the day and run it at night to remove excess nutirents at that point.

Does anyone have any experience with this theory or does anyone here actually practice this method?

TIA

[nickyblase]

I thought I read recently (I'll see if I can find the thread), that turning the skimmer off all the way will affect the oxygen levels in the tank, and instead to just take the collection cup off, while leaving the skimmer on for gas exchange. Other than that, I can't add a lot.

Lemme see if I can find the thread Ray, and I'll pass it along.

[skyedolphan]

My skimmer has always run on an on/ off schedule.
usually on 3 days off 2 unless I forget somewhere in there then either day gets off/on longer. Mind you I heavy feed and ALWAYS have nitrate around 15-25. My elegance and clams like it and I have not seen anything detrimental to the SPS, LPS, or softies. With the recent electric bills
I am now toying with shutting the reactor down on the same schedule. I have one more week to maintain a 460 Ca level then I will shut it down for 3 days and see what happens.

[Greg Hiller]

I guess it depends what upon what you are trying to achieve. I've always found it a lot easier Adding nutrients to the water than removing them (feed more, add some fish). If you think your skimmer is particularly oversized for your tank, or you think the corals you are keeping do better under high nutrient concentrations, then it makes sense to turn your skimmer off. Keep in mind that for many hard corals, high levels of phosphate will poison the calcium carbonate deposition surface, making it impossible for the coral to put down skeleton.

I'd be very carefully of two things though if you are turning your skimmer off regularly. (1) Make sure you somehow maintain a high oxygen level in your tank, particularly at night when everything is consuming oxygen. If you have an overflow this is less likely to be a problem, particularly if the water travels a long way to your sump and mixes a lot of air into the water in the process. (2) Make sure you are using a pump on your skimmer that is reliable and will restart every time if you are restarting it using a timer, or some type of automation. Some pumps (particularly submersibles, and the Rio's are the worst for this) tend to accumulate calcium deposits in the warm areas of the pump and might not restart. If you were relying on your pump to restart every night at the time the lights went out (due to the low oxygen during the dark phase), and it didn't, you might wake up to some dead or gasping fish.

[capecodder]

I've always believed that the protein skimmer is a double edged sword. I'm not sure if it depends largely upon the type of skimmer. I have a Precision Marine venturi. I think most people today use the Becket type.

Besides removing nutrients, theories abounded that the venturi valve itself was harmful to larvae of copepods, etc. I don't know if the same opinion is held of the Becket type. I've always run mine a few days off and a few days on. After leaving it off, I'd notice lots of things crawling around my live rock. Whether it was due to nutrient buildup, not killing larvae with the venturi valve, some other factor or combination, I don't know. (Incidentally, concerning the Elegance thread, I had one for over a year and thought that my poor upkeep schedule, helped it - esp. when the salinity went off the charts too high and had poor flow)

I wouldn't recommend an auto-timer solution though. The scum will dry to the inside of the skimmer tube and generally needs cleaning prior to rerunning efficiently.