Oxygenation When Going Skimmerless

[Joeg]

I'm curious how others feel about oxygenation when choosing to go skimmerless. I've recently added a roller mat and am considering swapping my skimmer for a larger refugium. I'm getting good results with the current setup but at times my skimmer overflows with no warning and I'm really not interested in buying a new one or adding a float switch. I'm also interested in the added biodiversity that a refugium could add.

So my question is whether flow through the sump and surface agitation in the tank will provide enough O2 in the water if I remove the skimmer or if I may need to supplement with an airstone.

 

[Deep]

I'm curious how others feel about oxygenation when choosing to go skimmerless. I've recently added a roller mat and am considering swapping my skimmer for a larger refugium. I'm getting good results with the current setup but at times my skimmer overflows with no warning and I'm really not interested in buying a new one or adding a float switch. I'm also interested in the added biodiversity that a refugium could add.

So my question is whether flow through the sump and surface agitation in the tank will provide enough O2 in the water if I remove the skimmer or if I may need to supplement with an airstone.

Switch it off for a few days and measure nutrients to see if you like where they are. Personally I would always run a skimmer for dissolved organics ( which your roller mat will not export). Also without a skimmer you will not be able to carbon dose effectively. Too many downsides.

 

[josephxsxn]

My 40 gal frag had ran without skimmer the last 3+ years, but it does get 50% water changes weekly. Never had any problems keeping corals, fish, or other inverts like RBTA alive in it. The main agitation is the all in one overflow on the back, as water evaporates it kinda waterfalls down before returning.

Maybe put your skimmer on a stand?

 

[LegendaryCG]

An air stone is never a bad thing IMO. However a large refugium also acts as a natural air stone as the plants convert co2 to oxygen. I doubt the exchange outweighs what an airstone provides however.

 

[zalick]

I believe there is some data on this site that shows surface agitation provides significantly more oxygen saturation than a skimmer and the skimmer is somewhat a drop in the bucket there.

The basics were the surface area of the bubbles is far less than the surface area of the surface water.

I did not search the site though.

 

[fryman]

While the widely held theory that skimmers help oxygenate the water seems logical, it's not been tested to my knowledge. Plenty of tanks go without a skimmer and I've never heard of one having oxygenation problems. If you lose power to the powerheads there may be a problem with oxygen depletion but that's true of any tank, skimmer or not.

There are other reasons for using a skimmer, oxygenation imho is not a factor in that decision.

 

[Joeg]

Thanks for the input everyone. I shut the skimmer off a couple of days ago just to see what happens. NO3 has been unchanged and PO4 did increase by .02 but I think that's likely caused by the 1/4 full skimmer cup overflowing back into the sump. I think I'm just going to track things for a while and see if they go sideways.

I'm guessing that I'll be turning it on after a little while but I have to admit that there is part of me that would love to rip the skimmer out. It's a Bubble Magus Curve 7 and can run for weeks without any attention aside from emptying the cup a couple of times but every once in a while it just wildly overflows and I can never pinpoint why. It's just frustrating.

 

[ReefHomieJon]

My skimmer runs without the collection cup, just for oxygenation. I realized a while back that my tanks looks better when it doesn’t run. Maybe because my refugium and coral at this point are uptaking enough nitrate out the water to keep a stable .02. Just a little pink on the salifert.

 

[NanoBoxes]

I ditched the skimmer on my 20g nano and it was fine for a few weeks, then nasty brown fuzzy algae took over the tank fairly quickly which was not an issue prior to skimmer removal. For the past few months I do a 10% water change once a week and tank has never looked better. I'm guessing removing that bucket of water each week is similar or more than what the skimmer removed when it was in play. I do have a filter that dumps water into the surface so I'm sure that adds oxygenation

 

[Harold999]

Personally I would always run a skimmer for dissolved organics ( which your roller mat will not export).

Ideally a roller mat will remove organics before they dissolve.

 

[Deep]

Ideally a roller mat will remove organics before they dissolve.

only maybe some of it - same as a filter sock. Doc in the water from photosynthates etc will need a skimmer.

 

[JCOLE]

If you are concerned of oxygen levels then I would just run the skimmer without the collection cup. Let it overflow back into the water.

 

[beginner_reefer]

How often should I run my skimmer on a new tank? Been going for about 3 weeks now. Have green fuzz starting on the rocks. 2 clowns and 2 shrimp so far. Should have pods and sea lettuce in a few days as well. Just started running the skimmer last night on a timer. Set it to run 1 hour a day 4 times a day for now. Is this enough for it to run or not enough?

 

[zalick]

How often should I run my skimmer on a new tank? Been going for about 3 weeks now. Have green fuzz starting on the rocks. 2 clowns and 2 shrimp so far. Should have pods and sea lettuce in a few days as well. Just started running the skimmer last night on a timer. Set it to run 1 hour a day 4 times a day for now. Is this enough for it to run or not enough?

Not enough. 1hr isn't enough time to build up the foam head. Run it 24/7.

 

[Jacek56]

I'm curious how others feel about oxygenation when choosing to go skimmerless. I've recently added a roller mat and am considering swapping my skimmer for a larger refugium. I'm getting good results with the current setup but at times my skimmer overflows with no warning and I'm really not interested in buying a new one or adding a float switch. I'm also interested in the added biodiversity that a refugium could add.

So my question is whether flow through the sump and surface agitation in the tank will provide enough O2 in the water if I remove the skimmer or if I may need to supplement with an airstone.

Answer for your question is yes. Water turnover through the sump should be 10 x tank volume or better. This rule has been working for me for last 4 years. Adding refugium is good thing in my opinion. Also remember that corals produce O2 during photoperiod, so no worry about level of O2 in the water when you going skimmless

 

[Randy Holmes-Farley]

I believe there is some data on this site that shows surface agitation provides significantly more oxygen saturation than a skimmer and the skimmer is somewhat a drop in the bucket there.

The basics were the surface area of the bubbles is far less than the surface area of the surface water.

I did not search the site though.

I think the evidence of the effect on CO2 from using outside air in a skimmer and CO2 scrubbers on a skimmer show that skimmers are quite important for aeration.

How exactly it compares quantitatively to the tank tap obviously varies and is generally unknown, but to indicate the skimmer is not important is clearly not supported by reefers experiences.

 

[Randy Holmes-Farley]

Answer for your question is yes. Water turnover through the sump should be 10 x tank volume or better. This rule has been working for me for last 4 years. Adding refugium is good thing in my opinion. Also remember that corals produce O2 during photoperiod, so no worry about level of O2 in the water when you going skimmless

The refugium is likely consuming O2 when dark, so if it is not on a reverse light cycle, you may compound a low O2 situation, not help it.

 

[Randy Holmes-Farley]

How often should I run my skimmer on a new tank? Been going for about 3 weeks now. Have green fuzz starting on the rocks. 2 clowns and 2 shrimp so far. Should have pods and sea lettuce in a few days as well. Just started running the skimmer last night on a timer. Set it to run 1 hour a day 4 times a day for now. Is this enough for it to run or not enough?

I would always run a simmer 24/7 for aeration, even if you didn't want to collect skimmate for some reason.

 

[Jacek56]

The refugium is likely consuming O2 when dark, so if it is not on a reverse light cycle, you may compound a low O2 situation, not help it.

I have solution for this. I run my refugium 24/7, no any issues. The goal is O2 production only.

 

[zalick]

I think the evidence of the effect on CO2 from using outside air in a skimmer and CO2 scrubbers on a skimmer show that skimmers are quite important for aeration.

How exactly it compares quantitatively to the tank tap obviously varies and is generally unknown, but to indicate the skimmer is not important is clearly not supported by reefers experiences.

I definitely did not say "not important" .

But I thought there was some data that showed oxygen/aeration added from a skimmer was far less than surface agitation when the surface areas were compared. I even thought it was something you had discussed years ago on RC....but my memory may be incorrect.

However, to the OPs question: there are plenty of people who've run successful tanks without skimmers for decades showing that a skimmer is not a necessary piece of equipment for aeration, but it may be sufficient in the absence of good surface agitation.