Reduced Flow At Night....?

[sophos9]

I've been reading and some articles I have read suggest greatly reducing the flow rate during the night (approx 6hrs). Now this gets me thinking about the benefits of doing this...

I can see how some of this may be a bit more 'natural' to have times of reduced flow, what I'm thinking is to drop the two main pumps (Seio M's) and just leave the 600lph to keep the tank moving around

Any thoughts or issues that could be created due to this?

 

[SkiFletch]

Great idea, but you have to be careful that you don't go too low and create O2/CO2 imbalances. I'd say just shutoff one seio

 

[sophos9]

Are you relating to too little oxygen, too much CO2? If so then surly the skimmer will keep the water oxygenated enough and the water movement through the skimmer should help drive off CO2?

I have got one pump stronger than the other from day one for things like this...

 

[idlefingers]

I recently treated myself to a tunze 6055 + controller & photo-cell which makes it slow down at night. I have it on pretty much the lowest setting for that and haven't noticed any ill-effects in the tank (and no pH fluctuations).

 

[sophos9]

How did you manage to sneak that in!! Cool things those, is there hardly any flow at night?

 

[Lynden]

I recently treated myself to a tunze 6055 + controller & photo-cell which makes it slow down at night. I have it on pretty much the lowest setting for that and haven't noticed any ill-effects in the tank (and no pH fluctuations).

Nice... that must've set you back a few grand.

 

[sophos9]

Yea I was sitting here thinking "how jealous"...

 

[idlefingers]

I got promoted at work and wanted needed to splurge a bit.

I think the powerhead is brilliant! There's two dials on the controller which you can use to set two different speeds for the powerhead then another which controls how fast it switches between those flowrates, making a pulsing effect in the tank. Then when the photo sensor senses the lights going off, it just switches to the power the second dial is on, so it can be as high or low as you like it. At the mo I still have a koralia in the tank so I have the controller set to make the tunze go to it's lowest setting. When I get a second tunze pump to replace it, I'll probably make it a bit stronger at night..

*edit* a few grand??! it was expensive, but not THAT bad!

 

[sophos9]

coooo000l

 

[andywg]

Once I get my wavebox repaired I shall leave on my three 6045s, but have the wavebox shift off overnight. I do the same with the skimmer, but this is more due to noise than wanting a slower night time.

Does the reef really get calmer at night? I would have thought that the defining factors will be the slacks of any tides.

 

[Musho3210]

if your skimmer is working perfectly, i dont see how it could add much O2 if any at all since its getting coated with organics.

 

[SkiFletch]

Once I get my wavebox repaired I shall leave on my three 6045s, but have the wavebox shift off overnight. I do the same with the skimmer, but this is more due to noise than wanting a slower night time.

Does the reef really get calmer at night? I would have thought that the defining factors will be the slacks of any tides.

More often than not it does Andy... Especially shallower reefs (~20-60'). At night time (barring an approaching storm), wave action on the surface, and often corresponding surge at depth tends to wane. I mean you can't say that every night the reef is calmer than during the day (weather/tides aren't that predictable), but more often than not, it's calmer at night than it is during the day. I haven't been diving at night enough to confirm that myself, but some veteran divers I know claim that to be so.

 

[sophos9]

if your skimmer is working perfectly, i dont see how it could add much O2 if any at all since its getting coated with organics.

the disturbance and infusion of micro-bubbles from the venturi plus the surface disturbance of water coming out of the skimmer is a great way to keep O2 levels up

 

[Musho3210]

well seeing that the bubbles are coated with organics, how are the bubbles dissolving? Surface agiation yes, but i know that my skimmer creates no surface agiation.

 

[SkiFletch]

well seeing that the bubbles are coated with organics, how are the bubbles dissolving? Surface agiation yes, but i know that my skimmer creates no surface agiation.

Agreed, protein skimmers actually do little in the form of gas exchange. They're designed for trapping dissolved organics, not for gas exchange