How small is too small?

[treesprite]

It made no sense to have quiet tank plumbing if there was noise from under the stand, so when I set up this system I ended up using a little 100gph fountain pump as the return from my second sump (skimmer/fuge) back to the primary sump (tank drains/main return) - everything bigger created water noise. I didn't think it would have any negative effect, it would just allow more time for the skimmer to process stuff, but I figured since I'm bored, that I should go ahead and make a post to ask what people think about using such a small pump. I don't want any water noise.

 

[ReefdUp]

Rather than worry about what is too small, why not just address the problem another way? Our stand and pipes have sound-deadening material. 

 

 

[Jon Lazar]

It's neat to see an innovative approach, but I'd be worried that a fountain pump isn't robust enough to serve as a reliable return pump over the long haul.

 

It's possible to achieve a silent system with a larger pump.  Silence was an important design requirement for our build, so I used modern, quiet pumps to deliver significant flow with no water sounds.  Two Vectra L1 closed loop pumps provide lots of flow but are completely silent.  I have to look to tell whether the pumps are on.  And I haven't enclosed the stand yet so the pumps are exposed.

[treesprite]

I'm talking about water noise, not pump noise. It is the simple standpipe plumbing from the first sump into the second sump, and the water/air coming out of it, that cause the noise; it would probably be better with smaller pipe, but the bulkhead is 1" and the 1" standpipe is glued together, I can't take it apart to reduce it, only put a reducer at the output, which I did down to 3/4". Insulating the stand might make a difference if I have to use a bigger pump.

 

These are the kind of pumps sold with or for pico setups, but are look like the ones sold as little fountain pumps so I just called it a fountain pump - I didn't actually take it out of a fountain (the only time I ever got a fountain was to use for the cat's drinking water).  I have been using this one for several years off and on in QTs and small, temporary tanks. It has the same size nozzle as a Maxijet 1200, and has a flow adjuster valve on it. I used it in the 12g Aquapod at times when the Maxijet was too strong for what I was doing. I was just guessing that the max flow setting is 100gph because of its relative size (since I can't remember the specs or brand) - it may be closer to 200. I tried using a Maxijet for the return, but got the water/plumbing noise, and this was the next option for what I already had in the tank junk collection.

 

Based on what I have read various places, the majority of people have the opinion that flow for a skimmer section should be low, that lower flow means less water simply getting returned before it has a chance to be skimmed. I haven't seen anything about being really low, basically people recommend between 200 and 300 gph. 

 

 

[treesprite]

Ok well, I took the pump out to look at it. It has a label on it which I couldn't see without taking it out. It is a Via Aqua pump, rated about 118.8 gph. 

[treesprite]

One of the things I read today/yesterday said something about how the flow in the skimmer section should match the amount of water the skimmer can process. Is the amount it processes the same as the amount of water the skimmer pump sends through it?   I have no idea what flow my pump is set at, because the pump controller buttons don't work (skimmer is working well at whichever setting it is stuck at). It's a Reef Octopus 170 INT skimmer, the pump label says max water intake 1600 lph (about 422 gph).  

 

Just to clarify, the skimmer is in the #2 sump/fuge which is plumbed to return to/be fed by the #1 sump, so there is no direct connection of it to the DT. 

Edited January 4, 2020 by treesprite

[madweazl]

The skimmer's pump should have been engineered to operate the skimmer at full power. My personal opinion is that DC pumps are a complete waste on skimmers (I should probably change that to controllers on skimmer pumps is a complete waste). Dwell time and all that jazz is the least of my concerns and in the end, will have little to no effect on your tanks health.

[treesprite]

9 hours ago, madweazl said:

The skimmer's pump should have been engineered to operate the skimmer at full power. My personal opinion is that DC pumps are a complete waste on skimmers (I should probably change that to controllers on skimmer pumps is a complete waste). Dwell time and all that jazz is the least of my concerns and in the end, will have little to no effect on your tanks health.

 

I kind of agree with you about controllers on skimmer pumps. 

 

It seems to me that the longer the water is in the container, the longer the skimmer has a chance to skim it. Is there anything wrong with flow being so low that the same water gets skimmed several times? It takes longer for the entire system volume to get skimmed, but it seems to me it balances out with the water overall is more likely to end up in the skimmer and not just passing by it. I'm kind of wondering if advancements in rollermat technology will eventually cause more people to do away with skimmers.

[madweazl]

I don't think it will make a difference in the long run unless the skimmer isn't flowing enough water to turn over the entire contents of the tank multiple times per day (no clue what that magic number would be). I don't run socks/mats because I feel all that particulate is feeding something (I have little to no concern with detritus).