Who rates skimmers

[mark]

little dated and yes could be problems but here:

http://www.aquariumcontrollers.com/a...p#skimmerchart

[lastlight]

Best they can do is give you ballpark ideas and then you ask people who have experience with them I think.

[untamed]

I'm recalling that study that recently tried to measure WHAT was being removed by skimmers and how quickly various models removed it.

I believe that their conclusions were that the "larger" skimmer (the one the processed a larger volume of water per hour) removed the measured stuff more quickly, but that all the skimmers tested reduced the measured stuff to about the same level given time.

It struck me that a big difference between the test environment and an actual aquarium is that the aquarium continually generates new waste so a truly undersized skimmer won't ever get the chance to catch up and waste could accumulate.

Yes, I agree...it is more about bioload than actual water volume.

IMHO, size matters. In order to increase the amount of water it can process per hour, the chamber needs to get bigger. Increasing the flow rate with a smaller chamber just reduces the amount of time the water is in contact with the air bubbles (dwell time). In my case, I wanted to get to 1.5x tank volume per hour (600gph) with 2 minute dwell time inside the skimmer. That means that I need to have a 20 gallon chamber....yikes!

After that, I didn't really pay attention to what the skimmer says it is rated for.

[golf nut]

BK will tell you in a heartbeat that you can overdo skimming by buying a unit that is oversize, it simply doesn't work, or should I say doesn't work properly.

I know there is a distinct difference between having the skimmer in the tank with no sump as compared to having a sump with a 10 times turnover, it just isn't the same, the tank install though ugly will work better every time, explaining it is a different matter.

[Palmer]

Originally Posted by Mr OM

BK will tell you in a heartbeat that you can overdo skimming by buying a unit that is oversize, it simply doesn't work, or should I say doesn't work properly.

I know there is a distinct difference between having the skimmer in the tank with no sump as compared to having a sump with a 10 times turnover, it just isn't the same, the tank install though ugly will work better every time, explaining it is a different matter.

If the tank install works better every time then is it reasonable to assume a hang on the back skimmer on the main tank is also better than an in sump set up?

Palmer

[sphelps]

In sump works better because of the overflow effect. The high specific gravity in salt tanks results in proteins/organics rising. the idea of the sump and overflow system is that the overflow constantly sends the top water from the display to the sump.

[steveg]

Hi there, so you are suggesting that the best way to operate a skimmer is to take water directly from the display tank and return it there instead of doing that from the sump?

Originally Posted by Mr OM

BK will tell you in a heartbeat that you can overdo skimming by buying a unit that is oversize, it simply doesn't work, or should I say doesn't work properly.

I know there is a distinct difference between having the skimmer in the tank with no sump as compared to having a sump with a 10 times turnover, it just isn't the same, the tank install though ugly will work better every time, explaining it is a different matter.

[robert]

Brad - I like your theory, it makes sense to me. I have a question though. Which of those 2 parameters is more tweak-able/forgiving - tank volume per hour or dwell time?

For example, I have ASM 5G with about 6gal cylinder capacity. Manufacturer suggested system size for this one is 700gal. Granted, real life users would not put this skimmer on anything bigger than 350-375gal. Now, applying your theory, keeping flow at 1.5x volume of the tank with 2 min. dwell time this skimmer is no good for anything bigger than 120gal. Which parameter would you tweak for bigger system? Volume per hour or dwell time? No, "Get a bigger skimmer" is not applicable answer at this time.

Thanks a lot.

Cheers.

Originally Posted by untamed

I'm recalling that study that recently tried to measure WHAT was being removed by skimmers and how quickly various models removed it.

I believe that their conclusions were that the "larger" skimmer (the one the processed a larger volume of water per hour) removed the measured stuff more quickly, but that all the skimmers tested reduced the measured stuff to about the same level given time.

It struck me that a big difference between the test environment and an actual aquarium is that the aquarium continually generates new waste so a truly undersized skimmer won't ever get the chance to catch up and waste could accumulate.

Yes, I agree...it is more about bioload than actual water volume.

IMHO, size matters. In order to increase the amount of water it can process per hour, the chamber needs to get bigger. Increasing the flow rate with a smaller chamber just reduces the amount of time the water is in contact with the air bubbles (dwell time). In my case, I wanted to get to 1.5x tank volume per hour (600gph) with 2 minute dwell time inside the skimmer. That means that I need to have a 20 gallon chamber....yikes!

After that, I didn't really pay attention to what the skimmer says it is rated for.

[littlesilvermax]

I agree that too big of a skimmer can happen, in real life it rarely happens, unless you are rich (or used to be).

Look at others that have exceptional systems, see what they use and copy them. Don't be afraid to spend a fair chunk of change, it is a very important part of the tank. And, unlike lighting, doesn't keep whacking your wallet with additional costs (cept monthly electricity).

[untamed]

Originally Posted by robert

Brad - I like your theory, it makes sense to me. I have a question though. Which of those 2 parameters is more tweak-able/forgiving - tank volume per hour or dwell time?

For example, I have ASM 5G with about 6gal cylinder capacity. Manufacturer suggested system size for this one is 700gal. Granted, real life users would not put this skimmer on anything bigger than 350-375gal. Now, applying your theory, keeping flow at 1.5x volume of the tank with 2 min. dwell time this skimmer is no good for anything bigger than 120gal. Which parameter would you tweak for bigger system? Volume per hour or dwell time? No, "Get a bigger skimmer" is not applicable answer at this time.

Thanks a lot.

Cheers.

Yup, that is the math...If the chamber size is constant, then increasing flow rate (tank turnover) reduces dwell time and vice-versa. Assuming that you have re-circ'd the G5, then you can control the flow rate. If you haven't re-circ'd, then your flow rate is set by the amount of water drawn in by the NW pumps and you would have no control over it.

Really, controlling flow rate is one of the big reasons why one might choose a recirc skimmer over a non-recirc skimmer.

Given the limitation of the size, I would be inclined to try decreasing flow rate for increased dwell time. Playing with the flow rate a bit is certainly worthy of experimentation for sure.

Plus...if you wanted to increase the chamber size, you can have my old G6 body if you like.