Is There A Rule Of Thumb, For .......

[Jozlyn]

Is there a rule of thumb, for the litres per hour a protein skimmer should do?

Edit > I actually mean, tank volume per hour. I have my FW tanks turning over 10 times volume per hour.

 

[andywg]

There is a full on equation on the most efficient way to run a protein skimmer comparing height, contact time, through flow rate etc. I can't find it again for the life of me.

The faster the through flow of water the less contact time, but if you get loads of contact time you may not be skimming more than once or twice an hour. anything around 5 times an hour is the usual.

 

[Miss Wiggle]

There is a full on equation on the most efficient way to run a protein skimmer comparing height, contact time, through flow rate etc. I can't find it again for the life of me.

helpful!!

i'd like to see that if anyone can dig it up

 

[Jozlyn]

LOL! thanks guys ...... I think!

"The faster the through flow of water the less contact time, but if you get loads of contact time you may not be skimming more than once or twice an hour. anything around 5 times an hour is the usual."

Have no idea what that means Andy, but thanks anyway!

Ok, what about the, chiller, powerheads etc? Any clues?

 

[andywg]

LOL! thanks guys ...... I think!

"The faster the through flow of water the less contact time, but if you get loads of contact time you may not be skimming more than once or twice an hour. anything around 5 times an hour is the usual."

Have no idea what that means Andy, but thanks anyway!

The process of protein skimming (or foam fractionation) is to remove hydrophobic dissolved organic compounds from the water by utilising the desire of these compounds to "stick" to the outside of bubbles in water.

Different compounds take different amounts of time to leave the water and "stick" to the bubbles. Some need to be in contact with a bubble as long as 2 minutes, others merely seconds.

You essentially come at a copmrimise. The longer each part of water has in contact with the bubbles in the skimmer, the better skimmed it is, but then you have to consider that you might only ever be skimming a very small portion of the tank's water. Alterantively you can have the water flowing through so that all the water is skimmed a number of times per hour, but does not stay in the skimmer long enough for efficient skimming to take place.

The result of the formula is that the best skimmers are air pump powered for the injection as most venturi skimmers do not pull enough air into the skimmer compared to flow rate. To get more air into the skimmer by venturi you increase the rate of water movement in the skimmer and thus do not solve the problem.

Unfortunately, these best skimmers are also in the order of 6 foot tall, so not many people end up using such things...

Essentially, you tend to get what you pay for in skimmers with Deltec or Tunze being the best to buy.

Ok, what about the, chiller, powerheads etc? Any clues?

Chillers are not always needed. Just observe the flowrate stated as necessary for the skimmer you purchase.

Powerheads and general water movement is an interesting one. The old 20x minimum is based on very linear powerheads sending out a very fine jet of water. With the advent of propellor style pwoerheads you probably don't need quite such a high amount as it is a more bulk movement.

'True' wavemakers (that create waves going back and forth across the aquarium) seem to need even less as they work on harmony of waves to create large movement for comparatively little effort. The only Wavemakers like this I am aware of are the Tunze Wavebox and a smaller similar American design which was mentioned a while ago in these forums.

To make matters worse for you, the type of animals you keep dictates the flow rate. Many SW preds prefer a more sedantry 5-10x whereas many people quote 30-40x as a minimum for SPS with 50+x being seen.

helpful!!

i'd like to see that if anyone can dig it up

Then like you shall.

The first post in this Reef Central thread has details of skimming calculations

 

[Miss Wiggle]

helpful!!

i'd like to see that if anyone can dig it up

Then like you shall.

The first post in this Reef Central thread has details of skimming calculations

thanks, i'll probably be bothering you later to explain it to me

 

[Jozlyn]

Thanks Andy, you've been "Tunze" help, LoL, pun' intended!

Have posted a skimmer available in Australia, with a request for feedback, I would appreciate your opinion.

Jeeze but SW is far harder than FW!!!

 

[SkiFletch]

lol, confusing yes, just need to read a lot

A chiller will usually have reccomended flowrate, so match a pump to that flow

As for the tank, some general guidelines:
10x turnover for a softie or fish only
20x turnover for most LPS
30x+ turnover for SPS

In reality you can almoast never have too much flowrate. I've seen people with well over 100x of turnover in their tanks...

 

[Jozlyn]

Damn, I still have no idea what to get!

Given that we're going to have a big tank and use it as a room divider we want to pretty much have as much diversity as possible.

So I guess I should just go for the biggest to ensure that I'm covered for future occupants!

 

[Jozlyn]

Then like you shall.

The first post in this Reef Central thread has details of skimming calculations

You're kidding! I have absolutely less than no idea what the heck the info' on that page is supposed to mean!

 

[sahmof2]

I like using aquaclear power heads. model 402 (now changed to new number model 70) oe smaller. The reason I mention this is that this brand is very reliable both most important is that 402 and smaller models have a variable flow adjustment on them so you can set the flow from the powerhead to get the flow you want in the different levels of the tank.

 

[Miss Wiggle]

Then like you shall.

The first post in this Reef Central thread has details of skimming calculations

You're kidding! I have absolutely less than no idea what the heck the info' on that page is supposed to mean!

me either love

 

[andywg]

lol, confusing yes, just need to read a lot

A chiller will usually have reccomended flowrate, so match a pump to that flow

As for the tank, some general guidelines:
10x turnover for a softie or fish only
20x turnover for most LPS
30x+ turnover for SPS

In reality you can almoast never have too much flowrate. I've seen people with well over 100x of turnover in their tanks...

Having watched the surge of my Tunze Wavebox rip a toadstool in half (such that I have had to place it in the nano tank to try and recover) I would say there most certainly can be too much.

And as has been written before, the type of turnover is at least as important as, if not more than, the numerical turnover rate.

I like using aquaclear power heads. model 402 (now changed to new number model 70) oe smaller. The reason I mention this is that this brand is very reliable both most important is that 402 and smaller models have a variable flow adjustment on them so you can set the flow from the powerhead to get the flow you want in the different levels of the tank.

However, this powerhead has a very linear output, the flow is needlelike and in a narrow stream in front of the output. Far better are propellor powerheads which push a wider stream of water across the tank.