Skimmer?

[Flumpus]

Something in another thread made me think of this, and I have a question. At what salinity does a protein skimmer start to become effective? I know the pinned topic says 1.006, but is it of any great benefit at that salinity? Will it just become more useful as I raise my salinity? Any comments based on personal experience are much appreciated.

 

[nmonks]

Personal experience is that at 1.010 it collects quite a bit of waste, certainly enough to be worth using if you have one lying around. Especially if you have something nitrate sensitive, like a puffer. This was back when protein skimmers were big tall things with air pumps running them, so the modern ones might be worse or better. Can't comment.

Cheers,

Neale

 

[Flumpus]

I have no experience with skimmers at all, but my LFS always has very large skimmers in the used section for pretty cheap (at least it seems that way). My 75g is at 1.007 now, so I expect I'll be over 1.010 in a month and a half or so... I'd definitely like to add one, so is there anything I should look for when I'm looking at these used ones, assuming they have all the parts and are functional?

 

[CFC]

I have used skimmers on my brackish tanks and they definately remove something from the water so are worth using, as nmonks said they work best at 1.010 or above but will continue to function down to 1.006, lower than this the foam doesnt develop enough to be of any use.

 

[andywg]

I would recommend a tall air stone driven skimmer if you are going to use it at a lower salinity. I read a great piece on the science about the optimal skimming formula and it found that most skimmers are not tall enough and do not have enough air pumped in for the flow going through. A venturi can only get more air by pumping in more water, whereas an air stone driven skimmer can just have a bigger air pump and more stones put in.

If you check the internet there are some pretty good and easy to follow DIY plans around.

 

[Gelfling]

I've been looking at skimmers recently as well. From what I've read so far they look like a great thing to have in 240+L with 1.005+SG tanks so I want one. However, I can't seem to find out what pump I need and how powerful said pump needs to be in a 246L tank. Can anyone help?

Cheers,
Stuart.

 

[andywg]

I've been looking at skimmers recently as well. From what I've read so far they look like a great thing to have in 240+L with 1.005+SG tanks so I want one. However, I can't seem to find out what pump I need and how powerful said pump needs to be in a 246L tank. Can anyone help?

Cheers,
Stuart.

That will all depend on the size and type of skimmer. If you have an air stone powered one (with an air pump as well) then you don't want a huge flow-rate as the longer contact time with bubbles will aid in the skimming. Some hydrophilic compounds require 2 minutes of contact time with a bubble to leave the water column.

However, if you run a venturi driven skimmer where the pumping of water into the reaction chamber pulls in the air then you may need a higher air flow.

There is an equation that gives the optimal skimming conditions (flow rate vs contact time vs air flow etc) which I will try and find later. It essentially shows that the ideal skimmer will be about 6 feet tall and have seperate air injection from the water flowrate.

 

[Gelfling]

andywg,

The skimmer I'm looking at is an air stone skimmer, i.e. this one:

Protein Skimmer

Thanks for your help,
Stuart.

 

[andywg]

I think you would be optimistic expecting one quite like that to effectively skim 250l, though it certainly wouldn't hurt to put it on.

I would recommend getting a fairly large air pump (it doesn't look like it really needs a powerhead or water pump) and then just having the flow adjusted down to a necessary amount. I would even consider having a pond-style air pump to ensure you get enough air in. If you find it works ok and you have a large enough air pump you can always put another one on, or design a slightly better one and make it yourself.

I would possibly consider having the skimmer near a filter outlet to ensure it is always taking up newer water.

 

[Lyle]

I recenty bought a protien skimmer for my 55 gallon. my SG is about 1.008-1.009 and i can really tell a difference. i would not suggest getting one powered by airstones, i've heard they're just not that powerfull though i have no experience with em. mine was $100 and its good up to a 100 gallon tank (even though mines only 55, its always good to go up) and has a powerhead. i would definitly suggest getting one!

i got mine from petsmart, but here is a picture with a quick description of the model i have (Seaclone 100)
http/www.aquariumsystems.com/skimmers.htm

 

[andywg]

I recenty bought a protien skimmer for my 55 gallon. my SG is about 1.008-1.009 and i can really tell a difference. i would not suggest getting one powered by airstones, i've heard they're just not that powerfull though i have no experience with em.

They will be as powerful as the air pump powering them. As mentioned above, the way to make most skimmers more effective is to put a higher volume of air into the reaction chamber per unit of water passing through. If the air is drawn in by the pump you have to pump more water to get the air and as such there will be not be more air per amount of water passing through the reactor.

Recirculatory systems overcome much of this (those such as the larger deltec skimmers with aquabee or eheim pumps mounted on the side) but they will not be as effective and tend to cost a lot more than a very tall air stone driven skimmer. The problem there is having the space for a 6 foot tall skimmer. and ensuring that despite the slow flow throught the skimmer (experiments suggest the bubble can continue to remove DOCs for 12 minutes) manages to cycle all of the system's water through the skimmer often enough.

 

[Gelfling]

What model powerhead did you get? From what your saying the air stone method is out and powerheads are the way forward.

 

[Lyle]

my powerhead came with the skimmer. i know 100 bucks is pricey but its comes with everything you need. i'm not very experienced with protien skimmers because i'm new to the whole brackish thing. i've only heard other people suggest a powerhead rather than an airstone, but what andywq said does make alot of sense. the seaclone 100 is the only protien skimmer i have personal experience with but i really can tell a difference. it made an impact on my tank almost immediatly, my water is alot more clear and my nitrite, nitrate and ammonia levels are very much under control. good luck!

 

[Flumpus]

Anyone have any opinions on the Tunze DOC skimmers?

 

[andywg]

Anyone have any opinions on the Tunze DOC skimmers?

I know a lfs employee with one and says it knocks spots off of Deltec skimmers. Most people rate Deltec as the best skimmer so that says something.

At the end of the day, if it is made by Tunze it is going to be good. they were the first company to implement venturi style skimmers and if there is one company that does its research into making a product great it is Tunze. However, this comes at a price. Tunze goods are higher priced (as most are hand made) and are far from easily available.

If you can pick Tunze stuff up cheap second hand you are laughing. I am always on the prowl for any Tunze powerheads or skimmers.

I would recommend the COM-line skimmers as they are a bit easier to have running in tank rather than hanging them on the side of the tank like the older ones.