How to determine if skimmer is sufficient?

[curiousphil]

Hey guys, I've got a question for you all about skimmer selection.

I'm using a Deltec TS-1250 skimmer that I got for free from my gf because it was broken.  As I was just setting up my tank at the time, I thought - perfect!  Something to get me started!  I had been planning to drop about 400 on the Vertex Omega 150.  After fixing it up, it seems to work fine.  But I am concerned that it is insufficient for my tank in the long run, as my phosphates are currently quite high (ranging from 0.5-0.9).  I've been using phosphate sponges to try and reduce this intermediately, and am also installing a GFO/carbon reactor, but these are just bandaid solutions.

As far as I can tell, the best spec to judge a skimmer by is the litres of air/hr.  The TS-1250 is rated for 350 l/hr which seems quite low when I look at others -the Omega 150 for instance is rated at 850 l/hr.  The other thing that seems to come into play is the amount of water you are pushing through the sump.  As I've mentioned in my build thread and also in my sig, I am using a Magdrive 18 for my return pump.  My calculations using 5ft head loss say I should be seeing about 1100-1300 GPH through my sump.

Here is where my question comes in - is there any way to correlate the l of air/hr to sump flowthrough?  If not, how does one go about selecting an appropriate skimmer?

 

[Poseidon]

the gfo is definitly not a band aid solution..
cant believe i ever ran a tank without it...

the deltec skimmer you have,
i run the same one with two pumps on my 150g frag system... pulls out a cup full of thick black goop every week.
5 star skimmer IMO...
i think you'll be just fine.

 

[curiousphil]

Oh, great!  Thanks for the info!  I wasn't able to find many examples of people using these skimmers when searching Google, they don't seem to be incredibly popular.

Someone had mentioned on another site that GFO was not addressing the root cause, which is why I referred to it as a bandaid.

 

[Poseidon]

no its an old skimmer but man it works great...

yea po4 is introduced into your system via foods mainly, it needs an export system and gfo is the easiest way to export it.

 

[AdInfinitum]

If your sump is a place to hold water processing equipment, then flow through rate is relatively unimportant and in virtually all cases unrelated to skimmer performance (+1 to Brandon and GFO...skimmers don't remove phosphates).  If your sump has live rock, DSB or Fuge sections they need way less flow through to facilitate biological processes. 1300gph is the area I am aiming for with my 200gal sump build (goal is more Bio and less Techno) with some areas getting less flow and some more.

 

[spyd]

GFO will certainly help reduce the phosphates in your tank. I suggest replacing it once a month. How many fish do you currently have? Phosphates come from the fish, food and sometimes can even leach out of the rockwork. The last thing you want is major algae issues that will come with higher phosphates. So, reducing the number of feedings, **rinsing any frozen foods**, not over stocking your tank with fish and not sticking your hands in the water all the time will make a big difference in the PO4.

If your skimmer is underrated you will know by excess nitrates in your tank. 350 lph is quite low though. 850 lph for a 90G would be a nice jump without a doubt! My BK skimmer runs at 1500 lph on my 180G with the option to run it at 2500 lph if needed. The lph is definitely something you need to look at when purchasing a skimmer.

 

[Poseidon]

not sticking your hands in the water all the time will make a big difference in the PO4.

i actually heard about this before, and we dont realize how much natural oils we have on our skin and how much this affects water chemistry.... good plus 1, if i ever have to work in my tank i try as much as i can to use my huge pair of tweezers

 

[curiousphil]

GFO will certainly help reduce the phosphates in your tank. I suggest replacing it once a month. How many fish do you currently have? Phosphates come from the fish, food and sometimes can even leach out of the rockwork. The last thing you want is major algae issues that will come with higher phosphates. So, reducing the number of feedings, **rinsing any frozen foods**, not over stocking your tank with fish and not sticking your hands in the water all the time will make a big difference in the PO4.

If your skimmer is underrated you will know by excess nitrates in your tank. 350 lph is quite low though. 850 lph for a 90G would be a nice jump without a doubt! My BK skimmer runs at 1500 lph on my 180G with the option to run it at 2500 lph if needed. The lph is definitely something you need to look at when purchasing a skimmer.

Great advice, thanks!  I've got 8 fish right now., and my nitrates are undetectable, so I guess the skimmer is good enough for now.  Up until recently I had been moving things around a lot, so lots of hand time in the tank.  Now that I'm fully setup I'm dedicating myself to keep the hands out as much as possible.

I've been adding some frozen brine shrimp about once a week, but I'm not really sure how to rinse the stuff.  I keep the bag laying flat in the freezer and then when I serve it I pull the bag out, break a little chunk off, and let it melt/dissolve in the tank water.  I guess I should look at trying to dissolve it in fresh water or something and then straining it...

 

[spyd]

Thawing it in some tank water is fine. Once the shrimp is thawed, then just strain it through a small fish net before feeding it to your tank. That way all the binding phosphates are removed (or drastically reduced).

On a side note, I strongly suggest switching from brine shrimp to mysis shrimp when you can. Brine shrimp has next to no benficial nutrients for your fish, whereas, mysis is considerably more nutrient packed for your fish.