Not what I hoped for. By Borchers on 11/20/2015
Borchers wouldn't recommend this product to a friend
Like many others have said. My 180i has been a bear to deal with. The tuning took weeks and then some. It's well built but crazy heavy. The pump hums time to time.
Crap pumps By JonnyReefer on 9/10/2015
JonnyReefer wouldn't recommend this product to a friend
The pumps on these things are junk. Mine went out 6 months after buying it. I've been spending the last 2 months dealing with Albert from proline aquatics, who has been nice, but completely incompetent. I sent the pump back and he says it was calcium buildup that caused the problem, which isn't a warranty issue, so he charged me for the shipping AND for a new pump. Within one week BOTH PUMPS WENT OUT. I told him this and he said it must be the placement of my skimmer in the sump, yet my kalk ato goes into the return pump chamber, which is as far as possible from my skimmer, and all my other pumps/powerheads are just fine. Now they won't even return my emails. This company is a joke, this skimmer is a joke, and BRS should be ashamed for recommending them.
Built well, not and ideal skimmer though By Rahul on 8/13/2015
Rahul wouldn't recommend this product to a friend
This skimmer is not a skimmer I would honestly recommend, due to the fact that I've spent 2-3 months of tinkering with this thing to finally get the skimmer to skim properly without overflowing every minute. I cant give this skimmer lower than a 4 star since it does what the product is supposed to do. The only thing I can say is that its very frustrating to get it dialed in.
Would NOT recommend to a friend! By shawngt2 on 8/7/2015
shawngt2 wouldn't recommend this product to a friend
This skimmer is built like a tank (1 star), super powerful (2nd star), but the other 3 stars needed to categorize this skimmer as a "knock out of the park" are missing. So many people are having issues and that includes me. Did not realize the issues until after I purchased it and put it in my tank. Even in an area of my sump that is always level and at 7" this thing overflows, then completely low level and doesn't appear to foam. You can't even adjust it because one minute it works then an hour or so it overflows again. IMHO you need to learn where the overflow level normally is worst case and adjust the height of the skimmer accordingly until you are covered. This however is not easy. The wedge pipe doesn't seem to do anything unless it is 75% closed or more and the outlet T is fixed to the wedge pipe so it is not easy to just rotate the wedge pipe, you need to also hold or fix the outlet T to make an adjustment. Many online are even restricting the airflow to the skimmer with success, so may try that at one point. Going on vacation for a week and put my Hydro Performer 405 back in the sump so I don't go a week with overflows (basically not skimming). When I get back I will try again but if I can't get equal or greater skim within 2 weeks vs my Hydor, this PITA is going for sale!
Awesome By Andrew on 7/13/2015
Andrew wouldn't recommend this product to a friend
After 2 months this thing is skimming better than I thought possible. Installing the Vectra this evening will review that in a month or so.
Very temperamental, but amazing once dialed in By Brady on 6/10/2015
Brady would recommend this product to a friend
This skimmer is build like a tank. Great build quality and very quiet. Only ding against construction is the ozone nipples and tubing. I'm guessing they chose pex tubing to not get degraded by the ozone, but it does make it very stiff and hard to fit and stay on the nipples.That said, this thing is very temperamental when you're getting it dialed in. Make 100% sure the chamber you put this in has a constant water level, remember to adjust the volute on the pump, and if it keeps over flowing, raise it a bit and try again.
Just awesome By Stan on 5/16/2015
Stan would recommend this product to a friend
Love this skimmer. Very quiet. I had no problems tuning it like others have. skims like a beast on a 90g tank. I would highly recommend it.
Long Break in By Andrew on 5/12/2015
Andrew would recommend this product to a friend
I will give a partial review now. I have had this running for over a week and it still is breaking in and overflowing. I understand that good skimmers take a while, but think this is a little excessive. Will provide another review when break in complete
Very finicky skimmer. Dead after 1 year. By ReefMaster on 5/11/2015
ReefMaster wouldn't recommend this product to a friend
This skimmer is very hard to dial in and has a long break in period. It is mostly well built except the ozone nipples commonly break off. After one year the motor stopped spinning when I plugged it in. PVC welding also broke for the part connecting to the motor. This is easily fixed.
Pros: It runs very quiet. And now that it is not working, even more quiet.
I had great hopes with this skimmer, but I could never dial it in. I also have the 150 version for my other tank, which skims great so I am happy with it, but is a little louder and still has similar build issues. They must have just scaled down the other one for the 130 without really thinking about how the dimension changes affect performance.
For the price, I'd recommend going with a different skimmer that will last you, or get something cheaper that will skim better and last just as long.
Vertex Omega 130 is awesome By San Diego Reefer on 4/29/2015
San Diego Reefer would recommend this product to a friend
This skimmer is awesome. It runs better at 6.5 to 7 inches of water. Had a bit of an issue breaking it in but once a I ran it in a 3 to 1 vinegar solution overnight it worked like a champ. Ignore break in instructions and run it in a the vinegar solution to break in faster. Turn the volute on the pump until it seats then back up 1 whole turn and you are there. The only thing that will need to be adjusted after that will be the water level. This skimmer is made of great quality acrylic and pvc. Way better than Reef Octopus well worth the money.
Ditto what Tony said By kirsten on 4/21/2015
kirsten wouldn't recommend this product to a friend
This skimmer is built like a tank. Very high quality. And full disclosure- it didn't fit my sump well. Once I wrangled it into the sump it was very temperamental. I followed the break in instructions to the letter and after a couple of days it was still acting crazy. One minute fine- the next minute bubbling over and spewing spray everywhere. I also found there to be too many moving parts. When you go to adjust the pipe- the whole muffler confraption moves as well. The silicone tube that connects the pump to the skimmer is easy to accidentally disconnect. Maybe I'm just not advanced enough for a skimmer like this. I went back to my old cadlights.
Excellent Product! By Tony on 4/12/2015
Tony would recommend this product to a friend
The Omega 130 is an amazingly built Skimmer, build quality of Vertex is second to none. However, there are a few things that make me knock it down 1 star. The good, Super quiet, Great build quality, looks awesome! The bad, it is SUPER picky about water level, you have to stay on the low end of the "recommended" level, the break in time is crazy long and almost have to keep a constant eye on it, the adjustment are hard to make and get it tuned in.
I have actually sold off my Omega 130 to a buddy that has a sump better set up for it and i will be going with another option.
it is a great product but i would suggest looking on Vertex's website at the instruction before you set up a sump for one, that was a fail on me.
Great Skimmer - Just Get It By japicka on 4/2/2015
japicka would recommend this product to a friend
Ok thanks to the normal way my luck runs, my existing Reef Octopus skimmer died on a Saturday, and after going through 3 of their DC pumps during the warranty period I decided I had enough of their "quality". I spent a ALOT of time pouring over reviews and looking online.
This skimmer is just fantastic, I just got it put together an into my sump, I had to do some re-arranging in the skimmer area of my sump to get everything to fit properly, but it is now on hour 3 of the 24 break in period and it's already settling in, and there are NO bubbles coming out of the output pipe. With it running right now, even during the break in period it is already 10 times quieter than the skimmer it replaced. I mean this thing is basically dead silent. The only noise I hear from this thing is the hum of the motor.
The only places where I deviated from the instructions is that I didn't hook up the ozone tube, moved the little black plug to the volute input to plug it. I will also probably shorten the air intake hose tomorrow as it's a bit long for my set up. I also decided to install the collection cup, but took the plug out of the over flow drain so the entire set up can break in at the same time. I saw a couple of videos online where people did that and it worked well for them.
Again just can't say enough good things about this skimmer, the quality is just there.
broken ceramic rod in flywheel By Edward on 3/25/2015
Edward wouldn't recommend this product to a friend
I'm very disappointed with the reliability of the skimmer. At first it looked well crafted. Then the ceramic rod in the flywheel broke. I had to call Canada for a replacement. Again at first it seemed like no problem they would replace it. It happened 3 times and they didn't want to help anymore, even though it was still under warranty. The motor is very strong, but for whatever reason that ceramic rod just brakes. The motor also easily separates from the bubble chamber which is just annoying. For this money it should really last and be quality. I tried working with them and felt they just gave up. I have a 75gal with 30 gal sump. I had Octopus for a long time and now I'm using a Skimz which I'm enjoying.
great build but By justin on 3/23/2015
justin would recommend this product to a friend
it has great build quality everything is every smooth but I still have yet to find the right hight for it to operate and not just fill with water.
Excellent but touchy By Jbnewb on 3/18/2015
Jbnewb would recommend this product to a friend
First skimmer purchase so nothing to compare it to. Luke is spot on though. Break-in period was four days and producing dark skim. Very easy to adjust, but if you do ANYTHING such as change a sock or add a treatment and the skimmer goes crazy and overflows. Very important to know it is not 11" long. In my 11" sump I found this out the hard way. It is 11&3/8" unless you take the foot mount off and put silicone underneath for support making it just under 11". Very quite.
Very impressed By Mo on 3/18/2015
Mo would recommend this product to a friend
I haven't set this skimmer up. Still waiting for aquarium delivery. Very well packaged and built very well.
Good skimmer By Luke on 3/10/2015
Luke would recommend this product to a friend
Like all skimmers I have owned the Vertex Omega 130 has its pros and cons.
- Excellent build quality (Vertex is the absolute best at this).
- Virtually silent, especially when cleaned simi-regularly.
- Easy to maintain and take apart
- Most importantly, this skimmer outperforms any skimmer I've used when tuned properly.
- Exceptional skimmate production
- Very finicky about water level. Once I raised it to about 7 inches of water depth this was no longer an issue.
- Pump to skimmer connection is very weak. Will disconnect with little disturbances.
- Pipe adjustment is unnecessarily hard to operate. Not as easy as the gate valve on the reef octopus skimmers.
I would definitely buy this skimmer again just because of the good skimmate production but I might consider waiting for the next model of omega's to be released to see if these things are improved first.
Don't buy this skimmer By pmcadams on 3/2/2015
pmcadams wouldn't recommend this product to a friend
My 130 is 5 months old. Breakin time was extremely long and this skimmer is very difficult to tune. The ozone nipple pulled out of the pump housing so I had to seal the hole with silicon to restore operation. The skimmer body, though made out of quality material, is friction fit to the pump via silicon tubing that slips off easily so any movement in the sump will disconnect the pump. The air filter hanger impedes one handed tuning since it hangs on the exhaust stack and easily comes apart if you bump into it while reaching into the sump. Removal for cleaning is cumbersome since everything tends to fall apart. This skimmer is entirely to expensive for the way its is put together. I regret buying it.
Great skimmer By Oregonrain on 1/28/2015
Oregonrain would recommend this product to a friend
I love this skimmer. Just get some bricks for the hardware store to set it on. You can't put it in the sump because it has too much water to work right. I placed it on a couple brings and it is perfect!
Very Quiet, but not perfect By Ed on 1/5/2015
Ed would recommend this product to a friend
Super quiet skimmer; more skimmate than the Coralife 125 it replaced. Got it for a great price on Black Friday. Directions for set up are poor; connector for Ozone broke during setup...
Incredible skimmer (with an asterisk) By Jay B. on 1/4/2015
Jay B. would recommend this product to a friend
I bought this to replace my EuroReef CS5 which had served me well on my 90 gallon mixed reef tank. The 130 is the only Vertex Omega model that would fit height-wise in my stand.
The unit is impressive from a build standpoint. Because the top cup is threaded, it does take a few turns to remove it. Make sure that you measure the height in your stand carefully and then add a bit for maneuvering.
It does take a bit of time to get the skimmer set up perfectly, but follow the instructions in the manual and you shouldn't have a problem. The skimmer IS sensitive to the water level in your sump. I finally broke down and bought a water level controller just to make sure that I didn't have to keep watching the sump level all the time. If the level goes too low, the skimmer stops skimming altogether. This is probably more of a design feature than a flaw, as other skimmers that I have used will tolerate widely fluctuating water levels, but the skimmate quality also becomes erratic.
I highly recommend this skimmer, but it is not for someone who just wants a turn-key out of the box skimmer.
Will it work? By InWyo on 1/3/2015
InWyo would recommend this product to a friend
I give it 3 stars not because of performance but because of broken part. Been waiting to install on response from Bulk Reef.
Opened box and found a very nice looking product. Upon setting up, I found the output tube broken off of the silencer, poor packing of that component. Contacted Bulk Reef by email, no response. Will try to fix myself but don't like to have to fix brand new equipment. The truth in the pudding will be when the pump needs to be replaced. Will they be available?
Excellent protein skimmer. By Iz on 12/15/2014
Iz would recommend this product to a friend
Im gonna use this skimmer on a future project, you can definitely just seen the quality in this product, and i gotta say BRS did a great job shipping it, Thanks BRS
Awesome skimmer, don't be skeptical of the critical reviews By Garry on 12/4/2014
Garry would recommend this product to a friend
After reading and watching a TON of reviews on this skimmer, I determined that the build quality was better than anything else out there, but the skimmer was difficult to dial in. I was skeptical but determined to give it a go.
- packaging is amazing, but who really cares as long as it arrives undamaged, its comparable to Apple products.
- Assembly is a snap, all you need is a flathead screwdriver
- Build quality is as described in everything you read and see, its a beautiful machine. I catch myself staring at this thing in action..really adds to the beauty of my setup. Yes I pride myself on a good looking sump :).
- Don't buy this if you don't have a constant volume sump compartment that this will fit into.
- Don't buy this if you don't have room in your sump compartment to raise the skimmer up to at least 7" of water depth. I started this off in 9.5" of water, overflowed for many many days, I was really skeptical until I raised it up to 7" and WHAM, perfect no overflow and pulling TONS of skimate out almost immediately. Has not overflowed since. I don't have a huge bioload on my tank, and I was nervous after the first few days of constant overflow until I started raising it up in depth, and immediately tuned in and starting pulling dark nasty skimate, my tank is only a few months old and does not have a huge bioload and I was blown away by how much crap this thing was pulling out of the water.
-Follow the directions for break in for the first 24 hrs, then start tweaking the height, don't touch the air adjustment on the pump, start with the wedge pipe fully open, get it to tune at a certain height then adjust wedge pipe to type of skimate preferred.
- I really don't understand what a lot of the other reviews were complaining about, I think if you follow the above you will fall in love with this skimmer, if thats possible. Oh and its dead silent, always a plus.
Sweet deal on a door buster! By Agro on 11/30/2014
Agro would recommend this product to a friend
Wow... I've been looking for a skimmer I can run in my sump with about 8.5-9 inches of water for a while. Either the prices were outrageous or the skimmer was just overkill for my 40b. Although this is overkill on a 40b, it leaves room to grow and worry free care! My old skimmer left a lot to be desired, Just by look and feel I can tell a lot of care went into designing this skimmer!
Still in the break in face, however this is an extremely quiet skimmer for its size!
amazing By Nelson on 11/28/2014
Nelson would recommend this product to a friend
been using this protein skimmer for now 11 months! get it right now on this black friday special!! its worth every penny... quiet great looking and does whats suppose to do skim everything! crystal clear water!
Dissapointed... By Ski on 10/24/2014
Ski wouldn't recommend this product to a friend
This by far is my most hated piece of equipment. I will agree with everyone that it is bulit well and looks great, but I have had this unit for a few months now and it is the most agrivating and tepermental skimmer I have EVER owned...
First off this thing LOVES to overflow, overflow and overflow some more. Think you FINALLY have it dialed in?.. Think again.
I am on my 3rd platform/riser and I have tried it in water levels of 9, 8.5 and 7 inches. Anyhting much less than that it would be too high for the skimmers outlet.
Following comments from previous reviews are 100% spot on!:
" Break in will take a while "
" This thing drove me nuts trying to adjust it. "
" The skimmer is very finicky with regard to the water level in your sump. "
" Many many nights i would wake up to hear a strange tapping noise coming from the stand. It was the lid of the skimmer dancing around as foam and bubbles poured out and back into the sump. "
" If my ATO deposits even one fluid ounce over the line drawn on my sump the skimmer goes ballistic. "
" the build quality is very good with this skimmer and it is stylish. I am just not certain they went for something that would work. Can't say it is worth the headache. "
" I've spent too much time dialing the unit in to return it but in hindsight I definitely should have."
" if you get frustrated easily, buy a different brand of skimmer. "
All in all I am VERY dissapointed and I guess I should have bought another skimmer. lol!.. My cheap, old and small skimmer runs circles around this thing!
Built like a brick house By Paul on 10/22/2014
Paul would recommend this product to a friend
This skimmer has possibly the most amazing build quality I've ever seen for an aquarium product. From the pump to the body to the lid, Vertex does everything perfectly. This is probably my 4th skimmer and it by far is quieter, easier to use, and far better in build quality than any of the previous. Break in will take a while. The manual says to let it run without the top on it for a day. I waited 4 days and still it overflows the cup so I just opened the drain on the cup and am waiting for it to finish breaking in and the foam doesn't overflow the cup. The Sicce pump is dead quiet. I couldn't tell when it was on or off with my cabinet door closed and wow does this thing make a lot of bubbles. Adjustment is super easy and taking the cup off is a simple spin with one hand. I'm very excited about this skimmer and hope to keep it for a long time.
Great product and shipping!! By R22D on 10/20/2014
R22D would recommend this product to a friend
Product package is perfect nicely done to protect the skimmer inside. You don't have to worry about getting your item broken or something. As far of setting up the skimmer, just followed the instructions on the manual. For some people having a problem with the skimmer, try raising it up. At first I have mine sitting @8" of water ended up @6.5" by the third day it start giving me some decent skimmed on the cup. Definitely going to ordered @brs again even I'm @Canada still worth the wait. Thx BRS!!
Not a simple startup By Jay B. on 9/25/2014
Jay B. would recommend this product to a friend
The skimmer is well made and other than a vaguely written manual, it works great ... once you get it dialed in. It is critical to follow the startup procedure exactly, else you might as well not even unbox it.
The skimmer is very finicky with regard to the water level in your sump, but once you find the sweet spot, the skimmer works as good as any skimmer that I've had (this is #5). But if you get frustrated easily, buy a different brand of skimmer.
Great product By Joel on 9/16/2014
Joel would recommend this product to a friend
Works great, mine does best at 7". Actually not hard to dial in at all!! Been running for 4 months tank is 3 yrs old
Terrific Skimmer By Sean on 9/6/2014
Sean would recommend this product to a friend
I have had the Vertex Omega 130 since it came out about a year ago and it is well built and performs well.
The skimmmer builds up a nice dark skimmate with sludge on the cup lid and sides (I carbon dose). I found it works best at 7" depth. I am running the venturi at minimum air intake in a 27g system. Even in my nano system, it can keep a solid head of foam.
It does take a while to quit overflowing and break in though a vinegar bath will greatly reduce the break in period.
High Quality but Very Temperamental By tarheel on 8/8/2014
tarheel wouldn't recommend this product to a friend
This feel this is a very well built with high quality skimmer but personally think that is Very hard to dial in. I have been running mine for 2 months and all i have been able to pull out is light tea collared skimmate do to all the turbulence in the skimmer body.
Agrivating, but skimms like crazy. By David on 7/31/2014
David would recommend this product to a friend
Wow, that's a lot of bubbles. The inside of this thing looks violent with foam. Skimms like crazy, once its dialed in. This thing drove me nuts trying to adjust it. Many many nights i would wake up to hear a strange tapping noise coming from the stand. It was the lid of the skimmer dancing around as foam and bubbles poured out and back into the sump. I would empty it, then adjust it ever so slightly down... days later, no skimmate. One TINY adjustment back up and it would overflow again. Reading other reviews i decided to raise the skimmer 1 inch and try again. After 2-3 more days of mini adjustments i finally got this sucker dialed in. I clean it once a week and its nasty dirty, exactly what we all hope for in a skimmer. I would give it a full 5 star if it wasn't such a pain to dial in.
Very Tempermental By Jason on 7/23/2014
Jason wouldn't recommend this product to a friend
The best way to describe this Protein Skimmer. Be prepared to fight a constant battle with it. If my ATO deposits even one fluid ounce over the line drawn on my sump the skimmer goes ballistic. It is very specific about the water level. This skimmer does not tune well at all, don't even plug it in for two days after you change the water. Past skimmers SWC, Reef Octopus, Bubble Magus, Tunze, the build quality is very good with this skimmer and it is stylish. I am just not certain they went for something that would work. Can't say it is worth the headache.
BEST materials and craftsmanship yet !!! By Mitch on 7/13/2014
Mitch would recommend this product to a friend
Out of the dozen or so protein skimmers I've owned this is the BEST HANDS DOWN !!!
Great skimmer, crap manual/quality control By B roll on 6/22/2014
B roll would recommend this product to a friend
1st the good - a great skimmer, after a 2 day break in and some water level tinkering , followed by 2 days of wet skim; it is not consistently producing a thick dark brown non transparent skimmate. The bad - the manual is crap besides the 3 lines of break in instructions. This skimmer does not work properly at any level above 7.5 inches, and that is a generous statement. If you want fully control it needs to be at 6.5" as everyone else on here states. Why they waste our time saying otherwise is nuts and leaves me to believe that the skimmer was not tested enough under various circumstances during development and pre-market release. 2nd, for a high end company the QC is crap. I don't know if the rubbery white parts were mold-formed or not, but they all have .5" across sections that look all tore up from either sloppy mold process or some sort of melting during the production process. I've spent too much time dialing the unit in to return it but in hindsight I definitely should have. How these sloppy manufactured parts made it to assembly is beyond me. If it weren't for the crap instructions and sloppy manufacturing I would have given this skimmer a 5/5. Functionally it works great if you ignore the instructions and keep it at 6.5-7".
quiet and looks great By troy on 5/17/2014
troy would recommend this product to a friend
this is a very functional and great looking skimmer. its super quiet and very sturdy..
Great skimmer...but you must have patience. By Jimbo662 on 4/17/2014
Jimbo662 would recommend this product to a friend
I'll agree with everything everyone else has said. I set it up based on the instructions. It ran for right at two weeks with a constant overflow. At two weeks I began trying to make small adjustments to get it dialed in. I had it between 7" - 8". I finally saw some reviews where it was set at 6 1/2". I made this change too (water line is about 1/8" above the stand pipe outlet, stand pipe full open and the volute about 3 turns open. And within15 min it began skimming. I've only got my CUC and two small clowns and it's pulling dark tea colored skimmate. Like Joel mentioned it doesn't foam up constantly. After two days the collection cup was about 1/5th full.
Great product By Joel on 3/28/2014
Joel would recommend this product to a friend
I got this skimmer during the Black Friday sale and have had it going now for about 5 months. This skimmer is extremely quiet and very well built. The one thing I would caution is that depending on the bioload of your tank it may be a bit challenging to dial in. I'm currently running a 60g cube with 4 fish. I went with this skimmer as I'm using bio pellets and GFO as my main filtration setup. The skimmer works great but with a low bio load like I have it is a bit challenging to dial in. Right now I have it at 6.5 inches and I get a tea colored skim mate. I usually empty the skimmer cup every other week. I think those that get much thicker and darker skim mate have a higher bio load. As it stands now I have the bubble line below the neck whacks works fine. Due to the bio load it doesn't foam constantly into the collection cup. I like it as it will work well for my next tank upgrade which should be coming in about a year to 18 months. I normally don't write reviews but I felt with this skimmer it was worth the time.
great skimmer By Jason on 3/14/2014
Jason would recommend this product to a friend
Arived in three days. The build is solid as advertised. I had a nice foam. Head in 20 minutes. I set it in 6 inches of water to start and no over flow problems its been running for 4 days now seems to have settled down i raised the water depth to 6 and a half inches so far so good very happy with this skimmer
great product By ryan on 3/2/2014
ryan would recommend this product to a friend
well built and good looking
WELL WORTH THE MONEY! By Ryan on 3/1/2014
Ryan would recommend this product to a friend
I pick this up over the Black Friday sale for a 40 gallon to a well stock 75 gallon upgrade. After following the break-in instructions it's working great. It has no problem handling the bio load of my tank. WHAT A GREAT PRODUCT!!!
Update from 3 star review on the 2nd of Feb 14 By Raymond on 2/23/2014
Raymond would recommend this product to a friend
This skimmer has completely settled down and is pulling black skimmate. Very happy with this skimmer now I guess it just took time to break in on my system.
Well built hard to dial in. By Raymond on 2/2/2014
Raymond wouldn't recommend this product to a friend
I'll start with the good; well built, silent. IMO the not so good; very long break in period even at 7' water height, very hard to dial in. Every time I tried to get the bubble break at the bottom of the skimmer cup it would over flow within a few hours. There is way too much turbulence in the skimmer body. After more than a month it is pulling only tea colored skimmate. I will see if it gets any better over time. I don't think you should have to modify a piece of equipment to get it to work properly. This skimmer is on a 75gal RR tank.
Left Me Satisfied By Preston on 1/6/2014
Preston would recommend this product to a friend
Let's see it says it operates best in water that's at a depth of 7"-9". I had mine at 8.25" for the longest time and it overflowed for a good 6-7 weeks. So finally I got around to making a one inch stand out of acrylic for it and that seemed to be the difference maker.
It's now at a depth of 7.25" and it's skimming like a mad man. It also feels really well built and you can certainly tell it's made out of high quality acrylic. This being the first skimmer I have ever owned, made for a little learning curve as far as knowing what to adjust. The riser tube is the long red tube with a PVC T-pipe attached at the bottom if any first timers don't know what the heck they are referring to in the manual.
The manual that comes with the skimmer isn't very helpful so I pretty much put it together looking at the pictures of a completed unit here on BRS. Box was well packaged. Everything has been working perfectly.
Outstanding By Chris on 12/30/2013
Chris would recommend this product to a friend
great skim mate almost immediately. Found it works best between 6.5 and 7" of water.