I've had my CSS 125 running on my 75gal tank for 5 months now. Here are my thoughts, observations, suggestions.....
It is a great product for the money, but takes PATIENCE to get it dialed in.
The adjustment knob isn't "sensitive". It is insanely neurotic! The dial rotates a full 180 degrees, but finding the "sweet spot" can take hours of just barely touching the dial- depending on how twitchy your fingers are.
Once you find the right spot, it works flawlessly. It will pull out some of the nastiest gunk you have ever seen. It is not uncommon for the waste in the collection cup to be just as dark as coffee.
To find the right dial setting- open the dial until it starts to wet skim and then shut the dial down as slightly as possible. KEEP AN EYE ON IT! More likely than not, it will start to wet skim again and you'll need to shut the dial down a bit more. Keep dialing it slightly down any time it begins to wet skim.
The biggest mistake you can make with this unit is getting impatient for it to start collecting and opening the dial too far. Trust me- if you follow that last step, it will pull out gunk very well. Give it at least 4 days before you tweak the dial open a bit more if you have nothing in your collection cup.
Microbubbles in tank- I'll just repeat what dozens of others have said on this topic. Expect them in the beginning, but they will disappear after a few days. If they last for more than a few days, you may have a problem elsewhere. I had a MAJOR problem with microbubbles when I first installed my unit. After taking a closer look, I saw that they were coming from between the needle-wheel pump intake cover and the pump. Apparently I didn't get a good seat between the cover and pump when I put it together. That was easy enough to fix just by repositioning the intake cover.
Overflow- will it or won't it? Under "normal" operating conditions (dial set within parameters) it is impossible for it to overflow. There just isn't enough pressure to allow the water to escape once the collection cup fills- other than back into the main chamber. On the other hand, if you have your dial set significantly too high, YES, it will overflow. As matter of fact, (and I don't suggest you try it unless you are VERY curious) opening the dial all the way will force enough water to spray out of the collection cup breather to make Old Faithful jealous.
Maintenance- Following the manual is always your best bet. But I never do, and here is what I know- Anyone that has used a venturi knows that salt will build up and block the air intake. Just let the venturi air inlet suck down some warm fresh water and it will most likely remove the salt blockage. Last week I noticed a MAJOR decrease in bubble production that was helped by warm water, but nowhere near sufficient. I planned then on doing a major cleaning on my skimmer when I did my scheduled water change today. I guess it was a good premonition because when I got home from work this morning there were absolutely NO bubbles in my chamber. I removed the entire unit from my tank. I took the pump apart and cleaned it thoroughly with fresh water. I also cycled warm fresh water through the air-inlet silencer several times (yes, it definitely had salt build up in it). After getting it put back together and reinstalled, it is JUST like new. I mean EXACTLY like new. Microbubbles leaking out of the diffuser box and all.
Modifications- I have already posted about how and why I placed a shield over the diffuser box. In a nutshell, the box sprays and my lighting canopy sits directly on my tank.
The bottom line- It is a great product. Once you have a setting on the dial that works, don't fiddle with it!! If it isn't puking huge amounts of gunk, then you can rest assured that there isn't a ton of gunk in your tank that needs to be removed.
The main drawback of the CSS is the sensitivity of the water level adjustment dial. If Coralife would simply gear the dial down by 50%, it would be perfect. I would have already suggested it on ESU's message board, but the moderator has been MIA for over a month.
