OASE CrystalSkim 350 Surface Skimmer for Freshwater and Marine Aquariums – Compact Internal Filter for Film Oil and Debris Removal, Quiet, Adjustable Flow, Shrimp-Safe, for Tanks up to 92 Gal / 350 L

Edit- it can suck up the tiniest of shrimplets but have only found one dead one when I opened it to clean out the plant specks. There’s usually a few grazing on the sponge but they are easy to see and I use those handy tweezers that come with it to scoot em off back into the water. Happy with the purchase! (End edit) Built solid, easy to operate and setup. Good quality suction cups and bracket. Very small and compact. Using in a 10gal plantscaped shrimp tank with gravel substrate. Not recommended if you have sand substrates. Excellent with gravels. This is due to the downward water blasting straight down. The intensity of this downwash is based on how + or - you have it set to. My shrimps don’t mind hanging out under it for what it’s worth. I keep it set pretty close to minimum. Silent operation and versatile setup options to best suit your needs. The fine grills seem to be doing a good job keeping my shrimps out but letting the plant specks in (granted it has only been in a day so far but even if they do I’m not worried about em. They’ll be fine till I get to em. Maybe even happy!) I’ll update if anything changes. Note: I did replace the coarse blue sponge it came with for a much finer/denser sponge I cut from an extra foam piece I had from an old filter replacement. I was worried that the insanely difficult to deal with water-meal would be able to go through the sponge holes and go back into the tank. That’s the only mod I did and it’s because I’m using this to fix a problem of water-meal aka pond meal and it’s so much worse than duckweed. Smaller and *far* more prolific. This is making short work of it and for the first time in weeks, I have hope that I can actually beat this “plant” and successfully remove it for good. It’s proven to me to be pretty much the worst. With it taking over a fully stocked, heavily planted shrimp tank, a full breakdown and sterilize was not an option. Manual removal was an proving to be a mammoth exercise in futility. Now that it’s installed, I can’t help but giggle to see the green micro balls of doom get sucked up automatically. I was worried that they would float back up and out and back into the tank when it turns off due to the timer, but it seems the sponge I used traps and hold them perfectly. Rinses off in seconds. I have no qualms with this piece and overall I am super duper happy with this skimmer. It feels quality built and seems like the cost is appropriate. Long story short, This was the answer to a difficult question. “How to remove water-meal in a planted shrimp tank” And boy am I happy I chose this one! I have it on a timer to run for 30 mins every 4 hours. It’s super easy to clean. Just take the top off, use the included tweezers to pull the sponge up and out and rinse off. Easy as pie. No need to turn off, or even remove the unit for this. Great design. It seems like the designer actually knew what they were doing!!! Very rare to see these days. Very refreshing and hope it holds up over time. Super happy to see those micro plants get sucked up. I don’t want to tell you how many hours of my life I wasted with a cup trying to skim these out day after day, clear the surface and the only to find hundreds more the next morning. Literally. This is the way.

Woofers like a charm. Cleaned my surface film in minutes. Takes a second to get it positioned right so the guard is buoyant and the intake low enough for water to flow in at the right rate. Anyone who’s used one of these before shouldn’t have any issue. Quality build good design. Quiet too!

I got the Crystalskim 350 to help with the surface build up I was experiencing in my 75 gal aquarium. As others have stated, it’s not the easiest thing to set up. It is way too powerful. Even on the lowest speed setting and having the filter as far down in the water as it could go, I still was experiencing micro-bubbles. To solve this, I replaced the provided extremely coarse filter pad with a more fine pad that i cut to size. That solved the issue. Although, i expect this is going to lead to more frequent maintenance. My other complaint is the unit i received is grey, not black. Which is unfortunate because my background is black and i was hoping this would blend in. It doesn’t. Construction seems solid, it is quiet, and it made a visible difference in about 30 min. This is my first Oase product, so only time will tell. So far, it does what it’s supposed to. But since i had to modify a $35 surface skimmer, and i received the wrong color, i’m rating the Oase Crystalskim 350…3 stars. *Edit* The micro-bubbles came back. The only solution I can find is lowering the flow rate all the way down. Which reduced the filter’s effectiveness significantly. The filter is not capable of keeping the surface clean on its lowest setting. So its either a semi-clean surface, or microbubbles. I’m knocking this piece of junk down to 1 star. This is what i get for not getting a Fluval. If the Fluval sk400 was easier to find in America, I would have never went with this hunk of crap in the first place. Avoid this purchase.

Great skimmer. Perfect size for 20 gallon high but needs to be at lowest power if you also have a wake maker. The little thing can create a CRAP ton of micro bubbles at full power. The only complaint I have is that the sponge filter has too large of pores for my needs of filtering out silt. While it still filtered out some silt, I have purchased a sheet of aquarium sponge to custom cut to the size. Honestly, if you spend a couple bucks on a better quality sponge, this skimmer is worth the price! It is very small but powerful and doesn't any noise if installed correctly. The skimmer is the only filtration I have in my tank and it is working great!

One morning I noticed that thin oily film forming on the surface of my tank — the kind that makes even crystal-clear water look dull under light. It bothered me more than it should have. I added the OASE CrystalSkim 350 Surface Skimmer, and within a short time the surface looked noticeably cleaner and more reflective. 🌊 Surface Film & Debris Removal This is where the CrystalSkim really shines. It pulls in surface film efficiently without creating a whirlpool effect. Within the first hour, that hazy layer was mostly gone. Over a few days, the water surface consistently stayed clearer, which improved overall light penetration and shimmer. 🔇 Quiet Operation For something constantly running at the surface, it’s surprisingly quiet. There’s a soft hum if you’re standing right next to the tank, but it blends into normal aquarium background noise. No rattling or harsh suction sounds. 🔄 Adjustable Flow The adjustable intake is useful. You can dial it down if you have a smaller tank or sensitive livestock, or increase it for heavier biofilm situations. I appreciated being able to fine-tune it instead of dealing with fixed, aggressive suction. 🦐 Shrimp-Safe Design This was important to me. The intake design prevents shrimp or small fish from getting pulled in, and I’ve seen no issues with curious invertebrates exploring near it. That peace of mind matters in planted or shrimp-focused setups. 📏 Size & Fit It’s compact and doesn’t take over the tank visually. Compared to some bulky surface skimmers, this one blends in fairly well. It works for tanks up to 92 gallons, but it doesn’t feel oversized in mid-sized aquariums either. 💰 Value for Money OASE equipment tends to sit in the premium tier, and this follows that pattern. It’s not the cheapest surface skimmer available, but the build quality, quiet performance, and consistent film removal justify the investment if surface clarity matters to you.

I have multiple tanks and all but one will grow a layer of biofilm (the oily film) on the surface. I have tried two other skimmers and this one is by far the best. It does a great job at removing the film and is easy to clean. The main selling point for me is the outflow points downward instead of off the side. What I found with other skimmers is I had to turn up the flow rate quite a bit to get a good downward suction to remove the film, but this created wayyy to much outflow in the tank. This one does the job on the lowest sitting and since the flow points down, there's not much disruption in the tank. It's the most expensive skimmer but also the highest quality, you get what you pay for. It's the only skimmer on Amazon that has a downward flow so it may fit your tank's need better. This is the one if you want a skimmer that doesn't generate too much outflow.

This is exactly what I wanted (size, function, appearance). The flow rate has good amount of controllability and the pump is super quiet. It took me about 10 seconds to get the flow and height set appropriately to skim the surface of my tank. To the users experiencing bubbles or extreme flow, it is a user error, not an error of the device. Also if the flow is set too low, it will still pump but not actually skim. I could not be happier with this device.

This does what it's supposed to do - it eliminates surface scum in my 75 gallon freshwater tank in a hurry. It is pretty small in the tank and not too visible. Mine arrived and is definitely more gray versus the black that is shown on the product page on Amazon. The negatives - OH MY GOD THE BUBBLES! After significant trial and error I've finally got mine positioned where it doesn't throw out many bubbles at all but it took A LOT of small adjustments. And in the end I can't even use the secondary strainer part which was also a big factor in why I chose this one over the Eheim. With using just the outside clear skimmer attachment mine is working well without bubbles. But I have been unable to find any setting where I can use that other part that it doesn't immediately flood my tank with bubbles. Disappointing for sure. But function and luckily I don't have many small fish or shrimp, so hopefully nothing will die because of it. I keep mine set on the lowest setting and it works great in my 75g. If I turn it full blast...yep you guessed it...once again more bubbles.

Amazing product, however this listing is for the US version, which is 110V and UAE has 220V so this device will just overload and get damaged mine worked for 3 days before giving up, I did not notice the voltage rating sadly, Amazon was nice enough to refund me. Look for the UAE version or a 220V version of the same skimmer, it was amazing when it worked.

Great piece of kit and cleared the surface up in just minutes as I had seen it shown on YouTube.

der Skimmer funktioniert in der kleinsten Einstellung bei meinem 450 ltr. Aqaurim ruhig und leise....das eingesaugte Oberflächen-Wasser strömt nach unten ins Becken.......bisher noch keine jungen Guppys bzw. Garnelen eingesaugt. Hat ja auch einen äußeren durchsichtigen Schutzring und nochmal ein Einsauggitter...die Silikonhalterung ist auch 1 A !

worked less than a month.. :( it's expensive

se ve bueno, solo que las instrucciones no son muy buenas, algo complicado de entender, al principio, salieron muchas burbujas y estresaron a mis peces y corales, pero despues de unos minutos se arreglo solo, la capa aceitosa que se formava hasta arriba desaparecio en 5 min! funciona perfecto para mi nano reef! solo estaria bien que mejoremn sus instrucciones.