By Bob Goemans
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Bob Goemans corresponds with Rick (Rutherford, NJ)

Rick (Rutherford, NJ) writes...

Hi Bob,

I have a 90-gallon tank setup with live rock, a few fish and a couple of corals (green star polyps and a frog spawn). I'm currently running the tank with an Eheim canister filter and the water looks good, except for the "waste" I can see on the surface. I know I'm going to eventually need a skimmer. My only concern is due to limited space and not having a pre-drilled tank, I don't want to use a sump. I've heard that hang-on back skimmers do not perform as well. I plan to add more corals in the future and don't want to be limited to just a few types. What would be my best and least expensive option? Am I going to have to do away with the canister and get a wet-dry with an in-sump skimmer? I also have a 25-watt UV sterilizer with 5/8" plumbing that I want to include in my final equipment setup.

Many thanks for your help.


Rutherford, NJ

Bob replies...

Hi Rick,

As you may know, scum on the water surface prevents good gas exchange, and often such a condition can lead to dissolved carbon dioxide getting too high in the bulk water. That can lead to an uncontrolled growth of algae, and/or poor health of the animals. But there are excellent hang-on-tank skimmers, such as those from Deltec, Tunze, AquaC, and ESV. Check them out! They are far less expensive than adding a sump and its needed equipment.

As for a trickle filter, its a very useful piece of equipment for the fish-only system, but not recommended for reef systems as it generates copious amounts of nitrate.

Would continue using the canister filter, as they are the perfect filters for chemical filtration, as all water must pass 'through' the media before returning to the aquarium.

And I would consider the UV an insurance policy, something to use if a disease breaks out in the aquarium, not something to use fulltime, as it limits the microorganisms that corals feed upon. I suggest looking into the use of ozone, and dispensing it through a skimmer, a low cost skimmer, not the system's primary unit. If you need more info, let me know.

Hope this helps,



Protein Skimmers

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