Water filtration systems in lagoon based vivarium?

[Planaria]

Hi, apologies if this is a FAQ (I did search the forums for issues relating to water filtration, but did not find much that was specific).

We're building a vivarium for red eyed tree frogs. There will be a lagoon portion and I'm wondering what other members have tried with regards to filtration systems. The tank is an Exoterra 18x18x24 and will have about 4-5 inches of water around the "island" that will support the plants, arboreal structures, waterfall, etc.

Any suggestions would be most welcome.

[Mentat]

It depends on water depth, total water volume, bio-load, and amount of water changes you plan to do. Any aquarium internal filter that can work with that depth, should be fine. There are small external canister type filters that you could use too.

IMO (and i'm a beginner with frogs but have kept FW & SW fish for over 48 years), most filters sold for reptile type vivariums have very small media chambers and require you to buy their own designed media; which can cost 10-20 times more than generic. If you are near a Petsmart they are liquidating their Rena XP1's canister filter for less than $30 (around $100 off). Good luck finding one, at those prices most got bought quick, but I got one couple days ago for my future 40 gal. set-up (about twice water volume as yours is planned).