How difficult is it to maintain a saltwater aquarium? Is a larger saltwater aquarium easier to keep?
The simple answer is not difficult at all, with the right advice and right equipment.
The difficulty that most hobbyists experience in any aquarium is due to a lack of good advice and or some help in maintenance services until they become more experienced. What we have seen is that many people start with the Tank and Stand they want, that fits their space and decor, but they exceed their budget when it comes time to buy adequate professional equipment to maintain their fish and corals in a healthy environment. The hobbyist then settles on less expensive equipment. Many hobbyist are told "the bigger the better". Although it is true that the bigger the aquarium the more stable, without the right equipment the big aquarium progressively goes bad and stabilizes bad water conditions, instead of good water conditions, making it even more difficult to correct this problem in the future. The rule to live by is this; consider the fish and corals in your aquarium first and foremost, then the tank and stand and any decor. If the equipment you choose keeps a good healthy environment for your livestock, it will be enjoyable no matter what size the aquarium.
No one ever quits this hobby by saying to others, that "I didn't have the right equipment or advice.", but they will say "It was too difficult to keep, fish kept dying, it was too expensive."
Is a Coral Reef Aquarium more difficult to keep than a Marine Fish Only Aquarium?
Also See FAQ: How difficult is it to maintain a saltwater aquarium? Is a larger saltwater aquarium easier to keep?
The simple answer is; slight more difficult, because it involves more equipment and more decision making.
Coral Reef Aquariums require additional equipment to maintain Corals as well as fish. The two most important pieces of equipment are a good protein skimmer and good lighting. This is where the hobbyist should devote more money, the return is greater than any other pieces of equipment for a reef environment. When it comes to marine fish, stability is essential, but even more so with corals. Do everything you can to promote a clean stable environment. Carefully consider which family of corals you want to keep. Then tweak your equipment towards that coral's environment. Many hobbyist try to mimic 30 meters of reef in 30 inches of water. There are zones that these corals live in within this 100 feet of water depth, that suits them best, pick a zone. Gear your aquarium towards that particular zone. The zone towards the top requires more intense light, cleaner water and furious water movement, where as the lower zones require less, bottom zones may even require more nutrients.
Ask for advice, take your time in deciding which way to take your aquarium. Take it slow.
What is the difference between a landscapers pond and a koi pond?
The simple answer is: Where the emphasis is placed, on the landscaping or on the fish.
Many landscapers make gorgeous ponds in our area, but they are not Koi Ponds. A landscapers pond is more concerned about the water features and landscaping, so less effort and money is devoted to equipment that maintains a good environment for Koi. Although koi are in the carp family as goldfish are, they get to be much larger, reaching 30" over many years. Koi can live 80 or more years. A Koi pond may have all the feature of a Landscaped Pond, the waterfalls, the plants. Koi Ponds however are deeper, have: steep sides, bottom drains, skimmers, pumps, filters and UVs. Basically, Koi ponds are an inground pool for Koi!
A small landscapers pond (6'x9', 18" deep, 500 gallons) maybe as an example $2,000.00, same size Koi pond with good equipment may be as much as $4,000.00! (6'x9', 36" deep, 1,000 gallons) Both ponds may look identical from the surface, but very different when it comes to keeping Koi thriving and healthy.