Is it possible to make my freshwater tank into a saltwater tank?

Question

I want to make my freshwater tank into a salt water tank. It is only 20 gallons, but I want to get like clown fish and fish like that. I always take very good care of my tank, and fish. I have some freshwater fish, but I will wait till' they die off. (I know that sounds mean, but they will die eventually) I REALLY want this to happen. Would I need to buy a new tank, and filter? I want to use the one I have now.

Answer 1

It would be possible to convert your tank to saltwater, although a 20 gallon is a little small. You would be able to keep a pair of clownfish if these were ocellaris clowns (the "Nemo" type, as they only get around 2-3 inches), although other species that grow to 5-6 inches would be too large. Generally, the larger you go in saltwater the better, since the fish are less tolerant of changes to their environment, poor water quality, and overcrowding. The fish tend to be more aggressive/territorial, and most grow to a larger size than typical freshwater community fish, so this generally means much lighter stocking rates for saltwater. If your tank is a 20 regular/tall, that would be okay for the clowns. If it's a 20 "long" you might be able to keep another fish as well. I would recommend something very different than a clown for a third fish because their territorial/aggressive nature doesn't allow them to mix with fish with similar colors or body shapes, or members of the same family. This applys to most marine species, so for most groups, this means only one fish per type (tangs, triggers, wrasses, etc.) in the tank. There are a few species that can be kept as mated pairs (clownfish, cardinalfish), and even fewer that can be kept as a school.

If you want to try a third fish, a good place to start your research is with the types of fish you want, and check their compatibility (aggressive vs peaceful), adult sizes, activity levels, minimum tank sizes, and whether or not they would be reef safe, then figure the tank size you'll need to keep them. Then, you can plan the rest of the tank and equipment from there.

There's no reason you can't use the equipment you already have, either - this will save you some of the expense in setting up the tank. For most items, there is no "freshwater or "saltwater" versions. You just want to make sure what you have is appropriate for your tank size.

If you have a stand for the tank, you might need to protect it if it's anything other than solid wood. The particleboard stands won't hold up if they get wet and the glue separates, and the iron/metal stands will corrode if any salt gets on them (or, you could get a metal stand, just use a flannel-backed tablecloth under the tank to protect the stand from splashed water). Saltwater is expensive enough that you don't want the entire system crashing to the floor some night.

Some of the other items you'll need:

FILTER: You want one that's properly sized (filters 5x-10x the tank volume per hour - check the gallons per hour rating). If you want to get a new one or upgrade, there are lots of choices, and what you'll need will really depend on budget, what you're trying to keep, and personal preference. I'd consider the best type to be a refugium or wet/dry trickle filter, but this would be overkill for a 20 gallon tank. Next best would be a canister, followed by a biowheel, then a standard hang-on-tank. Unless you're using a fine sand or oolite substrate, you can also use an undergravel filter to supplement filtration, but I'd suggest powering it with a reversible powerhead to blow the water up through the substrate (prevents stuff from building up under the filter and clogging it).

POWERHEAD(S): To provide more water circulation in hard to get to places. This also helps circulate dissolved oxygen to the bottom of the tank. Having 1-2 depending on their sizes should be enough for your tank.

HEATERS: For a saltwater tank, I'd suggest getting 2 and putting one on each end if you get a tank that's more than 30 gallons. You might even want to do this if what you have is a 20 long. This will provide more even heating, and your tank has a back-up if one heater gives out. Figure the correct size as 5 watts per gallon divided by 2 heaters. If you need to heat the water more than 10 degrees above the room temperature, go one size higher.

LIGHTING: If you never want anything but fish, you can use the standard lighting and hood made for your tank. You might want to upgrade the lamps to a 10,000K tube or a 50/50 actinic. If you're going to try corals, anemones, etc., go with a compact fluorescent, metal halide, or combo system - these will provide more intense light that they'll need for photosynthesis.

SUBSTRATE - you want something made of aragonite to help keep the pH from changing, I like the smaller shell material that Carib-Sea puts out - it doesn't have to be live sand, either. Some folks like crushed coral, but the particle size is bigger than I like, and it tends to have a lot of dust that never rinses completely out. Another very fine grained material is oolitic aragonite (looks like small white balls) and aragonite sand. Here's an idea of the materials available: http://www.caribsea.com/pages/products/dry_aragonite.html While it's possible to keep a marine tank with regular aquarium gravel or no substrate, the aragonite will keep the pH from falling below 7.8 (it should be 8.2-8.4).

SALT MIX: If you're only keeping fish, you can go with one of the less expensive brands of synthetic sea salt. If you get any invertebrates (shrimp, snails, crabs, corals, anemones, etc.), switch to a better quality mix before you add them. These cost a little more, but you won't need to be using additives for the trace elements they need either.

HYDROMETER: This measures the amount of salt that's dissolved inwater. There are two kinds you can get, one made of glass that floats on the surface (more accurate, but easy to break) and a plastic container that has a needle that rises and falls as the amount of salt changes (less accurate, bubbles attaching to the needle gives false readings). For fish only, you want the specific gravity to read 1.020 - 1.026. If you're keeping inverts, you want it to be 1.024 - 1.026.

WATER TESTING KIT: minimum of pH, ammonia, nitrite, nitrate.

CLEANING SUPPLIES: elbow length gloves, gravel vacuum, 5 gallon bucket, large plastic container and powerhead for mixing the salt (to be done well ahead of water changes), algae scraper, razor blades (for coraline algae and diatoms that like to attach to the glass).

WATER CONDITIONER: for removing chlorine or chloramine from your tap water (unless you plan to use a reverse osmosis filter or buy RO water, which is preferred for a reef tank).

The following are optional, but strongly suggested:

PROTEIN SKIMMER: This removes dissloved and small organic materials that would normally contribute to the ammonia, nitrite, and nitrate in your tank. Not 100% necessary for fish-only tanks, but will be handy if you have inverts to keep up good water quality by removing organic materials that become nutrients for algae.

GLASS COVER: This reduces evaporation and keeps the fish inside the tank (some are jumpers), although with a metal halide lighting system, it can overheat your tank.

LIVE ROCK: This give the tank a more natural appearance, provides hiding places for the fish and inverts, and increases the biological filtration. Not to mention, you get all kinds of cool critters that hitchhike into your tank (shrimp, snails, sea urchins, sea cucumbers, sea stars, etc.).

CHILLER: If you use metal halide lighting, or the water temperature regularly gets above 85o (for corals or anemones, fish can take a little more heat), you may need to invest in a chiller to keep the tank cool. The water temperature should run 76-80oF.

There may be additional items that you could need, such as kalkwasser to raise your pH if you can't get it to 8.2, but you won't know these until you get the tank set up and running, and test your water.

Before going out and buying all this, I would suggest some reading to see what you're getting into by keeping saltwater. Since you still have existing fish, this will give you time to to read up on saltwater in smaller doses. I did research for almost 2 years before I set up my first tank, and I had about 20 years of freshwater aquarium experience already. Rushing into a saltwater setup usually doesn't give you good results, and the equipment and fish are a little too expensive to be finding out in a few weeks you got something that's not appropriate for what you want for your tank. I'd also recommend a good reference book for some research. Either of these would be a good one to start with: The New Marine Aquarium by Michael S. Paletta. Microcosm Ltd. ISBN 1-890087-52-1 or The Conscientious Marine Aquarist by Robert M. Fenner. Microcosm Ltd. ISBN 1-890087-02-5

Here are some websites that can also get you started:
http://www.wetwebmedia.com/marsetupez.htm
http://www.peteducation.com/index.cfm?cls=16
http://www.wetwebmedia.com/

Answer 2

You can easily turn your 15 into a nice tank for a pair of clowns, as long as they are juveniles and both added at the same time. If you put two adults together they are likely to be two males and may fight pretty badly. It sounds like you really don't know what you are getting into if you even considered putting a tang into a tank that size. I'm glad you're interested in getting into marine fish. Many people are too indimidated to even give it a try. I would recommend that you get yourself a couple of good marine fishkeeping books. Your First Marine Aquarium, published by Barron's is my personal favorite and is very short and to the point. If you want to do a "fish only" system it would be much cheaper than doing a reef tank. The difference is that the first will take much longer to cycle(build up enough bacteria to support fish) since it is completely devoid of bacteria at the time of set up. The latter is quite expensive before you ever place your first fish into the tank, but it will be more healthy and natural for the fish. For a fish only setup all you need is: 1. A good filter. I'd say for a 15 gal tank get one that filters a 30 gal. 2. Crushed coral. This is a cheap way to cover the bottom of the tank and keep the ph up where it's supposed to be without constant testing and adding. 3. Salt mix. Some people will tell you that Instant Ocean is awful and full of phosphates. This is simply untrue and a way to get you to buy more expensive mixes. I have been using instant ocean for 3 years and my fish haven't complained once. 4. A hardy fish to cycle the tank. Try to find a fish store that will sell you a damsel for you to use about 8 weeks and then will allow you to return it and buy the pair of clowns you want. Don't leave a damsel in the tank. It will be very aggressive as an adult and pick on all your fishies. Please do not set this tank up until you've read up quite a bit more yourself. Don't trust the advice of the pet store employees either. I used to work at one and know that most people who work at pet stores don't know anything about freshwater fish, let alone saltwater, and pull everything they say out of their ***. I hope this helped.:-)

Answer 3

The tank will be find to use but you have to empty it first.

Empty the current water and rinse out the tank with water

Then go to your local fish/pet store and buy some salt, meant for fishtanks and something that is called "prime" Which is in a white bottle with a red label

On the back of the salt bag it should say how much salt to put in for your sized fish tank.

Once you have everything in, wait for the tank to "settle" because it will be very murky at first

Once everything is settled go to a local fish (pet) store and buy a couple of fish that are called Damsels, they are blue colored, and they are just cheap fish that are perfect for starting a fish tank, put those in for a little while, maybe a couple of days, then once everything seems fine, add one fish at a time, don't over-do it

Good luck! I love my 55-gallon tank!!!

Answer 4

Upgrades of equipment may be necessary, but the conversion is easy enough - no need to do much except switch what you want to switch. If you want to have anemones and corals then you will certainly need to invest in a good lighting system. If you plan a fish only tank with fake ornaments, then regular lighting is fine. A protein skimmer is very important - not detrimental, but would certainly make your life a lot easier.

Of course, if you wait for the fish to 'die off' you could be waiting a long time considering how many years a well taken care of fish, even a tiny one, can live. If you wish them gone you'll probably subconsciously kill them, so why not try to find a home for them instead.

Answer 5

Yes, you can do that. Since you have some time, do a lot of research on how to set it up and the equipment you'll need. Usually it's recommended to start out with a larger tank(55 gallons) when doing salt water, especially for beginners. It's just easier to maintain a larger tank. And with a 20 gallon, you'll really limited on the amount of fish you can put in. Salt water fish tend to grow larger, and require more room. I would say you could probably add 2 clown fish, and that's it to that tank. With a larger tank you'd have more options, fish wise.

Answer 6

The tank will be ok to use, but you will need to replace the filter media and gravel. If you plan on going to a reef tank you need to make certain no copper based medications were added to the freshwater tank as this can cause serious problems with invertebrates.

Also, if you go to a reef tank there will be other things you need to buy such as 'live' rock and powerheads for water movement, and a strong lighting system.

But the tank itself and the filter should be ok

Answer 7

You can easily convert a fresh tank to a saltwater one but you first have to get rid of all the fresh water fish and organism that you currently have living in the tank since they won't make it in salt water.

Answer 8

yah it should be fine, just as long as there arent any fish in said tank at the time.

my neighbor has a saltwater fishtank, and she has to routinly go off to the La Jolla docks and have a company fill up her big *** barrels with salt water for her fishtank. i dont know if theres anyway to get around that, but its likely to be more expensive.

either way just be ready to swap out some of the key components and to have to clean it more often than your freshwater.

Answer 9

you can use the same tank, but everything must be cleaned very well. i would recommend getting new gravel/substrate & for sure new filtering.

20 is kind of small for a salt tank in my experience. the chemical levels must be monitored VERY closely to maintain proper balance & fish health!