How would you do water changes on a 500g saltwater reeftank?

Question

So they want me to do a 25 percent water change every two weeks, I don't see how this is possible to do in under 5 hours, considering the room the tank is in is really far away from the sink.

Is it really that neccsary to change the water? Isn't their some other way to get the same effect?

Answer 1

Unfortunately, not. The changes aren't only to remove wastes from the tank (although this is important too), but to replenish minerals that the fish and other organisms such as corals, microalgae, and inverts use. You can add supplements to a degree, but this doesn't remove the wastes, and not all supplements will give 100% of the elements needed, or in the correct proportion to what is being used up in the tank.

A python gravel vacuum could be used to siphon water out of the tank and into the sink (these have hoses in lengths to 50 feet, and you can buy longer lengths of hose at any hardware store). I use plastic garbage cans to mix my saltwater (you might need a few of these).

You might also break down the water changes into smaller amounts and do them more often. The amount of water you'll need to change will really depend on the stocking level, filtration, and amount of food given and wastes produced. If you test your water for ammonia, nitrite, and nitrate, you may find that the changes may need to be done more/less frequently or larger/smaller volumes will need to be changed. If you have inverts in the tank, I'd suggest testing for calcium as well.

Answer 2

No, there is no other way. If you leave the same water in there without ever changing it, not only will the water quality degrade, but it will eventually contain such a toxic amount of ammonia that all of your fish will die. Filters do NOT take out ammonia, only water changes can do this. Do some research on how to keep an aquarium going or you will most likely end up with dead fish and never know why. There is a lot more to it than just sticking the fish in water and hoping for the best.

Answer 3

With a tank that large, most people have a dedicated "fish room" where they house things like their refugium, top-off system, controllers, equipment, etc. They usually have a large tank with premixed saltwater, plumbed in, and ready to go for water changes too. How is your tank set up? If you have a large refugium plumbed in, and an adequate skimmer, you can do less water changes, and simply dose the elements that get depleted.

I do about a 10% water change on my 55 gallon once a month, and have had great success (no detectable Nitrates, good coral growth, etc.). I know many people with successful reef tanks who also perform infrequent water changes as well. The primary purpose of water changes in reef tanks are to replenish the trace elements that get used up by your corals. A large refugium, deep sand bed, sufficient live rock, and quality protein skimmer should take care of all your filtration needs. In a tank that large, your parameters should be more stable, and aquarium waste should be more diluted if set up properly.

Since I'm going against the grain here, check out the link below for a good example of a beautiful reef tank that had done only one water change in the past two years! It can be done once you understand your system.

Regards

Answer 4

Yes, fish needs that process because it helps in the nitrogen cycle. If you don't get the water changed by 25%, your ammonia and nitrite levels could increase...

In this case, get a loadful of buckets and get moving. You could use hose but put water conditioners afterwards.

More info of the Nitrogen Cycle:
Some call it the biological cycle, the nitrification process, new tank syndrome or even the start-up cycle. They all are referring to the same cycle - The Nitrogen Cycle. This very important cycle is the establishment of beneficial bacteria in the aquarium and in the filter media that will help in the conversion of ammonia to nitrite and then the conversion of nitrite to nitrates. Check out the aquarium water chemistry page (on the left) for more information on these terms.

This process can take from 2 weeks to 2 months or longer to complete. It is vital for anyone planning on keeping an aquarium with tropical fish to understand this process. Learning about this process will help you to be successful in keeping tropical fish. The best way to monitor the nitrogen cycle is to purchase an aquarium test kit that will test for ammonia, nitrites, nitrates and ph.

Test your aquarium water every other day and write down your readings. You will first see ammonia levels rising. A few weeks or so later you should see the nitrite levels rising and the ammonia levels dropping. Finally, after a few more weeks you should see the nitrate levels rising and the nitrite levels dropping. When you no longer detect ammonia or nitrites but you can detect nitrates you can assume that it is safe to add your tropical fish.



Nitrogen Cycle Stages
Stage 1
Ammonia is introduced into the aquarium via tropical fish waste and uneaten food. The tropical fish waste and excess food will break down into either ionized ammonium (NH4) or un-ionized ammonia (NH3). Ammonium is not harmful to tropical fish but ammonia is. Whether the material turns into ammonium or ammonia depends on the ph level of the water. If the ph is under 7, you will have ammonium. If the ph is 7 or higher you will have ammonia.

Stage 2
Soon, bacteria called nitrosomonas will develop and they will oxidize the ammonia in the tank, essentially eliminating it. The byproduct of ammonia oxidation is Nitrites. So we no longer have ammonia in the tank, but we now have another toxin to deal with - Nitrites. Nitrites are just as toxic to tropical fish as ammonia. If you have a test kit, you should be able to see the nitrite levels rise around the end of the first or second week.

Stage 3
Bacteria called nitrobacter will develop and they will convert the nitrites into nitrates. Nitrates are not as harmful to tropical fish as ammonia or nitrites, but nitrate is still harmful in large amounts. The quickest way to rid your aquarium of nitrates is to perform partial water changes. Once your tank is established you will need to monitor your tank water for high nitrate levels and perform partial water changes as necessary. There are other methods to control nitrates in aquariums besides water changes. For freshwater fish tanks, live aquarium plants will use up some of the nitrates. In saltwater fish tanks, live rock and deep sand beds can have anaerobic areas where denitrifying bacteria can breakdown nitrates into harmless nitrogen gas that escapes through the water surface of the aquarium.

Getting The Nitrogen Cycle Started
There are two ways to get the aquarium cycle started, either with fish or without fish.

Starting The Nitrogen Cycle With Fish
This is not the preferred way to get the nitrogen cycle started because the fish are being exposed to ammonia and nitrites during this process. Many fish can not and will not make it through the cycling process. Often times the fish become stressed and fish disease starts to break out. I wonder what percentage of disease is caused by the cycling of new aquariums?

Certain species are hardier than others and seem to tolerate the start-up cycle better than others. For freshwater tanks, the zebra danio is a very hardy fish that many use to get the nitrogen cycle started. For saltwater tanks, some have reported success using damselfish to get the process started. Again, using fish to cycle is not a good idea and you may be throwing your money (on dead fish) out the window. There is a better way. Read on, young grasshopper.

Starting The Nitrogen Cycle Fishless
There are a few different ways to get this process started. To easily get an ammonia reading from your tank water try the Seachem Ammonia Alert. It sticks inside the tank and has a circle that changes color depending on the ammonia levels in the tank.

Option 1:
Using Fish Food
Drop in a few flakes every 12 hours. As the food decomposes it will release ammonia. You will have to continue to "feed" the tank throughout the process to keep it going.

Option 2:
Use a small piece of raw fish or a raw shrimp
Drop a 2 inch by 1 inch chunk of raw fish or a raw shrimp into the tank. As it decomposes it will release ammonia into the tank.

Option 3:
Use 100% pure ammonia.
Using a dropper, add 5 drops of ammonia per 10 gallons of aquarium water. Continue this process daily until you start to get nitrite readings with your test kit. Once you can detect nitrites you should only add 3 drops of ammonia per 10 gallons of aquarium water. Continue this process daily until you get nitrate readings with your test kit. Do a 30% water change and your tank is ready.

Option 4:
Use gravel and/or filter media from an established and cycled tank
This is the best and fastest way to go. This will seed the tank with all of the necessary bacteria for the nitrogen cycle. "Feed" the tank daily with flake food until you are getting nitrate readings. Depending on how fast you were able to get the gravel and filter media into your tank, you may be getting nitrate readings in only a day or two. There are some drawbacks to this method. Ask your source if they have recently used any copper medications in the tank. If they have and you are planning to have invertebrates in the tank you should probably not use this method. Invertebrates will not tolerate copper. Get a copper test kit to determine if it's safe to use.

Option 5:
Using live rock in Saltwater Tanks
The use of live rock in saltwater tanks has really taken off over the past few years. The reason for this is because it is one of the best forms of biological filtration available for saltwater tanks. The shape the rock is in when you get it will determine how long the nitrogen cycle will take. See step 7 on the saltwater setup page for more information on live rock.

Option 6:
Use Biospira made by Marineland. This product claims to contain some patent pending species of nitrifying bacteria that will cycle your tank in 24 hours. Some of the FishLore forum members have tried it and it sounds like it is legitimate. It is kind of expensive, but if you already have fish in your tank and they are suffering through the cycle, you may want to check this stuff out. 1 ounce of this product is supposed to treat a 30 gallon freshwater tank. There are both freshwater and saltwater versions of Bio-spira. Please let us know if you use this and if it works for you by submitting comments below.
Once the cycle has started only add one or two fish at a time. Wait a couple of weeks before adding more fish. This will give your tank the time it needs to catch up with the increased bio-load.
Speeding Up the Cycling Process
There are things you can do to speed along the process of cycling your aquarium.

Increase the temperature of your aquarium water to 80°F-82°F (27°C-28°C)
Get some beneficial bacteria colonies. Borrow some gravel from an established and cycled aquarium. If you have another tank with an extra filter you can use it. If you have a really nice friend with an established and cycled aquarium, ask if you can have one of their used filter media. It will be loaded with the good bacteria that we are looking for.
There are products on the market that claim to introduce the benefical bacteria. For more information, check out this product called Cycle Water Conditioner.
Also check out Bio-spira in option 6 above.

Sorry for the novel...

CC