What is Good Water Quality for Reefkeeping

Listed below are the GENERAL water parameters for our aquariums. Some species are more or less tolerant to certain factors and this should always be taken into consideration when establishing your water parameters.
Ammonina: 0ppm, anything present will be toxic for most marine inhabitants. This should only be a problem for a new aquarium which has not cycled yet.
Soulution: Introduce waste into the aquarium and let the aerobic bacteria population grow until it can effectively break the ammonia down into nitrite. Be patient as it can take up to 6 weeks for a tank to cycle properly, usually it happens in about 4 weeks. You can add live aerobic bacteria to help speed up this process. We use Turbo Start 900, which comes in many sizes, depending upon tank volume.
Nitrite: 0ppm , anything present will be toxic for coral and most fish. This second stage of waste breakdown should also only be a problem in a new aquarium or one which has lost a considerable amount of aerobic bacteria for some reason.
Soulution: Same as getting rid of ammonia. If your tank has been cycling for over 4 weeks and you still have ammonia or a good amount of nitrite you may want to evaluate how much surface area you have available for bacteria to grow on. If you only have one small piece of live rock in the tank and no bioballs (which we do not recommend for reef tanks anyways) you don’t have much surface area to harbor bacteria. You can add more surface area for the bacteria to grow upon by purchasing some more live rock; we recommend at least a pound per gallon. If you get some nice branching rock with a good amount of holes and crevices it will not only fill the tank up with less rock but it will also give your fish nice places to hide and provide good places to place or glue your corals. This addition of rock will give the bacteria more surface area to grow upon so they can have larger populations to consume the waste produced in your tank.
Nitrate: 0 ideal, anything present is not acceptable for us
Solution: The easiest solution is to do a water change to dilute the waste content, however that usually only temporarily fixes the problem. More permenant solutions are to invest in a protein skimmer and a refugium filter. In our opinion both of these pieces of equipment are necessary for a saltwater reef tank. The protein skimmer produces small microbubbles which rise through a circular chamber. Each protein molecule has a hydrophobic and hydrophillic end, one likes air and the other water, and so they immediately bond to the bubbles produced by the protein skimmer. As the bubbles rise through the circular chamber and into the collection cup the protein molecules (waste) are taken along with them and harmlessly removed from your tank. The refugium is a filter full of algae which, being a plant, eats the nitrate and phosphate and removes them from the aquarium. It is also a great breeding ground for many different pods which will provide food for your corals and fish.

Phosphate: 0 ideal, anything present is not acceptable for us
Solution: The first stages of defense against phosphates should be your protein skimmer and refugium. The last stage should be a Phosban (granular ferric oxide or GFO) reactor. The GFO media is fairly expensive and becomes exhausted as phosphates are removed from the tank. The cost of the GFO is the reason that we need the other pieces of equipment first. With a well functioning skimmer and refugium you should only have to change your GFO around once every 2 months. This setup should get rid of even trace amounts of phosphates.
Alkalinity 9-10 dkh is ideal, 8-11 ok
Solution: If your alk is low you can do a number of things to raise it. Add an alkalinity supplement or do a water change are the two easiest ways to raise it a little bit. The problem is that your alk levels will start to drop again immediately. Alkalinity and Calcium usually work against each other, meaning if you alk is a little low your calcium may be a little bit high. Checking both levels along with magnesium are very important to fixing the problem. If your magnesium levels are good but both calcium and alkalinity are low you simply need to start adding more supplements. This can be achieved in a variety of ways. A doser will pump small amounts of a liquid Part A/Part B solution into your tank. These are excellent for someone just starting out in the hobby as they are not very expensive. As you progress in the hobby and your corals begin to grow the demand for calcium and alkalinity in your tank will grow accordingly. This is when a calcium reactor begins to become a better solution to meet these growing needs. Calcium reactors are more expensive up front but the coral media (ARM) that you can run in the reactor is significantly cheaper over the long run than the Part A/Part B solution. Another method of raising alkalinity and calcium is by dosing Kalkwasser. This is very cheap but much more complicated than using the doser or calcium reactor. When i say complicated I simply mean it is easier to mess things up and I wouldn’ t really recommend it to a beginning aquarist. Kalkwasser does a good job of maintaining levels of calcium and alkalinity but in our experiences seems to have trouble raising them very much.
If your alk is high the safest way to bring it down it to do a series of water changes. If your calcium is low in addition to your alk being high then adding some extra calcium will also help to bring it down safely.

Calcium: 425 ppm ideal 400-450 ok
Solution: Calcium pretty much works the same as alkalinity but opposite. If your calcium is high and your alk is low then try adding a little extra alk to balance them out. If your calcium is low and your alk is low then try using either a doser, calcium reactor, or kalkwasser to bring both of them up as described under the alkalinity solutions above. If your calcium is low but your alk is good then you can simply add some extra calcium or do a small water change to help balance things out.

Magnesium: 1300 ppm ideal, 1250-1350 ok
Solution: If your mag is low the easiest and best thing to do is to simply add a magnesium supplement. If it is high then do a series of water changes to get it back down to the desired level.

Water Temperature: 78-80 degrees F, no more than a 2 degree change in a 24 hour period.
Solution: Water temperature is very important to keeping healthy corals. Corals come from an environment where the water only changes a few degrees a year and does it over a period of 6 months. If you water is consistently over 80 degrees there are a few things you can do to try to bring it down. Firstly you can add a fan which blows across the surface of your tank and/or filter water. This alone can help to drop most tanks a few degrees. The downside of this is your tank is going to evaporate CONSIDERABLY more water than it did prior to adding the fan. Be prepared to add a significantly greater amount of topoff water after adding the fan. If your tank is still running hot, you are going to have to break down and buy a chiller. Most hobbyists don’t want to spend the extra money for a chiller and will go to great lengths to avoid doing this, something that I just don’t understand. We put them on every tank we own and I wouldn’t personally recommend setting up a reef tank without one. They are so effective at keeping your tank running at a temperature your corals will love, while allowing you to do virtually any lighting combination that you desire without having to worry so much about heat production.

If your aquarium is running too cold simply buy a heater rated for your tank. Some people will buy two smaller heaters and put one in the tank and one in the sump. The thought process behind doing this is that if one of the smaller heaters failed in the on position it would do less damage to your tank and give you more time to identify the problem.

Salinity: 1.025 specific gravity ideal, 1.023-1.026 ok but it needs to stay at that level all the time.
Solution: If your salinity is high you can drain out up to 3% of your tank water and replace it with fresh water(RO/DI preferred) to lower it. Don’t do too much at one time or the salinity change will stress out your marine inhabitants. If your salinity is too low you can do the same thing but instead of adding fresh water you are going to add water that is saltier than your aquarium water to your tank. First take some salt and mix it in a 5 gallon bucket until it reaches the desired level of salinity. Never add salt directly to your aquarium. Again do a little at a time so the acclimation is gradual. Raising and lowering the salinity can also be done by simply doing water changes. Eventually the new water with the correct salinity will dilute the old water until the desired effect is achieved.
PH: 8.2 ideal, 8.0-8.3 ok, I listed this last as I believe it is one of the least important tests that most people tend to rely on. Meaning some tanks run a lower PH and seem to do fine. I have had many people stressed that they can’t get their PH up to 8.3 no matter how much buffer they put in and when I ask them how everything in their tank is doing they reply, “Great.” My reply is then, “Don’t worry too much about it”, something I will clarify now. I have seen quite a few tanks kept at 8.0 or even a few at 7.8, depending on the test you use, that did just fine. I would really start to worry if it drops under 7.8 PH or gets over 8.3 however, as I haven’t seen many successful reefs kept outside of those values. If your tanks PH is always low you can try opening a few windows occasionally to let some more oxygen into your home. Also check your alkalinity levels to make sure they are high enough, its near impossible to have a good PH if your alk is way off. Constant smoking can also have an adverse effect on PH. I really don’t like adding a lot of PH buffer to try to solve the problem as it will just drop back down again days after you add it and changes things too quickly for my liking. If your PH is too high i would recommend doing a few water changes until it gets back down to the desired level. I would never use PH decreaser to lower PH… ever.
TDS (Total Dissolved Solids) of the top off water your are adding to make up for evaporation: 0ppm ideal, under 5ppm is neccesary.
Solution: Get an RO/DI system or make sure whoever you are getting your water from is using one and that they regularly change their prefilters, membranes, and DI resin. I like to get my own equipment so that i can make sure it is maintained properly but I’m a pretty hands on guy. If you are less apt to do it yourself you can get a TDS meter to test any water you are purchasing to make sure the levels are at 0 TDS. The TDS meter is a handy little device and well worth the money.

These water parameters are simply to show hobbyists the levels we keep in our tanks. They have been derived from 15 years of experience in the hobby, most of which has been reefkeeping. We have had all types of reef tanks from soft corals to full SPS and everything in between. Blue Earth does not in any way guarantee or warranty your tank or marine life by following our water parameter guidelines. Again they are simply stated to show how we like to keep our water.

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