Keeping Balanced SW Parameters

[JR]

When I first started researching SW tanks I felt like I enrolled in a chemistry class when I started reading about water parameters. What I later discovered it that it?s not really that hard when you focus on the basics. By taking that approach, SW is not any harder than fresh water. You just have a few more tests to complete and a few more parameters to understand.

Salinity & Temperature:

Seawater salinity is typically at 1.026 with the exceptions of the Red Sea and brackish areas. Most people set their salinity to match.

Temperature is a little different story. Based on the research completed by Randy Holmes-Farley, most reefs and a few other ocean areas that fish and corals are collected from have temperature ranges from 82-86 F. Whether or not we should reproduce this in our tank is a controversial topic. This is because our aquariums have limitations that don?t exist in the ocean. The biggest difference being how wastes are removed from the water. In our aquariums we try to do this through filtration and protein skimming, but this will never be able to match the ocean?s natural abilities. Keeping temperatures between 82 to 86 F will result in increased metabolic rates of the fish, corals, and critters which in turn results in more waste. This is why a lower temperature of 76-82F in our aquariums is better, as it helps to keep the metabolic rates lower, which in turn reduces the production of excess waste.

Alkalinity (dKH)
Alkalinity in a marine aquarium is simply a measurement of the amount of acid (H+) required to reduce the pH to about 4.5, where all bicarbonate is converted into carbonic acid as follows. I took that definition directly off the internet, but I can?t remember where I got it from. Like calcium, many corals also use alkalinity to form their skeletons, which are composed primarily of calcium carbonate. Low alkalinity can act like steroids for nuisance algae growth. Both low and high alkalinity levels can cause precipitation of calcium (meaning the calcium in the water will solidify just enough to become reduced from the water and the calcium level will drop). Low alkalinity causes precipitation in the water, while high alkalinity causes precipitation on heat sources like heaters and power head impellers.
When you dose alkalinity you will notice that it affects your calcium level by slightly decreasing it. When alkalinity is allowed to fall you will notice that your calcium will rise slightly in comparison causing an imbalance. I have found that alkalinity has been the hardest parameter to keep consistent. Check it often, and dose only as required; this will also help to keep your pH steady.

Calcium (Cal)
Corals, clams, and invertebrates (to name a few critters) will use calcium to form their skeletons and/or shells, which are composed primarily of calcium carbonate. Coralline algae will also need calcium to thrive. All of this calcium will come from the water in your aquarium. Based on the work of Randy Holmes-Farley, when the calcium level drops below 360 ppm, it becomes progressively more difficult for the corals to collect enough calcium, thus stunting their growth. Low calcium levels will affect the alkalinity level and this imbalance will put you at risk of nuisance algae. Having more than 450 ppm calcium is a waste of additives, and if you take a look below at the balanced ratio to alkalinity, a high calcium level requires a very high alkalinity level. Studies have shown that an elevated calcium level does not increase corals? growth rate or density.

Balanced Calcium and Alkalinity
The relationship between calcium and alkalinity seems to be the most discussed parameters in reef tanks, and one I had the most trouble understanding when I first started researching. Calcium and Alkalinity are not just required for corals; both calcium and alkalinity are required by a host of critters for their calcium carbonate skeletons and shells. In a closed system like an aquarium, they can quickly become depleted.

Over the years, many different ways of supplementing calcium and alkalinity have been developed. All of these have different pros and cons, and all can lead to problems if not used properly. Maintaining the balance between the two is very important (likely more important than the actual levels) as corals and other calcifying organisms take a specific ratio of calcium and alkalinity from the water to form calcium carbonate. When this balance is not maintained properly, these corals and organisms can suffer and you risk opening the door for nuisance algae to take hold

Based on the work of Randy Holmes-Farley, the below chart shows what he has found to be balance. I found it the easiest to keep my calcium level of 420 to 430 by keeping my alkalinity at about 9.6 dKH.. 


360 ppm to 0 dKH

370 ppm to 1.4 dKH

380 ppm to 2.8 dKH

390 ppm to 4.2 dKH

400 ppm to 5.6 dKH

410 ppm to 7 dKH (natural seawater)

420 ppm to 8.4 dKH

430 ppm to 9.8 dKH

440 ppm to 11.2 dKH

450 ppm to 12.6 dKH

460 ppm to 14 dKH.

[JR]

Many times I?ve read about people buying supplements to put into their tank because they thought their tank needed it and they did not test for what they were dosing. This, in the end, resulted in big problems to fix. In some cases (depending on your stocking and water change routine) you might not even have to add anything at all so never assume the instructions on any bottle of a supplement is the correct amount for your tank.

As I?m using a quality salt with only a moderate to light stocking of corals, I only have to dose a small amount. With the supplements that I?m using, I only dose 1/3 of the recommend daily amount, every second day (for both Cal and dKH). Based on my test results, that is all my tank needs. Never just follow the directions on the bottle. When/if you start dosing, start off really small (a fraction of what the bottle says) and test to determine the impact and adjust from there. If I would have only followed the directions on the bottle and not tested, I would have certainly crashed my tank by now.

Magnesium (Mag):


Magnesium both helps to buffer the pH from falling, and helps to stabilize the calcium/alkalinity balance. Without magnesium within the normal range, it is difficult to keep calcium and alkalinity at a steady proper level, and you could have swings in your PH. Natural seawater generally contains 1280 ppm of magnesium. Low magnesium can be one of the factors of nuisance algae growth. Most reef keepers agree that 1350 ppm works best in aquariums.

I prefer to keep my magnesium at ~1300 ppm before adjusting calcium and alkalinity. IME, using a high quality reef crystal will help to replenish and stabilize your magnesium. I?ve been testing my magnesium weekly for about 2 to 3 months now, but I have only needed to dose for it twice when it dropped between 1225 and 1275 ppm. I noticed that once I maintained the mag level at 1300, the dKH and Cal almost did not have any swings at all, at least as compare to what I had noticed in my tanks in the past. In hindsight, I should have been paying attention to my magnesium levels before I started dosing Cal and dKH

PH:


Just as with fresh water, natural seawater has varying levels of pH but is generally between 8.0 and 8.3 in and around reefs. This is one aspect of water parameters that can get very technical. I?ve spent a lot of time reading different articles on the topic and I sometimes can get overwhelmed by it. Changes in pH do have a big impact on processes taking place such as calcification, or the production of calcium carbonate skeletons, which is known to depend on pH, dropping as PH falls. And just as with fresh water, your PH needs to be stable for your fish and other critters to remain healthy.

IME when all other parameters are in line and stable, your PH should be stable and within (or at least close) to the normal range. Using RO water and a good quality salt will also help to develop a stable PH. At least that seems to work for me as my PH is stable at 8.1

Ammonia
Just as with fresh water, the ammonia level should also be at 0ppm. There are many similarities in the nitrogen cycle in fresh water and salt water ecosystems. In an established saltwater aquarium, the ammonia produced is used up quickly by beneficial bacteria. These bacteria?s and microalgae use it to make proteins, and other biochemical?s that contain nitrogen. The bacteria will convert it to nitrite, nitrate, and nitrogen gas.

Ammonia levels as low as 0.2 ppm can be dangerous to some fish. It should always be at 0 ppm

Nitrate
Similar to fresh water, the nitrate level in a SW tank should always be at 0ppm. One of the differences in the salt water nitrogen cycle (as compared to the freshwater nitrogen cycle) is that nitrite is far less toxic in saltwater than in freshwater. Fish are typically able to survive in saltwater with higher levels of nitrite. While some people recommend not testing for nitrite, I would say it is a critical test when cycling and in newer salt water tanks. In established set-ups (tanks that are healthy and stable for at least a year), this would be a less critical parameter to test for unless you notice that something is off in your tank.

Nitrate is often associated with algae, and is often excess nutrients. Other potential aquarium pests, such as dinoflagellates, thrive with excess nitrate and other nutrients. Nitrate itself is not particularly toxic at the levels usually found in saltwater tanks (less than 20ppm). In addition, high nitrate levels can cause the growth of zooxanthellae (with the corals), which in turn can actually decrease the growth rate of their host coral.

For these reasons, most people keep the nitrate level in there reef tanks as low as possible. A good target is less than 0.2 ppm nitrate.

Phosphate
The phosphate levels in the ocean varies greatly from place to place. Typical ocean surface phosphate levels are very low by the standards in the hobby, sometimes as low as 0.005 ppm according to the work of Randy Holmes-Farley.
Without a control measure in place, the phosphate level will typically accumulate and rise in your aquarium. It is introduced mostly with foods, but can also enter with top-off water if you are using tap water. As I use RO water, all phosphates are removed. I also use a phosphate remover passively in the sumps of both of my tanks to ensure my phosphate levels remain undetectable in my test kit.

If allowed to rise above natural levels, phosphate has been known to not only promote nuisance algae, but it can reduce the rate at which corals and coralline algae can build calcium carbonate skeletons, potentially stunting their growth.

For these reasons, phosphate should be kept below 0.03 ppm.

You can also look into strontium, iodine, and some other parameters (none of which I can even spell). I would call those more of an advanced category of water parameters.

Following these guide lines has helped me avoid a lot of the common problems that can be experienced with newly set-up tanks. Using this approach (combined with some good equipment choices) helped me avoid nuisance algae growth in both my tanks. I learned this from a friend who has a 400 gallon FOWLR with virtually no nuisance algae and coralline growing everywhere.

My 90 gallon has been set-up for just a few months under a year now. I only had some diatoms for two or three weeks and then started getting some coralline growth. I only added my CUC after about 4 months and have not seen any significant nuisance algae yet, only coralline growth.
My 120 gallon has been set-up for about 4 months now. The diatoms have been gone for a little while now and I?m starting to see coralline growth. Other than a few snails, no CUC yet. Just last week I?ve started to see coralline starting in the main tank.





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[Mugwump]

looks good JR..thanx....do you use vodka?..I know a salt water guy that doses drops of vodka....
..............

http://www.melevsreef.com/vodka_dosing.html

http://reefkeeping.com/issues/2008-08/nftt/index.php

[JR]

NO never have. Will check it out