WATER QUALITY
Often spoken about, but what is it?
Right off, most hobbyists think in terms of Ammonia, Nitrites, Nitrates, Phosphates, Calcium, Alkalinity, Magnesium and water parameters like pH, temperature, and specific gravity, to name the top of the list. When someone posts that they are having a fish problem here on Reef Frontiers, they most often claim ‘My water quality is good.’ They don’t list the parameters and actual numbers.
Is the water quality good though? That information could indicate a water problem but water quality still doesn’t cover that list.
There is much more to water quality than just ammonia, nitrites, nitrates, calcium, alkalinity, magnesium, pH, temperature, and salinity. These are the things that can be measured by available test kits, equipment, and devices. They are important but far from all inclusive. These conditions are just a tip of the iceberg of what is in the captive marine aquarium water system.
BASICS
I’m sure other posters in Forums on water chemistry have made it clear how the basics of water quality hinge on the above list. It is true. I call it the Basics List.
THE BASIC LIST:
Ammonia
Nitrite
Nitrate
Phosphate
Calcium
Alkalinity
Magnesium
pH
Temperature
Salinity (or Specific Gravity)
But when there is a debate about what pH, temperature, and salinity is best for our aquarium, one wonders what is really meant by best? A good article to get you thinking about what temperature and salinity to keep your fishes at is this one: What are Natural Reef Salinities and Temperatures. . .. The subject isn’t as straight forward as the hobbyist would like. In the mixed aquarium (marine life coming from different waters), is there such a thing as the right temperature, pH or salinity? Nonetheless, when making a large (over 10%) water change, these three are really important to control and hold constant: How to Make a Successful Water Change.
A note should be made about measuring. How do you accurately measure these things on the Basics List? Don't use dip sticks for accurate measurements. If you use a refractometer, it needs to be calibrated to sea water. Refractometers are calibrated to sodium chloride (table salt). This is not sea water. For an accurate sp. gr. or salinity measurement, the refractometer must be calibrated to a sea water standard. THEN the hobbyist knows the real sp. gr. or salinity of their marine system. pH is best not done by a test kit, but by a pH meter. Field meters made by Hanna are not that expensive and for hobbyists with a large investment, should be a tool used for pH, rather than a pH test kit. For the others, a reliable test kit, not having reached its expiry date and stored properly is the proper choice. After a kit is opened and first used, don't count on it beyond its expiration date or 6 months, whichever occurs first. If any of the chemicals in the kit become contaminated, toss the kit and obtain a new one to use.
The reader will find many of my posts relating problems with fish(es) to the poster’s water quality. It doesn’t mean the poster’s aquarium has high ammonia, nitrites, phosphates, or anything is wrong from the Basic List although one or more of these can be the case. It means that something is wrong with the water. And that can mean one or more from the Basics and/or a water contaminant or ingredient that goes beyond the test kits and measuring devices. This is the reason I sometimes don’t bother to ask about giving me specific numbers when I can see there is a water quality issue. If the poster doesn’t want to post actual numbers, then it’s up to that person to find the water quality issue. But then, there are still some things that are not in that Basics list. What are those other things and how do you know the quality is ‘off?’
Before I leave the topic of test kits two more important things: Just because you measure a thing doesn't mean everything else is okay. What I mean is that you can measure ammonia for example, but you are only measuring ammonia. If you don't take the time to measure everything you need to measure, you can't say anything about the other chemistries. Second and last is that what we do measure is only a very small fraction of the ingredients of salt water, not to mention a few thousand of other things that may be there from source water and home-source poisons/pollutants.
NATURAL ORGANICS
This component of the marine aquarium water is the most common untested ‘pollutant.’ I call them "Natural" because they are the organics that are part of the chemical processes normally found in the aquarium. The "Unnatural Organics" are the POISONS (see below). Natural Organics come from invertebrates, corals, fishes, pods, benthic creatures, microbes, live rock (cured and uncured), and all heterotrophic aquarium marine life. It is added to the aquarium by the hobbyist through feeding and other additives. Maybe a friend decided a little food is good so more is better. Maybe the aquarium keeper has not been properly trained on how to feed the life forms. This is usually classified into the general category of dissolved organics.
If these organics are not kept low in concentration, they encourage microbial growths (e.g., diatoms, bacteria, micro algae, etc.) in large numbers, called a ‘bloom,’ that interferes with the health and/or metabolism of some marine life forms. Marine life signs of water quality being off include: Signs of: hair algae; micro algae; cyanobacteria growths (red slime algae); dinoflagellate (zooxanthellae) growths; brown algae; diatom growth; slimes; off-colored patches on rock or substrate that are not coralline; etc.
Signals of high organics include: a yellow tint to the water, a surface (oily) sheen, bubbles linger rather than 'pop' as soon as they are formed, cloudy water (with bacteria), swings in pH, fish breathing faster than normal, and strange behavior or health of fishes (especially fish with bacteria or 'burn' blotches. In particular high organics and thus high bacterial count can cause the fish to contract a cloudy eye now and then or suffer bacterial infections, or virus infections (like Lymphocystis). I have witnessed on more than one occasion that a tank of fish, in high levels of dissolved organics, act irritated. They may actually scratch or flash more than normal. So when an hobbyist complains their fish has a cloudy eye or the cloudy eye comes and goes, high organics is something to investigate as well as other causes of bacteria population blooms.
Most captive marine fishes can defend themselves against a bacterial infection, but not when the numbers of bacteria are huge compared to their normal (ocean, sea, reef) environment. So keeping organics to a minimum to prevent bacterial blooms is essential to good water quality and the health of the captive marine life forms. Besides irritating and causing problems with fish health, another down side to large populations of bacteria is that they consume oxygen and produce carbon dioxide causing swings in the pH and robbing fishes of their oxygen. This is about the only routinely tested feature that may lead one to consider the possibility of there being a higher-than-desired concentration of organics: oxygen content.
Probably the best known organic water quality controls are the use of activated carbon, the use of a protein skimmer, and water changes. To some extent, a refugium can be a means of reducing dissolved organics when the life forms are chosen that utilize organics. However, a typical refugium is usually a source of organics! Another add-on or marine aquarium feature is the deep sand bed. They act as an organic reducer.
The protein skimmer does not remove all proteins from salt water. There are certain kinds of organics that are not efficiently removed by the protein skimmer process. These include several of the fatty acid and lipid organics. So besides keeping the protein skimmer clean and working at its maximum ability (see below), the hobbyist wants to use some organic adsorbent/absorbent material, such as activated carbon, to remove those other organics that are not efficiently removed by the skimmer. Should everyone use a skimmer and activated carbon? No. Keep reading.
Skimmer sizing: The optimal target is to have a skimmer that will process about 1.5 times the volume of water in the entire marine system, every hour. As an example, for the average bio-load system with a total volume of 115 gallons, the skimmer should process no less than 160 gallons per hour. There is no ‘standard’ skimmer rating system, unfortunately. Most manufacturers will stretch their product’s skimming ability, so it’s hard to give advice to the hobbyist on what to buy. If the processing gallons per hour is not specified by the manufacturer, then in general, I recommend the hobbyist purchase a skimmer rated between 2 and 3 times the volume in the system. So if the system contains 115 gallons as in the above example, the skimmer should be rated for about 250 gallons. After its choice, it must be operated to its full efficiency. Don’t reduce the recommended pump flow; keep the air intake clean and open; keep the bubble chamber walls clean and the collection cup clean. The skimmer only works best when it is clean. How often to clean? No less than every other day. Daily cleaning is recommended by me for a high bio-load system (see below).
The organic adsorbents/absorbents: If the hobbyists wishes to use activated carbon in addition to using a skimmer, I recommend to use about 1 pound dry carbon for every 100 gallons of system water. In addition, the choice of carbon should be one that doesn’t release phosphates or other materials into the water. So, in the above example, the hobbyist will want to use a bit more than 1 pound of dry activated carbon. I further advise that it be used constantly for only about 10 to 14 days (14 in low bio load system; 10 in high bio load systems). Then remove it and discard it. Leave the system without carbon for another 10 to 14 days, then put fresh carbon back in. Continue this cycle. The reason for this is that old carbon stops adsorbing significant quantities of organics and just continues to remove trace elements. With the use of a skimmer, the carbon is capturing organics for up to 2 weeks and then slows down to the point where about the only things being removed from the water are trace elements. Also, the carbon doesn't have to be constantly there to provide the needed export. The on/off use of the carbon is quite satisfactory, in general, for a normal bio loaded system that is also using a skimmer. There are now a few choices of organic absorbing material. The hobbyist wants to know that is absorbs fatty acids and lipids for sure, and that the material doesn’t release anything into the water, including what it has absorbed.
Water changes: Water changes can correct a world of wrongs. Diligently performing water changes is an important means to export excess organics that the other means leave behind. Water changes over 10% must be made such that temperature, salinity, and pH are controlled. Please read this: How to Make a Successful Water Change.
Deep sand bed (DSB): An optional approach, one not needed for a FOWLR system, so I’ll not cover it here. However, it should be pointed out that the properly established DSB reduces organics in the system. Most notably, it converts some nitrates to nitrogen gas and other chemicals.
Skimmer and adsorbent/absorbent always needed? No. A system with a low bio load can probably get away with either a skimmer or carbon. A real low bio load system (one with no ammonia-nitrogen waste producers – like in a reef-only system) may not need either. [NOTE: A low bio-load doesn't always take into account protein concentration. For instance many marine life forms release organics into the water as a means to defend their territory or inhibit competitors. They may not create typical ammonia-nitrogen wastes which is what 'bio-load' is usually connected with.] Also, if the hobbyist is doing very large and frequent water changes, this is a fine alternative fast export of organics and a skimmer and carbon may not be needed at all. A medium bio-load and nitrogen waste producing system that is being fed by the hobbyist should have at least one or the other and preferably both. The heavy bio-load system, like in a FOWLR system, should use both organic controls.
POISONS and UNNATURAL ORGANICS
This is the second largest source of pollutants that prevent the water quality from being really ‘good.’ This includes oxidizing metal (rusting) equipment and connections, glue, uncured or improperly cured resins, decorations, rocks (trapped metals, etc.), unusual substrates, condensation from hood and lighting equipment, foods (some contain pollutants), fumes and mists (paints, chemical household cleaners, cooking, etc.), a 'reliable' source water gone bad, and intentionally added things (that don't belong in the water). In this last group are children that think ‘Nemo' might like some Cheerios or candy. Sometimes it’s just an adult who thinks that if a little is good, then a lot is better. Unfortunately, I've known two cases of intentional sabotage.
The system and its inhabitants react to these in many different ways. Sudden death of sensitive fishes. One death or one fish being affected doesn’t eliminate the poison pollutant possibility. When only one fish is affected, it reduces the chances of it being a water pollutant, but doesn’t eliminate it. Different kinds of fishes have different pollutant tolerances, and even within a species, different fish have their own personal threshold tolerance to pollutants.
Finding the source and type of pollutant requires a lot of detective work on the part of the hobbyist. Maybe the hobbyist left the system care to a friend or neighbor while on vacation or on business travel. The keeper can be interrogated, but unlikely to admit to any wrong doing.
Determining there even is a pollutant in the water can be challenging. How to find something that cannot be tested? Water clarity; microbe activity; live stock reactions (from signs of stress, irritations, diseases, to death); and coloration are about the most often encountered signs. Fluctuating and unexpected pH readings can indicate a pollutant that affects the buffering ability of the water or directly affects the pH of the water. Watching this water feature closely is important and the hobbyist becomes weary of being diligent after many moons have passed being in this hobby.
Sometimes a pollutant shows up from a source the hobbyist previously determined was okay. The most common of these is a shift in source water quality. A DI system can expire and fail to provide the pure water previously expected. An RO system can fail from damage to or age of the membrane. Checking the water source is important, especially before taking the recommended (see below) corrective action. Tap water today is found to contain human antibiotics, recreational drugs, pesticides, fertilizers, etc. The RO/DI treatment process is only as good as the quality of the tap water it is processing. Everyone using the same RO/DI system in different geographical locations in the country can actually produce source water of differing quality. A lot depends on the starting water quality as to the quality of the treated water. See: Source Water.
The best thing to do when there is a chance of a poisoning, is check the quality of the source water, then use the best source water to perform a very large water change. Over 60% of the entire system water needs replacing with newly prepared salt water that is not polluted. Special attention needs to be given that the water change is done properly. See this: How to Make a Successful Water Change
MATURING AQUARIUM
Many new marine hobbyists don’t understand that a new aquarium is going through many changes (chemical and biological) that are not measured by test kits. Sometimes the problem with a particular marine life form is that the aquarium hasn’t settled down. The water quality progresses through unseen changes until the aquarium matures when these changes are less frequent and less pronounced. I won’t cover the mature aquarium in this post (again), but refer the reader to these other posts:
The Secret Cycle
The Mature Aquarium
It’s worth pointing out here though, that signs of an immature aquarium include microbe activities, like ‘brown algae,’ slimes, red algae, etc. Fish, corals, and sessile invertebrates should not be added to a system showing any of these signs of immaturity.
The fix is simple. Give it time and patience. Sort out the source of excess nitrates, silicates, and/or phosphates, and give the system time to settle.
BALANCE
Just because the marine system is FOWLR doesn't mean the hobbyist can ignore the need for chemical balance. By this I mean the ratio between calcium, alkalinity, and magnesium. Snails and the coralline algae are, minimally, dependent upon the proper balance of these components.
To over simplify the concept -- It is the goal to keep enough carbonates, calcium and magnesium dissolved in the water at the right pH, so that dependent marine life can find it easy to precipitate (take out of solution) what they need to make their calcareous shell, skeleton, etc. On the other hand, the hobbyist doesn't want the precipitation of carbonates (the infamous milky cloud!
) in the water. This requires a balance.Although the hobbyist is told to keep pH, alkalinity, and calcium within a certain range, it is AS IMPORTANT to keep them in balance, within that range. Before the hobbyist should be concerned about pH, these components must be put into balance. These three components control the pH through their buffering action. Following is a suggested balanced relationship between these three for a FOWLR marine system:
Calcium - - - Alkalinity - - - - Magnesium
(ppm) - - - - dKH - meq/l - - - (ppm)
410 - - - - - - 7.0 - - 2.50 - - - - 1300
414 - - - - - - 7.5 - - 2.67 - - - - 1300
417 - - - - - - 8.0 - - 2.35 - - - - 1350
421 - - - - - - 8.5 - - 3.03 - - - - 1350
425 - - - - - - 9.0 - - 3.21 - - - - 1350
428 - - - - - - 9.5 - - 3.39 - - - - 1375
432 - - - - - -10.0 - -3.57 - - - - 1375
435 - - - - - -10.5 - -3.75 - - - - 1400
439 - - - - - -11.0 - -3.92 - - - - 1400
From the above the hobbyist should be able to deduce that if the calcium concentration isn't between 410 and 440, then the marine system is not in balance. When the calcium is between these numbers, then there needs to be the corresponding alkalinity. Hobbyists running calcium in the 300's ppm and a (for example) 'recommended' alkalinity (between 7 and 9 dKH) have a FOWLR marine system water that is out of balance and thus, not top water quality.
If you need help in determining how much of what chemical to add to achieve the above balance, then you need to go to this site: Chemical Calculatorhttp://home.comcast.net/~jdieck1/chem_calc3.html[b. At that home page, click on the button labeled, "Traditional." This gets you to a calculator which balances the three components when you insert two. You can choose the type of chemical you will use to make the adjustment and the calculator will help you to determine how much of that chemical to add. BUT the adjustment must be small (read on below).
An imbalanced water chemistry can cause the pH to be out of control. The pH, alkalinity, calcium, and magnesium are all connected to one another. (See: A Simplified Guide to the Relationship Between Calcium, Alkalinity, Magnesium and pH by Randy Holmes-Farley - Reefkeeping.com). As the hobbyist chooses the higher alkalinity concentrations from the above table, the pH generally goes down to accommodate keeping the would-be precipitate of carbonates in its dissolved state. An incorrect or fluctuating pH (even as little as 0.05 pH units for some fishes) causes a great deal of stress to the fishes -- more than a shift in salinity.
Further, an imbalanced water chemistry can cause hardening or clumping of some substrates, precipitation of carbonates in plumbing and pumps (thereby restricting flow), the slow grow or death of calcareous marine life, and the wrong kinds of algae to bloom or take over.
Simply slowly bring things back under control. Make chemical adjustments to bring things back into order. I usually recommend no change greater than 30 ppm Calcium, no change greater than 1.5 meq/l Alkalinity, and no change greater than 50 ppm in Magnesium in any 48 hours for a FOWLR system. For two reasons: First it can take up to 48 hours for the effects of a change to become 'measurable' and second, everything should be done slowly. Also, check the salt mix that is used to be sure it is balanced. If it isn't, then you'll routinely need to adjust the salt water before performing a proper water change. (See reference above on water changes). So, this means: Make your small chemical additions to effect a change; then wait 48 hours; then test kit measure the new numbers; then continue on with another small change; wait 48 hours; then test kit measure the numbers; etc., etc. until the chemistries are in balance. When balance is achieved, now direct your attention to the pH.
Take note though. . .Precipitated carbonates will not redissolve even when chemical balance is restored. Plumbing, equipment, etc. need to be taken apart and manually cleaned (with a diluted vinegar solution) to remove calcareous precipitates. Clumped or hardened substrates will need to be removed in order to prevent oxygen and water from entering the substrate and avoid anaerobic bacteria producing hydrogen sulfide.
And before I leave this topic an important reminder: Water changes don't make the water balanced. Artificial salt water has a wide range of calcium, magnesium, and the ingredients that make up alkalinity. Each manufacturer has their own 'ratio' of ingredients. To maintain the reserve of these chemistries at the time of a water change, check the new salt water you make up to be sure: 1) the chemistries are high to maintain a reserve, and 2) they are balanced.
CUSTOM QUALITY
This last consideration has to with the preference of the life form. Maybe the marine life is too close to the light or too far away. Maybe the fish prefers water of a higher pH or higher salinity. There are some water quality considerations that are related to the marine organism being kept captive. Most hobbyists are familiar with the requirement for very low nitrates when certain corals and invertebrates are kept in the display aquarium. Similar special needs are sometimes required by other marine life forms. This is usually something we don’t worry about, but if the hobbyist is properly prepared before the acquisition of the life, then it may be apparent what conditions it comes from and what conditions it requires. If those conditions aren’t provided, the life becomes stressed which can lead to illness or death. This article (listed above) gives some idea of how different marine life expects different conditions: What are Natural Reef Salinities and Temperatures. . .
WHAT IS THE WATER QUALITY OF YOUR SYSTEM?
Don’t be too quick to answer, ‘Good!†It’s a big picture. The answer goes beyond test kit measurements so before answering the question with ‘water quality is perfect because all the parameters are perfect’ remember the test kits and devices only look at the tip of the iceberg!
After the test kits show the water is chemically where it should be, then there should be no nuisance marine life out of control. Signs of: hair algae; micro algae; cyanobacteria growths (red slime algae); dinoflagellate (zooxanthellae) growths; brown algae; diatom growth; slimes; off-colored patches on rock or substrate that are not coralline; etc. indicate less than excellent water quality. Another sign of less than good water quality is when your fish or several fishes show signs of bacterial attack, or some fishes that are known hardy fish, just won't live long in your marine system.
At any time a poster wants me to review the water parameters and test kit results (Basic List) then you’ll need to post the exact numbers AND the marine life in the aquarium. If the poster just says, ‘They are perfect’ then I’ll assume they are unknown!
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