Tag Archives: Aquarium Information

Helpful Aquarium & Pond Keeping Acronyms, Abbreviations

While not a complete list, these are acronyms I have found useful and many of my professional aquarium keeping friends have “thrown around”

  • A:

    AAP- An online aquarium & pond supply company, well known for their vast experience and research based information library.
    AMP – Ampere; is the SI unit of electric current.
    Reference: Ampere; Wikipedia
    AA – Amino Acid
    AC – Activated Carbon, a chemical filtration media.
    AC – Alternating Current
    Acan – Acanthastrea, a genus of large stony coral.
    Acro – Acropora, a genus of small stony coral.
    Reference: Acropora Coral Information and Care; Lighting, Amino Acids, more
    AEFW – Acropora (Acro) Eating Flat Worms
    ALK – Alkalinity, the measure of the alkaline buffering capacity of water.
    Reference: Aquarium Chemistry
    ATC – Automatic Temperature Control

  • B:

    BA – Bubble Algae
    BB – Beneficial Bacteria
    BBA – Black Beard Algae.
    Reference: Aquarium Algae Control
    BBS – Baby Brine Shrimp
    BGA – Blue-Green Algae.
    Reference: Blue Grean Algae; Cyanobacteria
    BN – Bristle Nose Pleco, Ancistrus sp, a genus of plecos.
    BOD – Biological Oxygen Demand
    BPS – Bubbles Per Second, used as a measure of the CO2 rate entering an aquarium by advanced planted aquarium keepers.
    BTA – Bubble Tip Anemone
    BTU – British Thermal Unit

  • C:

    Ca – Calcium, an alkaline earth metal. Reference: Aquarium Chemistry Complete
    Ca(OH)2 – Calcium Hydroxide, used to make Kalkwasser.
    Reference: Aquarium Chemistry Complete
    CaCl2 – Calcium Chloride
    CaCO3 – Calcium Carbonate. Reference: Aquarium Chemistry Complete
    CAE – Chinese Algae Eater
    CBB – Copper Banded Butterfly
    CBS – Coral Banded Shrimp
    CC – Cubic Centimeter
    CC – Crushed Coral, sized #2 through #5.
    Reference: Aquarium Substrate
    CFL – Compact Fluorescent Lamp
    CFM – Cubic Feet per Minute
    Cl – Chlorine
    CL – Closed Loop
    CMS – Cubic Meters per Second
    CO2 – Carbon Dioxide, a colorless gas of one carbon and two oxygen atoms.
    CO3 – Carbonate
    CRS – Crystal Red Shrimp, Caridina cantonensis
    Cu – Copper, a reddish metallic element.
    CUC – Clean Up Crew, critters that remove algae and detritus.
    CWC – Continuous Water Change. Reference: Aquarium Cleaning
    Cyano – Cyanobacteria, commonly referred to as slime algae.
    Reference: Blue Grean Algae; Cyanobacteria

  • D:

    DC – Direct Current
    DD – DownDraft, a type of protein skimmer.
    DI – De-ionized water, also known as distilled water depending upon method used to achieve the same results which is completely mieral and ion free water.
    Reference: Do Fish Drink? Use of RO/DI, Soft Water for Aquarium; Osmoregulation in Fish

  • E:

    None at this time

  • F:

    FAQ – Frequently Asked Questions, acronym of speech
    Fe – Iron
    FO – Fish Only, a type of marine aquarium
    FOWLR – Fish Only With Live Rock, reef aquaria with no corals but with “live rock”
    Frag – Fragment of coral, usually acropora, that grows into a new piece of coral
    Fragging – Similar to above, this is the act of growing new corals using pieces of other corals
    Fuge – Refugium
    FW – Fresh Water

  • G:

    GAL – Gallon
    GBR – German Blue Rams, Mikrogeophagus ramirezi
    GBR – Great Barrier Reef
    GBTA – Green Bubble Tip Anemone
    GFCI – Ground Fault Circuit Interrupter, an AC plug designed to prevent electrical shock.
    GFI – Ground Fault Interrupter
    GFO – Granular Ferric Oxide, a chemical filtration media generally used for phosphate & silicate removal.
    Reference: Aquarium/Pond Filter Media

  • GH – General Hardness, a measure of calcium and magnesium.
    Reference: Aquarium Chemistry Complete
    GHA – Green Hair Algae.
    Reference: Aquarium Algae Control
    GPD – Gallons Per Day, a measurement of flow.
    GPH – Gallons Per Hour, a measurement of flow.
    GPM – Gallons Per Minute, a measurement of flow.
    GSA – Green Spot Algae.
    Reference: Aquarium Algae Control
    GSP – Green Star Polyps

  • H:

    H2S – Hydrogen Sulfide
    HCO3 – Hydrogen Carbonate
    HID – High Intensity Discharge lighting, metal halide and mercury vapor.
    Reference: Aquarium Lighting; Complete
    HITH – Hole in the Head, a fish ailment, common with cichlids.
    Reference: Hole in the Head, HITH Disease in Fish
    HLLE – Head and Line Lateral Erosion, a fish ailment, more common in marine species.
    Reference: What is a lateral line in fish? The functions and diseases of the lateral line
    HO – High Output fluorescent light
    HOB – Hang On Back filter, also a term for a type of skimmer.
    Reference: Aquarium Filtration
    HQI – Mercury (Hg) Quartz Iodide, a type of metal halide lamp.
    Reference: Aquarium Lighting; Complete

  • I:

    I – Iodide
    IO3 – Iodate
    IR – Infrared, a type of light with a longer wave length than visible light.
    Reference: Aquarium Lighting; Complete

  • J:

    None at this time

  • K:

    K – Kelvin rating, color temperature of the light source.
    Reference: Aquarium Lighting; Complete
    K – Potassium
    KALK or KW- Kalkwasser, German for calcium hydroxide solution or limewater.
    Reference: Aquarium Chemistry Complete
    kg/L – kilograms per liter
    KH – Carbonate Hardness, a measure of carbonates.
    Reference: Aquarium Chemistry Complete
    KI – Potassium Iodide
    KMnO4 – Chemical formula for potassium permanganate.
    Reference: Aquarium Medications Part 3; Potassium Permanganate
    kWh – KiloWatt-Hour

  • L:

    L – Liters
    LED – Light Emitting Diodes. Reference: Aquarium Lighting; Complete
    LFS – Local Fish Store (or Shop)
    lm – Lumen, the unit for amount of light from a light source.
    Reference: Aquarium Lighting; Complete
    LPD – Liter Per Day, a measurement of flow (metric).
    LPH – Litre Per Hour, a measurement of flow (metric).
    LPM – Liters Per Minute, a measurement of flow (metric).
    LPS – Large Polyped Scleractinian, a stony coral, has large and soft polyps.
    Reference: Acropora Coral Information and Care; Lighting, Amino Acids, more
    LPS – Local Pet Store
    LR – Live Rock, rock with living organisms including nitrifying and de-nitrifying bacteria within it.

    LS – Live Sand, sand with living organisms including nitrifying and de-nitrifying bacteria within it.
    LTA – Long Tentacle Anemone
    Lx or Lux – the amount of light per square meter (lm/m2).
    Reference: Aquarium Lighting; Complete

  • M:

    Ma- MiliAmps
    MACNA – Marine Aquaria Conference of North America, held annually
    MASNA – Marine Aquarium Societies of North America
    MCF – Midwest Coral Farms, a well known coral farm in the Chicago area.
    MEQ/L – Milli-Equivalents per Liter, a measure of alkalinity.
    Mg – Magnesium, a trace mineral.
    Reference: Aquarium Chemistry Complete
    mg/L – Milligrams Per Liter, 1 mg/L = 1 ppm (parts per million).
    MH – Metal Halide light.
    Reference: Aquarium Lighting; Complete
    MTS – Multiple Tank Syndrome
    Mv – MilliVolts
    MW – Microworms

  • N:

    N – Nitrogen
    Na – Sodium
    NaCO3 – Sodium Carbonate
    NaOH – Sodium Hydroxide
    NH3 – Ammonia, a compound of nitrogen and hydrogen.
    Reference: Aquarium/Pond Nitrogen Cycle
    NH4 – Ammonium, a compound of nitrogen and hydrogen.
    nm – NanoMeter, commonly used as a unit for wavelength(color) of light.

    NO2 – Nitrite, a product of ammonia oxidation.
    NO3 – Nitrate, a result of nitrites converted by Nitrobacter bacteria.
    Reference: Aquarium/Pond Nitrogen Cycle
    NTS – New Tank Syndrome

  • O:

    O2 – Oxygen, a colorless, tasteless, odorless gaseous element OEBT – Orange Eye Blue/Black Tiger shrimp
    ORP – Oxidation Reduction Potential, more correctly now known as Redox balance which is the blance of both Oxidation AND Reduction, both proven to be essential for life, including aquatic.
    Reference: Aquarium Redox

  • P:

    P – Phosphorus
    PAS – photosynthetic action spectrum, another term for PUR.
    Reference: Aquarium Lighting; Complete & PUR vs PAR in Aquarium Reef/Planted Lighting; LED Wavelengths
    P04 – Phosphate
    PAMR – Professional Aquarium Maintenance & Research. An abbreviation or credential applied to persons with years of experience in professional aquarium/pond keeping and research, as opposed to the many posers lurking in Facebook groups and Yahoo Answers.
    PAR – Photosynthetically Active Radiation.
    Reference: Aquarium Lighting; Complete & PUR vs PAR in Aquarium Reef/Planted Lighting; LED Wavelengths
    PC Power Compact fluorescent light
    pH – Potential Hydrogen, a measure of the acidity or alkalinity of a solution.
    Reference: Aquarium Chemistry Complete
    PNWMAS – Pacific Northwest Aquarium Society
    PO4 – Phosphate
    pods – A popular term for Copepods
    PP – Potassium Permanganate, a chemical used in fish baths & swab as well as used to kill snails, snail eggs, and some parasites.
    Reference: Aquarium Medications Part 3; Potassium Permanganate
    PPM – Parts Per Million, 1 ppm = 1 mg/L
    PPT – Parts Per Thousand
    PSI – Pounds per Square Inch
    PVC – Poly Vinyl Chloride, used for piping and plumbing.
    PWC – Partial Water Change
    PUR – Photosynthetically Usable Radiation, another term for photosynthetic action spectrum.
    Reference: Aquarium Lighting; Complete & PUR vs PAR in Aquarium Reef/Planted Lighting; LED Wavelengths

  • Q:

    QT – Quarantine Tank.
    Reference: Aquarium Disease Prevention
    QT – Quart of liquid
    QM – Quality Marine USA, generally regarded as the premier seller of wholesale marine livestock, and now freshwater too.

  • R:

    RCS – Red Cherry Shrimp, Neocardinia heteropoda var. ‘red’
    RDSB – Remote Deep Sand Bed
    RO – Reverse Osmosis, a type of water purification that removes most contaminants & minerals, but leaves some ions.
    Reference: Use of RO, DI, Softwater in Aquariums
    RO/DI – Reverse Osmosis, followed by De-Ionization, a type of water purification to removal all minerals and mineral ions. The result is 100% neutral water with a pH of 7
    RMA – Return Merchandise Authorization. Many larger aquarium/pond supply retailers requires these be filed before returning defective, damaged, or simply unwanted merchandise. This is often a way to lower return numbers in the same way companies know that many rebate offers are not returned. I suggest to look for online businesses that do NOT require RMAs!
    RTN – Rapid Tissue Necrosis, protozoal infection of corals; can be rapidly fatal if not treated.
    RUGF – Reverse flow UnderGravel Filter

  • S:

    SAE – Siamese Algae Eater, Crossocheilus oblongus
    SAL – Salinity
    SG – Specific Gravity, a measurement of saltwater density, generally the most simple measurement of the amount of salt in a marine aquarium, although not as accurate as an Aquarium Refractometer.
    Si – Silicon
    SPS – Small Polyped Scleractinian, stony corals with very small polyps.
    Reference: Acropora Coral Information and Care; Lighting, Amino Acids, more
    Sr – Strontium, an alkaline earth metal.
    STN – Sudden Tissue Necrosis, protozoal infection of corals; can be rapidly fatal if not treated.
    SW – Salt Water or Sea Water

  • T:

    T5HO – T5 High Output light bulbs. Reference: Aquarium Lighting; Complete
    TDS – Total Dissolved Solids, the portion of solids in water that can pass through a 2 micron filter.
    Reference: Use of RO, DI, Softwater in Aquariums
    TFC – Thin Film Composite, a type of RO membrane.

  • U:

    UGF – Under Gravel Filter, a method of aquarium filtration
    UV – Ultra Violet, a spectrum of light. Commonly the UVC Spectrum is used for aquarium or pond sterilization and clarification as well as improved Redox balance by better UV Sterilizers generally found at higher end retailers.
    Reference: How Aquarium/Pond UV Sterilizers Work
    UVC – The effective sterilization spectrum of UV light energy

  • V:

    V – Volt
    VHO -Very High Output, a type of fluorescent light.
    Reference: Aquarium Lighting; Complete

  • W:

    W – Watts, a unit of power
    W/D or WD- Wet-dry, a method of aquarium filtration that is excellent at ammonia/nitrite removal, but also often results in high nitrates. Often used in the wrong aquarium applications and is often incorrectly recommended, especially for planted aquariums.
    Reference: Aquarium Filtration
    W/gal – Watts per Gallon
    WC – Water Change
    WC/PWC – Water Change/Partial Water Change
    WCMM – White Cloud Mountain Minnow
    WPG – Watts Per Gallon, a generally outdated method of measuring light requirements, however it is still useful when comparing apples to apples.
    Reference: Aquarium Lighting; Complete

  • X:

    None at this time

  • Y:

    None at this time

  • Z:

    ZC – Zoanthid Coral, a family of corals.
    Reference: Zoanthid Reef Aquarium Care & Lighting


*Aquarium Sponge Filters
These patented AAP Hydro Sponge Filters have as much as 5 times the capacity of comparable sized discount Sponge Filters (including Tetra) and are even higher capacity than the Swiss Tropical Sponge Filters.

*Wonder Shells; Regular & Medicated by AAP
The ONLY authorized online source for these unique water quality (Redox balance) & disease prevention products

Copyright 2019, By Steve Allen


Photosynthesis and PAR; Planted & Reef Aquarium

These are important aspects of both high end freshwater plant keeping and symbiotic Zooanthellae living within Photosynthetic invertebrates.

By Steve Allen

Revised 1/8/19

I will discuss each of these related aspects of Aquarium Lighting in a little more detail:


Photosynthesis, Aquarium, ReefPhotosynthesis is the synthesizing by organisms of organic chemical compounds, mainly carbohydrates, from carbon dioxide using energy obtained from light rather than the oxidation of chemical compounds.
Put another way, this means photosynthetic plants, algae, and similar use of energy obtained from light to produce cellular chemical energy and carbohydrates when combined with carbon dioxide necessary for life processes including nitrogen processing for growth.
Further Reference: Aquarium Nitrogen Cycle, Cycling

In order for the photosynthetic process to take, the organelle of the cell where light the energy to chemical energy takes place (named the chloroplast), must receive sufficient PAR (photosynthetic active radiation).
Often in aquarium environments the compensation/saturation point is not met within the chloroplast, this results in the organelle not producing the optimum amount of carbon bi-products (carbohydrates), and this excess energy will not be transferred to the host Photosynthetic Invertebrate..
The other side of the coin (more common in the ocean, tropical rivers, etc.) is photinhibition, which is the result of an excess of light energy causing cessation of photosynthesis altogether. Photosynthetic invertebrates as well as many higher plants have many light inhibiting pigments to protect themselves from tissue damage caused by photinhibition (hence the green and other colors that are often more vivid in higher light).

A myth of reef aquarium keeping is that Photosynthetic invertebrates such as corals only need the “correct” light to survive, however this is incorrect as no known animal can survive solely on light energy as there must always be a source nitrogen and other minerals for growth and reproduction.

PAR (Photosynthetic Active Radiation);

PAR, photosynthetic active radiation diagramPAR is the abbreviation for Photosynthetically Active Radiation which is the spectral range of solar light from 400 to 700 nanometers (some resources/research indicates up to 750n) that is needed by higher plants & symbiotic zooanthellic algae.
This is found from actinic UVA to near infrared. UVA is the bandwidth found between 400-550nm which is the absorption bandwidth of chlorophylls a, c², and peridinin (the light-harvesting carotenoid, a pigment related to chlorophyll).
For our discussion of PAR, near Infrared is defined as the bandwidth found between 620-750nm which is the red absorption bandwidth of chlorophylls a and c² (true infrared is beyond 750nm).

Light sources that emit mostly actinic light will often have a lower PAR (although actinic Violet-blue still occupies an spike in PAR as seen from the graph and improve the PAR of your lighting), bulbs that occupy mostly the middle spectrum (yellow-green) such as “warm White (2700K) will produce little necessary “Useful Energy” spikes (PUR) within PAR, while bulbs that produce UVA and yet more infrared will produce more important PAR light energy (as seen from the graph which shows the UVA spike and two infrared spike required for PAR).

It is noteworthy that most symbiotic zooanthellic have evolved/adapted to the lower blues of the Ocean Reefs need more of the blue/actinic spike than “higher plants”, hence the popularity of actinic lights for reef aquariums (this is true of other green algae).
However the optimum nanometer range is about 465-485nm (with some corals requiring more 420 as well), not the ONLY the lower 420nm many actinic lights produce or the more broad range many “blue” aquarium lights produce of 400-520 nm. This is where the latest technology LED lights “shine”, having a more precise 465-485nm blue as well as the lower actinic blue found in the Fiji Blue LED.
For this reason it is a good idea to have extra actinic for corals/clams that depend upon zooanthellic algae, while at the same time limiting blue/actinic in freshwater aquariums to avoid excessive green algae growth.

With he above in mind, the addition of lights that product more near infrared light spikes or the use red LED emitters does not help most photosynthetic corals and in fact some studies indicate to much red light can hinder acropora growth.
This of leaves me scratching my head why one oddly popular Aquarium Reef LED manufacturer adds red emitters to their LED fixtures (& worse, green emitters)?

Source: AquaRay LED Aquarium Lights, Lighting; Including Fiji Blue

PAR is the simplest, albeit not the most accurate way to measure light energy and quantity for the home/office/commercial aquarium. PAR is more simple to define and measure than any other forms of light measurement. However it is noteworthy that PUR is the much more important measure for saltwater reef aquariums.
The facts are you can have a light with a higher PAR be a considerably lesser PUR and thus inferior light.
Important Reference: Why PUR is more important in reef aquariums

For the aquarium keepers purpose, PAR is the number of photons per meter squared per second of light that falls between 400 nm and 700 nm in wavelength with the better PAR meters measuring the important spikes.
The meter displays these numbers in µMol•m²•sec (“mmols”), with currently accepted numbers measured as µMol•m²•sec at 50 mmol for most plants or low light corals such as Nemezophyllia, while Acropra can require PAR outputs as high as 300 mmol (any higher is simply a waste of energy/light)


To bring this concept of PAR vs. PUR to live for a real world example is a high end LED fixture compared to low grade (low PUR) fixture. Two fixtures could have the same PAR, but one could have a higher PUR. Like I’ve said in other lighting articles before…Just like there are multiple ways to add up to 10 (5+5 or 2+8), both will give you the same appearance, but one might be more beneficial to the overall tanks needs.

I strongly recommend taking a look at this additional article to help understand this concept more. It’s a shorter read, but if you digest the information in the post, it will help make this a concert idea.

PUR, PAS, PAR in Aquarium Reef/Planted Lighting; LED Wavelengths

PAR vs PUR AquaRay Readings

PAR vs PUR AquaRay PAR reading

Here is a quote from a professional in the aquarium industry that grows only SPS Acropora Coral. The hardest in the world…

Around 150 (PAR) at the sand and I could keep clams, grow sticks or anything on the sand…

This professional was not taking into account PUR, but was proving that most of what we can put to our aquariums can be grown with a lower PAR. Having a high PUR fixture will only enhance the growth of the coral or plants. A cheaper LED could have a higher PAR, but not allow for corals or plants to thrive as much as a higher PUR fixture. In this case, more PAR is required to make up the lack of PUR.

Remember: PAR varies fixture to fixture and all depends on the tech. used, mounting height, and spread. A PAR meter can be used, but it is just a tool and does not show the whole picture. It leaves out the important concept of PUR.

References; Further Reading/Information:

*Aquarium Lighting; Facts & Information

*PUR vs PAR in Aquarium Lighting; why PUR is more important in reef aquariums

*Reef Hobbyist Magazine; Understanding Lighting and Photosynthesis
3rd Quarter 2010, By Mike Maddox

Copyright 2019, By Steve Allen