Discussion of the Week(s): Test Kits!

[Geoff]

Which ones do we really need? what make a test kit a good one? What do LFS test for? is this enough?

G~

[tims]

heheh good question geoff.
ther are so many kits out there!
NOw aday you can test for about everything.
NO3 - Nitrate
PO4 phoshpate
Ca Calcium
PH
ALK - alkalinity
NO2 - Nitrite
NH3/NH4 - ammonia
iodine

a lot of kits have some or most of these above but i have not see any that covers them all.

[Casey]

Tim you forgot Silicates

[VWD]

Well I think the LFS are only testing PH and Nitrates and maybe ammonia if You take Your water sample to them, I have never done it so can't say for sure.

[tdwyatt]

Magnesium once a month.

If you're not supplementing Iodine, there is no need to test (and you should NOT be supplementing it)


Once the tank finishes cycling, there is no real need to test regularly for ammonia or nitrite, but you need the kits around for those times when things don't look right. This would be hard to define for folks new to the hobby, but after a year or so, most folks can look at their tanks and tell that something is amiss when things are not right. Realistically the same is true for silicates, although you need a TDS meter for your RO/DI to tell when your top off water is starting to slip in quality.

Quaity kits are those with definite endpoints for determining results rather than depending on subjective means of determining the actual value. This would be something along the titration metods like those used by Salifert as opposed to color matching for an indicator dye. Most folks have a great deal of difficulty telling different shades of pink apart, and even those that normally would be really good will have their subjectivity determined by the level of lighting in the room, the presence or absence of UV light from the aquarium lights, the background against which the color matching is performed, even the tester's level of nutrition. Although most folks have differing levels of color-matching ability, almost everyone can tell the difference between clear and purple, especially when one drop determines the color change. This reduces the error introduced by subjective determination of the results to almost zero if the test is performed correctly (within the precision of the test kit),

Accuracy of methodology is especialy an issue when dealing with SG testing, as the precision and accuracy of most swing arm hydrometers is always highy suspect, and any variance from the norm should be confirmed with a refractometer prior to making any big changes in your system's salinity.


JM2CE


Remember today our brothers, sisters, fathers and Mothers that gave their lives in order that we may enjoy the fruits of liberty.

[tims]

now tom you said that we should not be adding Iodine,
why is that? What about the people who say that this coral or that coral looked bad until i started to add iodine?
( playing DA here)

[craigGP]

"what should we be testing for?"

anything that is dosed into the tank. never dose anything unless you have a test kit to monitor the levels. the instructions on the bottle are a rule of thumb to let you know about where to start. its up to you to determine your tank's needs and adjust the dosing rate. rate of consumption of trace elements largely depends on what you have in your tank. many of the trace elements can be maintained by regular (weekly) water changes unless you have a very high demand bioload.

[VWD]

That is what I think if You don't test for it don't add it, trace element I think can be taken care of with regular water changes . I have to say that I have never had a BB. SPS tank like casey and others so I am not sure of what they may have to be adding or testing for .

[BigDaddy]

with additives I have learned how much my tank requires each day... so I only test when I change my water which is every week.

[BigDaddy]

Originally Posted by tdwyatt

Most folks have a great deal of difficulty telling different shades of pink apart

you got that right! I might as well not even test my ph anymore because when I do about all I can tell is it's 'somewhere on the scale'

[tdwyatt]

Originally Posted by tims

now tom you said that we should not be adding Iodine,
why is that? What about the people who say that this coral or that coral looked bad until i started to add iodine?
( playing DA here)

For folks that never do water changes, this is prolly true.


The biggest issue with supplementing iodine/iodide/iodate is that the tests usually only detect one type of iodine ion, so there only a general reflection of how much iodine is available to the tank. Amounts of each ion can vary depending on conditions within the tank, so there will not be a fixed ratio for all conditiions within the system. Treating iodine supplementatiion as a "More is better" substance makes for just as many "I added iodine to the tank and all my(fill in the blank) shriveled up and died" as there are "I added iodine and my tank immediately improved" situations. Many folks say that the addition of iodine made their corals all extend their polyps more fully. This is not necessarily a healthy response, and can occur simply as a response to the presence of the iodine in a feeding-type response. For some species of corals, the physical presence of small plastic beads or fine sand granules can trigger the same response, but I don't think that we should be supplementing fine sand storm additives as a coral supplementation. If you want to see your corals extend their polys, chum the water with a little brine shrimp thaw juice. This is loaded with phosphates and will definitely cause polyp extension, but it is not a good additive for either coral calcification and growth nor for the preventative measures we take to reduce the blooms of nuisance algae.

The need for iodine in most organisms in the ocean is quite small, mostly available as a micronutrient in a non-limiting excesses in the ocean, concentrated in a few organisms (primarily macroalgae) and primarily needed for crustaceans for exoskeletal integrety, STILL at micronutrient levels. Rather than go into depth about the topic, I will direct you to the chapter in Frank Millero's Chemical Oceanograpy on "Micronutrients in the Oceans" starting on page 323.

Originally Posted by Chemical Oceanography by Frank Millero

...The most important micronutients(for phytoplankton)are nitrogen and phosphorus. Some organisms (diatoms) have siliceous frustules and require silica. Although other elements such as Fe, Mn, Cu, Zn, Co, and Mo are also essential for growth, it is generally thought that growth is not inhibited or limited by the concentration of thes metals. An exception for certain waters may be Fe and Mn. In additiion, certain organic compounds, such as vitamins, are necessary for growth.

Although the chapter primarily discusses nitrogen, phosphorus, and silicon, it does present information of the ratio of availability of elements in ocean waters to the metabolic need , an interesting read for those of you who are into this topic. In addition, concentratiions of Iodine in the ocean are quickly sequestered by macroalgae and misc other biological mechanisms, and is abiotically lost from the ocean via photochemical oxidation to form atmospheric gaseous iodine molecule at the rate of 4 x 10^17 gms/year. The concentratiion of all iodine ions in seawater is around 0.06 PPM (0.06mg/l or 0.06 mcg/ml )

Originally Posted by Bill Rivers (from another nameless BBS for reefs)

Dear reefkeeping folks:

You may recall in a recent post I described the following from the Merck Veterinary Manual:

While studying tonight in Textbook of Veterinary Internal Medicine, I found the formulation for Lugol's solution:

5 gm iodine with 10 gm KI per 100 ml of solution, yields 6.3 mg iodine per drop.

Since 5 gm/100 ml and 10 gm/100 ml approximate a 5% and 10% concentration, it appears that "strong iodine solution" and Lugol's solution are essentially the same. According to Fossa and Nilsen (The Modern Coral Reef Aquarium), natural seawater iodine concentration is approximately 0.06 mg/L (eg, 0.06 ppm). Recall from my previous post that elemental iodine is bacteriocidal at 50 ppm. Overdosage of iodine in mammals causes toxic effects, and while I have seen no descriptions of pathology caused by iodine overdosage in reef systems, it is reasonable to assume that iodine overdosage would be toxic to reef animals also. Many authors of reefkeeping texts do warn that this is a concern.

What this leads up to is that if we use such strong iodine suspensions for iodine supplementation in reef aquaria, we should be careful. If we add too much, we could be killing beneficial denitrifying bacteria, and potentially causing harm to the tank inhabitants directly. Here is an example based on a 100 L tank, which approximates my 30 gallon office tank (1 USA ga. = 3.8 L; 100 L = 26 ga.):

• 100 L x 0.06 mg/L x 1 drop/6.3 mg = 0.95 drops
• 1 drop of Lugols would produce 0.06 ppm in a 100 L tank if there were no iodine in tank at time of dosing.
• 100 L x 50 mg/L x 1 drop/6.3 mg = 793 drops
• 793 drops x 1 ml/20 drops = 39.7 ml
• 40 ml x 1 tsp/4ml = 10 teaspoons

To reach bactericidal 50 ppm if there were no iodine in a 100 L tank at time of dosing, you would have to add 10 teaspoons of Lugols. So, it seems unlikely that a person could knowingly add enough Lugols to reach bactericidal levels, since the usual label dosage of KI solutions for aquarium use is 1 tsp/50 ga. tank 1-2 x week.

I have the Salifert iodine test kit, which provides a positive result when 0.2 ppm is present as a warning against overdosage.

100 L x 0.2 mg/L x 1 drop/6.3 mg = 3.1 drops

3 drops of Lugols would produce 0.2 ppm (Salifert positive test for overdosage) if there were no iodine in a 100 L tank at time of dosage.

This means that the difference between normal seawater iodine concentration and overdosage as measurable by Salifert testing is only 2 drops (1 vs. 3 drops) in a 100 L tank. You can see that if a person added the typical 4 ml (80 drops) of KI solution, you could exceed the Salifert overdosage level by a factor of over 20. I would therefore suggest that when using strong iodine solutions such as Lugols it would make sense to monitor the resulting iodine level in the tank.

Food for thought. Best wishes. Bill Rivers, DVM, PhD, DACVR

Further reading:

Iodine losses to atmosphere and ozone effects

numbers on Iodine concentrations in available products and toxicities expected

Study opn halogen recycling in the ocean

[Viv]

ok, I'll bite...why shouldn't you be adding iodine to the tank?

[Viv]

ok, your post popped up the same time as my bite...anyway what about loss by the skimmer, and uv sterilizer and lights and stuff...do we lose elements with all these pieces of equipment and are salt mixes the true replacement?

[wharyat]

When I first started out on SW, I was adding all sorts of supplements, without testing. I think I got away with it because I never did any WC's, in the long run (about 6 months of adding) I came out with a horrible cyano outbreak, due to all the factors, no WC's, to much feeding, supplements. All I add now is kalkwasser for my calc, but I test for it. Salifert tests are some of the most accurate right now.

I test weekly;
Nitrate
pH
Alk
calc
*EDIT: and salinity (very important)

Monthly I test;
ammonia
nitrite
magnesium
copper
phosphate

[Viv]

?Do all Salifert tests change color ie pink to purple with a drop? Cause I'm one of those who really has a hard time telling shades of pink...and truthfully, it does change a shade if I check in room light or daylight!