What do you measure, how often, and why?

[ejaustin]

It seems like there is an endless number of parameters that you can measure in a marine tank. That leads me to wonder what people measure, how often, and why? I have a very simple set-up, with a few fish, 2 shrimp, 1 emarld crab, assorted little hermit crabs and snails. There are a few zoos on my overflow box. They are incidental. They will need to survive in the general environment or my tank or not. (I consider their needs when I'm making adjustments to the waterflow and that kind of thing, but no special lighting. I would give them special food if I thought it would be beneficial to them.) I measure

Temp (casually, pretty much whenever I look at the tank)

Ammonia (casually with one of those little ammonia badges on the tank, whenever I look at the tank)

Test strips (about every couple weeks)

- Ammonia

- Nitrites

- Nitrates

- Alkalinity

I check the salinity with a hydrometer (although I think I will be getting a refractometer before long) every now and then. I buy pre-mixed water since I don't want to install an RO/DI unit in an apartment I hope to be moving out of soon, and I depend on the LFS to mix it properly (probably more than I should).

I measure the temp and the salinity because I know both those things are critical to all my critters' comfort and health. I measure the ammonia, nitrites, and nitrates because they give me an idea of whether the system overall is in balance. I measure the alkalinity because it's on the test strip. If it wasn't, I probably wouldn't bother.

I do keep on eye on the appearance and behavior of my animals. I've heard that royal grammas like my Emma are good "canaries" and that their color tends to fade if water quality degrades. I keep note of how often the shrimp are molting and as long as it's regularly, I feel like my calcium and iodine are probably okay for my tank and its needs. My calcium and iodine come from my water changes, so I think if they are okay, the other trace elements are probably okay, too. (Bridgett the emerald crab hasn't molted yet, but judging by her size, she's probably an adult and I don't expect her to molt as often as my growing shrimp.)

I don't dose anything and I don't have any corals.

Anyway, anyone care to share what they measure, how often, and why?

[Enigma13]

pH and alkalinity- twice a week (test prior to adding Reef Buffer and/or Reef Builder to determine dosage).

Calcium- once a week (I add Reef Complete twice a week and just want to make sure things are staying on track).

Nitrates- about every other week (just to see where they are at and determine if I need to do a larger than normal water change next time up. I usually change about 10% per week).

Iodine-every other week (dose Reef Iodide 3 times a week. Follow the mantra of "if you are dosing you need to be testing").

Phosphate and Silicate-once a month (Just to see if I have to run some SeaGel for a while).

I don't test for ammonia and nitrite with any regularity, unless I have added significant bioload. Short of something dying, addition of bioload, tank should be mature enough now to get things through the first two stages of the nitrogen cycle (setup is 9 months old). I see my temp several times a day on the digital chiller controller (set on 78 w/ 2 degree differential).

My system is a 144 gallon mixed reef, with 40 gallon sump, Euroreef 6-2+ skimmer, refugium, and about 175 # LR.

[hammondegge]

right now it is only calcium, alk, ph, and phosphate for me.

i think the helpfulness of the testing changes as the tank matures and the inhabitants change. now i have a lot of corals that are growing fast in a relatively small volume of water ~ 75gal. i also have a heavy fish load. as the mass of coral changes my calcuim consumption increases (hopefully). ph and alk are important for me to keep my calcium high.

i dont check Am, nitrite, nitrate unless something looks wrong. the corals are real good barometers for any changes that happen in the tank. if something looks odd then i will test nitrate. it has been 0 for a long time but there was a time in a smaller tank with a crappier skimmer that i would see an increase.

since i put a phosphate reactor on the system i rarely test for phosphate anymore.

of course i test salinity when mixing salt and for water changes. a water top-off almost eliminates the need to test the tank. monthly is fine for me. the refractometer is a good purchase.

I dose a homemade 2 part with a medical peristaltic pump, and put Kalk in the top-off water to support higher PH. calcium stays around 450, ph ranges from 7.8 to 8.1 and alk tends to climb ( i havnt figured this out yet) but i try to keep it around 11dkh. i add magnesium as needed, well there is another test. i test magnesium level every few weeks and adjust it then with whatever magnesium potion that is handy.

principally i believe that a tank benefits from heavy feedings, so i put a lot of food in (homemade combination of foods suitable for corals fish, and inverts). with a lot of rock, a sandbed, a lot of flow (3500gph in a 55gal), a good oversized skimmer, and inhabitants in enough variety and numbers to eat everything, i think a strong and stable ecosystem is built that keeps the tank balanced. i think my tank would consume a dead fish pretty fast with no effect to the am, no3, no4 balance.

[GKarshens]

I follow the same basic testing that hammondegge does. Except the magnesium as I haven't wanted to shell out the money for the test kit. However, John (aka the dude) recently tested it for me and it was at 1350 ppm which is about right. I dose 1/2 the recommended amount of B-ionic magnesium about once a week. I also dose 2 part B-ionic calcium/alk every other day. The other day my calcium was at 410 ppm and my alk at 9. I agree also with the theory of feed heavy and skim heavy. I have had a couple fish disappear over night in my tank. Not a shred of evidence and no ammonia spike. I highly recommend a refractometer for your water changes. It is so much easier and more accurate. I got the one that Marine Depot makes when it went on sale for $35. I have a Reefkeeper2 controller that has a ph probe so I only have to glance at it to see the temp and ph. I have had a little trouble with slightly low ph lately. 7.75 in the morning and 8.1 in the evening. I am going to put an airstone in the sump on a timer to come on when the lights go out to try to raise it a little bit.

[ejaustin]

Gabriel,

I'll be interested to know how the airstone works for you. After reading the links that Robert posted about pH, I wondered why an airstone in the sump isn't more standard practice to help optomize CO2.

When I listed what I monitor, I forgot to put pH on the list, but I do check that as well.

ej

[hammondegge]

Gabriel,

I'll be interested to know how the airstone works for you. After reading the links that Robert posted about pH, I wondered why an airstone in the sump isn't more standard practice to help optomize CO2.

ej

to increase disolved oxygen levels relative to CO2.... it is working some for me. you would think that the skimmer would do all of this that is possible but it doesnt always.

[JoeK]

I probably don't measure half as much as I should.

About the most I regularly test is calcium and alkalinity about once a week.

If something looks off or something stays closed, I'll start measuring Nitrate, PH, and salinity.

[Jynxgirl]

I only measure clacium and alkalinity about once a week. I moved and reset the tank up so keeping a closer eye then normal. I usually just watch if my xenia's hands are waving at me. If they are less then usual or not, I know something is a bit off.