What to test for?

[tico mike]

Dear G and G,

Can you guys list what you think to be the most important test kits and why??? PH, Nitrate, Alk, Calcium, Magnesium, salinity and tds. I have my own thoughts and I know after a while you can get a feel for how levels are by how happy your tank is, but what should even a long timer test for and how often. I saw Stuckeyt say he was testing alk twice a week. Also what is your thoughts on the two part?

[Graham]

It depends on what you're keeping.

For an established hard coral tank, alkalinity is the most important by far IMO. It can change relatively rapidly and the "optimal" window is much smaller than calcium or Mg. The bicarbonate component of Alk is also the limiting factor in calcification. Meanwhile, Mg is also important to monitor, since it takes tons of supplement to restore even seemingly minor depletion. It's wise to test it at least a couple times per month. I used to test Alk 2-3 times per week. Calcium never. Seriously. If you use a Ca reactor, acceptable Alk will = acceptable Calcium every time.

For starting out, I wouldn't even bother with ammonia or nitrite kits. They're useful for about 2 weeks. Give your tank 2- 3 weeks after the end of significant die-off from the rock and you'll be fine. Nitrate may or may not be something you wish to monitor. Same with phosphate, since you can assume that if there is nuisance algae growing, you have too much of both in your tank. How much is there tells you very little that you can't tell by how much algae is there. I never use them - plus, PO4 kits test only a fraction of total phosphate.

In all honesty, I never test or monitor my pH either - not continuously. If I were to notice something amiss in the tank, it would be the first thing I'd test, though. Contant monitoring (IMO) is not accurate and is a waste of money and resources. Hobby grade pH meters simply cannot be expected to stay calibrated properly for months (or even weeks) of continuous use. Try it sometime, Cal your pH meter and then re-cal a week later and see how much you have to tweak it to re-cal it. My experience has been disappointing. Not to mention that I always seem to get some kind of electrical interference using them on reef tanks.

[capman]

Originally Posted by Graham

For starting out, I wouldn't even bother with ammonia or nitrite kits. They're useful for about 2 weeks. Give your tank 2- 3 weeks after the end of significant die-off from the rock and you'll be fine. Nitrate may or may not be something you wish to monitor. Same with phosphate, since you can assume that if there is nuisance algae growing, you have too much of both in your tank. How much is there tells you very little that you can't tell by how much algae is there. I never use them - plus, PO4 kits test only a fraction of total phosphate.

And what I found back when my tank was new (it its first 6 months) and I had a persisitent vexing plague of Cladophora was that nitrate and phosphate levels were too low to measure with hobbyist kits. Seemed strange until I realized that the large standing crop of filamentous algae was probably snarfing up whatever nitrate and phosphate was released into the water (from animals, from dead algae, etc) very rapidly. (This is what led me to the ATS - algal turf scrubber. I realized that I was going to have to remove algal biomass to get that large pool of nutrients out. I also think I had a somewhat ineffective skimmer - one of the smaller ETS downdraft skimmers.)

[Graham]

Originally Posted by tico mike

Also what is your thoughts on the two part?

Just noticed this Mike.

Next time I do a reef, I will be using 2 part instead of a reactor.

[jeffie]

Originally Posted by Graham

Next time I do a reef

And how soon will this be

[mnreefgeek]

Originally Posted by Graham

Next time I do a reef, I will be using 2 part instead of a reactor.

Care to explain this a bit more Graham? I am fighting with setting my Ca Reactor back up. What two part would you recommend if I were going to the store to pick some up for your next tank?

[Graham]

Originally Posted by jeffie

And how soon will this be

No one knows...
A big one will have to wait until we have the space to accomodate a wet room - meaning a different house. A smaller one may happen in the next year or two - depending.


Chad,

I would actually defer you to Troy (stuckeyt). He's been doing the homemade recipe ala Randy Holmes-Farley and I think he recently posted something about it in the general TCMAS forum. The only hassle is tracking down 50lb bags of the salts. After that, ($50 or so) all that is needed is a 2-part dosing pump (optimally) that will set you back under $200. Set one channel to drip Alk and the other to dose Ca/Mg and you have all the benefits (IMO) of a Ca reactor (and then some) with none of the potential for disaster (no CO2 is used). No sludgy residue - and mostly known impurities (I think Randy analyzed some of them). Mix up 5 gallons of each and you're set for a long time...

[jeffie]

Here's a great video on mixing up the Randy 2-part.
http://reefvideos.com/reefshowcase_04_content.html
Click the dowflake box...

Seems like mag flake is the hard part to find locally. I heard through the grave vine that Tru green/ chem-lawn possibly stocks it. I put a call in to them today but as it being a Holiday I had to leave a message. I will let you guys know if they stock it when they get back to me tomorrow. The rest of the 2-part is easy to come by.

[mattb]

Originally Posted by Graham

For an established hard coral tank, alkalinity is the most important by far IMO. It can change relatively rapidly and the "optimal" window is much smaller than calcium or Mg. The bicarbonate component of Alk is also the limiting factor in calcification.

Why is bicarbonate the most important component of alkalinity? It's the single largest component of total alkalinity, representing some high 8x% of alkalinity. Carbonate is the next highest at something like 8%. How can you influence the bicarbonate levels vis-a-vis carbonate? Interesting...

[Graham]

Generally speaking - bicarbonate/carbonate. Depending on what you're using to replenish Alk it will vary. I believe most buffers use bicarbonate salts. Whatever form it's in, the end carbonate is the limiting factor in calcification and is also the basis of the buffering systems in marine environments. In a hydrated form in marine environments, you generally have bicarbonate if I'm not mistaken. Precipitated, it's generally carbonate.

Whether it's carbonate or bicarbonate is not all that important. It effects local pH more than anything and will likely eventually end up in the same place (as a precipitate). Because the materials that yield the carbonate are the least abundant of all the precursor required in coral skeletenogesis, it's the limiting factor - and IMO the most important to keep an eye on.

[Graham]

Maybe I misunderstand your question. When people use things like kalk, they are not directly contributing to the (bi)carbonate pool even though the OH indirectly contributes to Alkalinity. CaOH needs to react with CO2 to yield bicarbonate - buffer. Aside from it's inherently high pH (which fades as the CaOH dissociates), this is part of the reason people see a pH increase when using kalk. It uses up free CO2 (and CO2 depresses pH). It's also the reason many people find kalk unable to keep up with Alkalinity requirements in their tank - moreso than with Ca. I have also had this experience.

Back in the day before 2-parts and Ca reactors were widely used, people like Fossa and Nilson suggested bubbling CO2 into a kalk reactor to make more effective use of the solution. It would essentially give you only Ca and HCO3 along with whatever impurities were in the kalk. Probably better than "melting" coral sand. Odd that this never really caught on...

[mattb]

Right, I thought I was missing something... I think carbonic acid (dissolved CO2 in seawater) aids in determining how much carbonate is in the water and hence the limiting factor in calcification, which is then related to pH as well... fun fun... I test alk daily...