Discussion in 'Reef Chemistry by Randy Holmes-Farley' started by Randy Holmes-Farley, Sep 19, 2014.
Mr Randy holmes you have mentioned for dosing iron, ferous gloconate is a good thing, but i didnt found that .
The drag stores have ferrous sulphate.
Is it the same thing that i dose it to my tank?
I have been running Zeovit in one of my SPS systems and so far with good results. My alkalinity is usually lower than the recommended amount in your text (great text BTW). I try to keep it between (6.5 - 7 dKH) but have had it around 6.45 without any major problems (with that said I want to be clear that there is very little variation and it reached that value coming from 6.7 throughout several weeks). I dose 2 part and the way I respond to lower (or higher) than desired concentrations is increasing (or decreasing) my dosing in 10%. Every time I increase the dosing I notice a very gradual increase of approximately 0.05 / week for a couple of weeks and then it starts to decrease again. Do you guys think there is a stimulatory response leading to more use of carbonate after slow incremental concentration increases or it is just the growth speed of my stony corals?
No. It would be best to have one that was bound to an organic material like gluconate to keep it from rapidly precipitating. The ferrous sulfate would be better than nothing, but perhaps not as good as ferrous gluconate, or ferrous citrate, etc.
I'm not sure, but higher alkalinity will lead to higher demand as both coral calcification and abiotic precipitation of pumps and such increase as alk increases.
So @ phosphate @ .03 and nitrate @ 5ppm I could raise my alkanity from 8.12 to 8.5 over the course of a wk or so and be safe? Just having trouble finding the cutoff point on Alk b/w ULNS & a system w/ measured Nitrate/Phosphate like I have...
Sorry, I don't usually monitor this thread. Yes, that would be fine, IMO.
Randy, I just want to start out by saying I have never been a reader, because most literature is a hard read for me, if it's science based. I find you an easy and very enjoyable read, please don't stop writing. Thanks
Welcome to Reef2Reef and Happy Reefing.
This is now my new "go-to" reference. Thanks Randy!
Glad to hear!
@Randy Holmes-Farley is it possible for Ca to hardly depletes in a 2 YO reef tank housing hammers, torch, acans, goniopora, colony of zoas, snails and fishes?
I do weekly WC with normal red sea salt and last Ca dose was on 23 January 2016.
All 3 elements were tested using Salifert with expiry of 2018 and longer.
I can see coralline algae here and there.
Yes, when calcium and alkalinity demand is low, calcium may be replenished by so salt mixes that start with elevated calcium.
Calcium is used in proportion to the amount of alkalinity consumed, about 18-20 ppm of calcium for each 1 meq/L (2.8 dKH) of alkalinity. Alk can also be slowly depleted for other reasons (using a sulfur denitrator, accumulation of nitrate, etc.), but calcium generally is not.
Are you finding you need to supplement alkalinity?
another good thread. tagging along.
Thanks Randy for the reply; I'm just using normal Red Sea Salt with the following level of Ca, Mg & Alk:
I do NoPox dosing on daily basis so am not too sure the correlation of that dose to Ca, Mg & Alk levels.
There seems to be steady use of Alk in my system, which you can see from the chart below:
The last dose I did for Alk was on 10 February, 2016, which brought it up from 7 to 8.4 and from there onwards, you'll notice there has been a steady use.
But the odd thing is the Ca level ... the last dose I did for Ca was long time ago, 23 Jan 2016 and given there were 3 weekly WC in between that may replenish the Ca element ...
So is it possible that weekly WC adequately support my Ca level but not my Alk & Mg level?
I know I sound like a number chaser
To put it in number and not chart perspective, here is my current level (measured as of yesterday):
Mg 1,260 ppm (target: 1,300 ~ 1,350 ppm).
Alk 7.7 dKH (target: 8 ~ 8.5 dKH).
Ca 420 ppm (target: 420 ~ 450 ppm).
Salinity 1.026 SG (target: 1.025 ~ 1.026 SG).
Po4 0.25 ppm (target: 0 ppm).
No3 40 ~ 80 ppm (target: 0 ~ 10 ppm).
Yes, water changes often supply adequate calcium and not alkalinity, for the reason I mentioned.
Your demand for alkalinity is very low. Much less than 1 dKH per week, if I am reading that correctly. You'd expect calcium to drop by less than 6 ppm in that same time frame, which you would not be able to detect with a test kit.
Do you find it odd for such low demand of Alk & Ca for a 55 gallon tank housing 2 hammers, 2 acans, colony of zoanthids, goniopora, heaps of snails (turbo + nassarius) & obvious growth of coralline algae?
Those LPSs, snails & coralline surely have absorb some Ca for their skeletal growth? or probably I'm overestimating the usage of Ca in a reef tank.
Everything else ignored, coralline algae can use 2 dKH per day, but that is when it is covering everything and growing everywhere.
LPS generally grow quite slowly and provide fairly little demand. I've had two bubble corals for nearly twenty years and while they do certainly grow, it is not visible week to week.
Zooanthids provide no demand. Snails very little.
Think of it this way...
20 ppm of calcium and 2.8 dKH of alkalinity in a 55 gallon tank correspond to about 11 grams of calcium carbonate skeleton that would be deposited.
Since coral skeletons are porous, that's a bit more than 2 teaspoons of new skeleton.
To to see that drop in alk and calcium, you'd need to see that amount of added skeleton, although this can be hard to judge across many organisms.
Thanks Randy. 17 years into this hobby and you continue to educate me. Great work!
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