Another noob Chem question

[ryleary]

When first researching a saltwater tank 6 months ago, I came across this forum and thought, "I'll never get that crazy with this hobby", but, here I am, reading articles about dosing for a few days.

I was given some sps and lps from a local reefer with 1000g of frags in his basement. Absolutely amazing setup. He got me started with 7 or 8 frags, many free, for $40. He is an awesome guy who gives a great name to this hobby.

I never thought I would care about sps, reading how hard it was. But having a few and seeing a little growth and how cool they look with there little "feelers"(I do not know the term yet) out, I was hooked. I want to do this right and have an awesome mixed reef tank.

So here's my question. I picked up API tests (I know, that's all my LFS had) for calcium and kh. Little background;
45g 20g sump
Ph=8.0
Ca=340
Kh=9

All other parameters good.

Tank has been cycled with cuc for ~2 months.

No fish yet, clown pair in qt, going in next week.

I have a small frags of zoas, mushroom, lps and sps for about a month now. All seems to be doing well and growing under Chinese led except the chalice and Monti (haven't seen signs of growth)

I have been reading and it looks like my calcium is a little low especially after a since I've been doing 10% water changes every Monday since I've had the tank.

If my levels stay similar over the next week or to and I am just low on calcium, what's my best bet in raising calcium with out messing with kh or pH? I guess 8.0 pH is on the low side so that could come up too.
Sorry if this is long winded. I was just overwhelmed on the articles on this topic.
Can any seasoned veterans break this down for a noob?

Or is it wy too early for me to be getting crazy about slightly low Ca?

 

[lpslover]

You also probably want to be checking Mg and Sr, I know my corals grow way faster if I closely monitor and manage Sr levels. Also, low Mg levels can contribute to all kinds of things, including precipitation events and low pH. pH in a saltwater tank is a tricky question as it is effected by many factors including alkalinity, calcium, magnesium, dissolved oxygen/ORP, and what proportion of the alkalinity is carbonate vs. bicarbonate. Personally I don't worry much about pH provided my Alk/Ca/Mg are good. There are exceptions to this, but I wouldn't worry about a slightly low pH right now if I were you.

As to Calcium supplements, you will want to look for one that is Calcium Chloride or Calcium Gluconate based. In theory Gluconate is more bio available, but I haven't noticed a huge growth difference. The other common options for Ca supplementation: Kalkwasser AKA calcium hydroxide, or calcium reactor, will both effect other chemistry parameters, so they should not be used IMHO unless you have and use a Mg test to avoid that getting way out of balance. Quick note: combination supplements, Ca with Mg and/or Sr, can save time, but they can also cause imbalance if your particular tank is using more calcium than whatever else is in the supplement. I prefer to keep all my supplements separate and dose weekly only as indicated by water tests. Bulk reef supply has cheap and great Ca chloride.

 

[UK_Pete]

If you want a balanced calcium and alk supplement, limewater is the simplest and its very good. On the other hand if you want to raise calcium and not alk, limewater wont do that, and you need calcium chloride (for detailed explanation you need to google for 'Randys diy 2 part' and read the article once a day until you are happy you completely understand it, its far better when you understand what youre doing). You can just get calcium chloride from the LFS and follow the instructions without understanding how it works, but understanding is much better.

Alternatively you can get a packet of high calcium salt, generally the 'pro' salts are high calcium and alk. But it might be too high, so you might want to mix it with your low salt to get a medium salt mix. Still, if your corals take off and start to grow fast, just doing water changes will be a time consuming and expensive way to maintain calcium and alk.

I recommend reading Randys article, and getting the 3 components, I think BRS sell the big 3 (calcium chloride, magnesium chloride / sulfate mix, sodium bicarbonate which is alk).

Another thing is dont raise alk too high unless you know 2 other important numbers, phosphate and nitrate. These 2 are the other critical values for a reef, and I dont think anyone should hope to keep corals unless they have a decent test kit for them. If your nitrates are below about 1ppm, or your phosphates below about 0.03 (maybe a little more), then you should not raise your alk too much above 7 or 8, as experience seems to show that corals perish under these conditions. If your nitrates or phosphates are much above these levels then you will want to know about that and address it too, because much over these values and corals can do less well. You will find that these 2 numbers are the ones you keep a close eye on, apart from calcium and alk, and you will probably test for them quite regularly (most of us do, especially at first until we feel we understand the tank by its appearance, and many of us still test these weekly after 10 or 20 years of reef keeping).

If I was you I would not buy any more API test kits, as you will probably throw them out before you finish them, they are not good at low levels. Salifert is one decent make thats not too pricey. So one option would be the salifert nitrate test, and then as for the phosphate test, you have to decide how serious you want to get about the hobby. Phosphate is a really quite important parameter, and there is a very popular electronic test, the hanna 713, that allows quite accurate testing of phosphate, but its not cheap, I think about $50. You could get for instance a salifert phosphate test, but it is not accurate at levels like 0.03 ppm phosphate, which is where you probably want to be if you want to keep sps. The hanna, while not perfect, has become very popular amongst reefers and I think is generally considered the best affordable phosphate test.

So once you have the above, you should keep an eye on calcium and alk, and keep them in the range you decide you want to target, which is easy, and then it becomes about managing nitrate and phosphate. Theres lots of discussion on here about how to lower or sometimes raise both nitrate and phosphate to keep it in the best range for SPS. Theres GFO, carbon dosing, sand beds, algae etc, once again search for Randys articles on nitrate and phosphate for a primer and keep reading until you understand. Managing these nutrients really becomes an important task, maybe the main task, in keeping a mixed reef tank. Food adds nitrate and phosphate so they usually creep up at first in a new tank, and you might find that unless you keep an eye on them from the start, you suddenly start getting problems in a few months when one or both of these have got out of hand. Then you have to rush to try to lower them etc. If you watch them from the start you will gain a feel for them in your tank and be able to act in advance as they start to get above your target range, without having to suddenly come back here saying help my nitrates are 30 and my corals are looking upset! When you get a chance spend a bit of time browsing the history of the reef chemistry forum and you will find lots of discussion as to how people manage these and you will be able to decide in advance which you fancy using yourself. As a quick start tip, I think most people believe that phosphates of about 0.03 ppm, and nitrate between 0.5 ppm and 2 ppm is good. Some are happy to let their nitrates climb higher than that, but most people dont like phosphates creeping much above that number.

 

[ryleary]

If you want a balanced calcium and alk supplement, limewater is the simplest and its very good. On the other hand if you want to raise calcium and not alk, limewater wont do that, and you need calcium chloride (for detailed explanation you need to google for 'Randys diy 2 part' and read the article once a day until you are happy you completely understand it, its far better when you understand what youre doing). You can just get calcium chloride from the LFS and follow the instructions without understanding how it works, but understanding is much better.

Alternatively you can get a packet of high calcium salt, generally the 'pro' salts are high calcium and alk. But it might be too high, so you might want to mix it with your low salt to get a medium salt mix. Still, if your corals take off and start to grow fast, just doing water changes will be a time consuming and expensive way to maintain calcium and alk.

I recommend reading Randys article, and getting the 3 components, I think BRS sell the big 3 (calcium chloride, magnesium chloride / sulfate mix, sodium bicarbonate which is alk).

Another thing is dont raise alk too high unless you know 2 other important numbers, phosphate and nitrate. These 2 are the other critical values for a reef, and I dont think anyone should hope to keep corals unless they have a decent test kit for them. If your nitrates are below about 1ppm, or your phosphates below about 0.03 (maybe a little more), then you should not raise your alk too much above 7 or 8, as experience seems to show that corals perish under these conditions. If your nitrates or phosphates are much above these levels then you will want to know about that and address it too, because much over these values and corals can do less well. You will find that these 2 numbers are the ones you keep a close eye on, apart from calcium and alk, and you will probably test for them quite regularly (most of us do, especially at first until we feel we understand the tank by its appearance, and many of us still test these weekly after 10 or 20 years of reef keeping).

If I was you I would not buy any more API test kits, as you will probably throw them out before you finish them, they are not good at low levels. Salifert is one decent make thats not too pricey. So one option would be the salifert nitrate test, and then as for the phosphate test, you have to decide how serious you want to get about the hobby. Phosphate is a really quite important parameter, and there is a very popular electronic test, the hanna 713, that allows quite accurate testing of phosphate, but its not cheap, I think about $50. You could get for instance a salifert phosphate test, but it is not accurate at levels like 0.03 ppm phosphate, which is where you probably want to be if you want to keep sps. The hanna, while not perfect, has become very popular amongst reefers and I think is generally considered the best affordable phosphate test.

So once you have the above, you should keep an eye on calcium and alk, and keep them in the range you decide you want to target, which is easy, and then it becomes about managing nitrate and phosphate. Theres lots of discussion on here about how to lower or sometimes raise both nitrate and phosphate to keep it in the best range for SPS. Theres GFO, carbon dosing, sand beds, algae etc, once again search for Randys articles on nitrate and phosphate for a primer and keep reading until you understand. Managing these nutrients really becomes an important task, maybe the main task, in keeping a mixed reef tank. Food adds nitrate and phosphate so they usually creep up at first in a new tank, and you might find that unless you keep an eye on them from the start, you suddenly start getting problems in a few months when one or both of these have got out of hand. Then you have to rush to try to lower them etc. If you watch them from the start you will gain a feel for them in your tank and be able to act in advance as they start to get above your target range, without having to suddenly come back here saying help my nitrates are 30 and my corals are looking upset! When you get a chance spend a bit of time browsing the history of the reef chemistry forum and you will find lots of discussion as to how people manage these and you will be able to decide in advance which you fancy using yourself. As a quick start tip, I think most people believe that phosphates of about 0.03 ppm, and nitrate between 0.5 ppm and 2 ppm is good. Some are happy to let their nitrates climb higher than that, but most people dont like phosphates creeping much above that number.

Thanks for the detailed response! I did test for phosphate and nitrate and was at a 0 with the API tests. I have heard the API tests aren't great for the lower levels. I guess I will look into ordering some salifert to double check my numbers, and i do need a mg test. I have been ghost feeing a few pellets once every other day for the cuc, as i have no fish in there yet, so apparently they are handling that waste.It looks like I am getting some growth on my SPS, I have been feeding some marine snow once every other night and at about 50% with my chinese leds.

So thank you for the advice, I will read that article another 10 times if I have to. Its been awhile since high school chemistry. So intrigued by this hobby and so thankful for all the help I have received!

 

[UK_Pete]

I've read some of Randys chemistry articles 10 or 20 times, or at least gone back to sections I dont understand repeatedly until I do! When you eventually get it, you will find that its far easier to actually understand whats going on in the tank and what effect (and side effect) changing parameters have. Remember too if you are seeing 0 for nitrate and phosphate, that is considered ULN (ultra low nutrient), and you will not want your alk much above natural sea water (NSW) which is about 7. With ULN systems, if you go too far from natural alk levels, you can experience rapid death of corals. As far as the mag test goes btw, I dont think its as important as the nitrate and phosphate, alk and calcium. Without much coral growth, and with a decent salt, mag will not change that fast. Get the best phosphate test you feel is appropriate, a decent nitrate test, and a decent alk test imo.

 

[ryleary]

Sounds good, will do. Thanks again.