Low calcium consumption

[nmotz]

So my 40B SPS tank has been going since mid 2015 and I've noticed that I have very low consumption of calcium (modest consumption of alkalinity.)

Coral growth varies. I have two species of Seriatopora (birdsnest) that grow really well, a purple monti cap that is growing 1/4" per month, and a few others that are clearly not growing much at all (Pocillopra, encrusting montis, a different species of Seriatopora, etc). Overall coloration is maybe 6.5 on a scale of 1-10.

Ca sometimes doesn't drop at all for a week or more, then begins to slowly trickle down at maybe 1-2ppm per day. The result is that my Ca usually camps out around 440ppm. I do 2 gallon WC's every 2 weeks with normal Red Sea salt (not reef pro).

Any thoughts on why my calcium is dropping so slowly? I've read that if you dose too much alk, calcium just precipitates out of the water column. Am I preventing uptake of calcium by adding too much alkalinity? Any potential problems that might result from me dosing alk much more regularly than Ca?

 

[Usernam Invalid]

What and how much 2 part are you dosing now?
What's your Mag at?
How are you dosing by hand or with dosing pumps?
Are you dosing alk n calc at same time?

 

[nmotz]

What and how much 2 part are you dosing now?
What's your Mag at?
How are you dosing by hand or with dosing pumps?
Are you dosing alk n calc at same time?

-BRS 2 part; Alk: 3-5ml/day; Ca only as needed (maybe 5ml once per 2 weeks?)
-Mg: 1270
-Hand dosing using a syringe
-Not dosing alk/ca at the same time

 

[Rakie]

You know we need all the usuals homie.

Alk
Cal
Mag
sg
n03
p04
etc etc

My guess would be one of a few things.
1) You don't have enough light so corals aren't producing
2) You don't have enough nutrients so corals aren't producing
3) You aren't sacrificing to the acro gods often enough -- we all know that's how it feels sometimes

 

[nmotz]

You know we need all the usuals homie.

Alk
Cal
Mag
sg
n03
p04
etc etc

My guess would be one of a few things.
1) You don't have enough light so corals aren't producing
2) You don't have enough nutrients so corals aren't producing
3) You aren't sacrificing to the acro gods often enough -- we all know that's how it feels sometimes

Salinity: 1.025
Alk: 7.8 (just lowered it there over the last week from 8.2)
Cal: 440 (very rarely changes more than 5ppm)
Mg: 1270
Nitrate: 0-5ppm (API test kit, no change over the last 6 months)
PO4: don't know, don't test it. I do have a little nuisance algae on the glass that gets morning sunlight from a nearby window, but it isn't bad.
Temp: 78-79F
Flow: ~4000GPH (MP40 + nano koralia)
Reef Octopus HOB skimmer
1g HOB refugium w/marinepure spheres, media bag w/GFO

1) I'm currently boosting my lights up from where they are now to their absolute peak intensity over the next 2.5 months. I have 2 AI Primes and I would agree that in general they aren't intense enough at their current setting, but I have to adjust slowly to avoid bleaching.
2) It is true that I have generally low nutrients. Only inhabitants are a Peacock mantis and some snails. I feed 4 drops of KZ coral vitalizer and 2 drops of Selcon per day to keep the coral well fed.
3) hahahahah, that's hysterical and true also, I like it!

 

[Rakie]

It could definitely be light related. That's probably half the light you need.

I run a Radion XR15.

With all channels at 100% on a radion (UV, RB, B, W, R, G) and intensity at 100% it has a peak par of 480 6" under the surface in a 6" area. keep in mind, with ALL channels at 100%, not all of this PAR is usable. It's also important to know my Radion has twice the power of your AI Primes.

Each tile in this image is a 6" square

6" below the surface

12" below surface

18" below surface

So for this fixture, it's important to remember probably 1/4 to 1/3 of this par is unusable by the corals. And that your fixture likely puts out HALF of this power

Here is the PAR in the BRS sps aquariums in the office -- It's a little lower than I expected, especially since the tank on the left is lit by 4x24" T5 and a 250w Radium MH (BOTH of these tanks are 60 gallon cubes -- 24x24x24")

I hope all these par numbers put your lights into perspective. I'd imagine AI Prime HD's would be a nice upgrade, but if I had your tank I would run 2 Radion XR30 G3 pro's (cheap right now used), or 2 Hydra 52HD.

If you're serious about getting your tank to have a lot of high quality SPS, then you might want to add T5 fixtures to your tank. Once your corals start taking off you will need more nutrients and if you keep a mantis you'll probably have to dose those nutrients. I would also advice switching up to a nicer quality Nitrate, Phosphate, Magnesium test kit. Try Salifert, they aren't *that* expensive and knowing what your numbers are is quite important.

And finally I also have to say The lights might not be your problem :debi: sorry! But there's some information in general, and lighting is my *guess*. Keep the updates coming as things change for the worse or better!

 

[nmotz]

Yeah I remember in that video the BRS crew saying that they considered 200-300 PAR "high lighting." Based on the charts AI provides for the Prime fixture, and factoring in my coral placement, I would say that my corals get anywhere from 125-225 PAR. When I ramp my lights to max intensity, that'll go up to between 175-275 PAR, which is closer to the levels shown by the BRS video.

Having said that, it's definitely true that my fastest growing corals are placed high/central. I think once my lighting peaks out I'll have sufficient if not overwhelming light. Certainly not anything awe-inspiring but enough to create more growth.

I have Red Sea tests for everything but nitrate, but I do agree that I should phase out the API tests.

Overall, based on what you said and everything else I've observed/read, I do think it's a coral "nutrition" deficiency as a result of not enough light and available nutrients in the water. I'll get some more supplements and report back on the tank once my lighting reaches max intensity. Thanks!

 

[Rakie]

I'm gonna be honest homeboy. You will NOT, have sufficient light. Certainly not overwhelming light. Directly under your lights in a 6-8" area you can grow SPS. Your lights will barely put out 275 par 6" under water. after another 6" I'd bet it's at 175 or less -- That's also assuming 100% of that PAR is usable light to the coral (It's not.) That's additionally adding that the light range is only useful in an 8-10" area.

My light is twice as powerful as yours and I had to add an additional light as strong as your AI Prime on it's max settings with 10x better light diffusion (2x24 T5) to a 20x16x14" tank. And I'll probably add another 2x24 T5 down the road.

That means PAR wise, I'm already at 3x AI Primes on a 20"x16"x14" tank, and I probably need another light for seriously packed SPS

If I had a 40b, and I was serious about SPS, and I wanted to keep to AI Primes alone? I'd say 4 minimum. (AKA, 2x Hydra 26HD). To get truly sufficient coverage, you need 3 Hydra 26HD's. But I mean, that's if you are serious about making your tank an SPS tank. If you just want some SPS in there? You'll probably be fine in an 8" area directly under your two AI Primes at max settings.

To put it plainly -- You're running about 1/3 as much light as you need to for a full SPS tank. And unless your settings are 100% on all channels you will likely have about 100-125 par OR LESS directly under your light. And of that 100-125 par, most likely 80-100 of it will be usable light to your corals.

 

[nmotz]

Well, if that is the case I'll have to think about what type of extra fixture I need to add. I still want to see what kind of change occurs as I ramp up my intensity. Most of my corals are placed 6-10" below the waterline and my fixtures are about 8" above the water just like in the picture. My frags/colonies are all fairly tightly clustered within about 9" of the midline in my tank.

Once my lights are up to 100%, I'll see how things look. Hopefully the corals will be doing well enough that I'll only need another AI Prime or something relatively inexpensive like that.

 

[Rakie]

This is a long arse post. I hope it helps!!


Oh absolutely still get that intensity up!! No matter what you decide, the lights you have will be useful and have value to your corals health. I hope I didn't dissuade you at all, that wasn't my goal!

Not long ago when I first came back to the hobby, I thought a single XR15 would be all i'd ever need for an SPS tank. Nobody told me that single XR15 would support nice SPS 8" under the light in a 10" area only. Nor was I told they couldn't be too closely packed or they would block out each others light. So I wanted to make sure you didn't make the same mistake I did. If I could do it again I'd have gotten T5's, or at least an XR30.

As far as your current coral placement that sounds just fine! As they grow, they will compete for light and shade each other out. That's when LED's run into the most problems. When they're frags, it seems perfect.

A $0 experiment you could always try would be to put both AI Primes only 5-6" apart and group the corals around them. For a short time, this will leave one side of your tank darker -- But it's a cheap way to see how much more lighting could effect your corals (If you do this, make sure you adapt them to it. Putting 2 lights at 100% over some frags all the sudden might really freak 'em out). Like I said, it'll leave one side of your tank a little dark, but the price is right and you can gauge the results for yourself.

As for additional lighting There's a lot of cheap options out there. Don't let cost hold you back. It'll cost you more in the long run to play the upgrade game, but really if you didn't go out to dinner like the next 3x you felt like it you'd break even.

- Check out the Black Box (Chinese) LED thread; There's a ton of people who've had pretty great success using the MrAqua and Ocean Revive black box Chinese lights for SPS. They're like $100, and put out some strong light. Do your research until you feel comfortable with 'em, but 2 of those with your AI Primes and you'd be set. You can find them used for as low as $50. Of course we both know this isn't the grade A option, but it gets the job done.

- Want guaranteed lighting that wont steer you wrong? T5. It's the god mode of reefing. The ultra diffused light source cuts out the shadowing effects of lighting like LED. I saw an instant improvement to my tanks overall health once adding one to my tank. So much so I'd probably have just purchased them first if I knew better. T5's in 36" can be had relatively cheap. It'll end up being more than the Ocean Revive, but you can also find a 36" used T5 much easier than a 24".

Like my LED options, this isn't the premium grade but it's not bad. Here's a new AquaticLife T5HO Get it wherever, I was just on Amazon. With something like this you would want 2 fixture, and the bulbs they come with are crap. So yes, that's like $350 with 4 bulbs (ATI Coral+ & 3x ATI Blue+). But it's guaranteed to work. No guesswork, no fiddling with spectrums, no need to buy separate mounting gear like the AI Primes.


This is a lot to digest, and nobody likes being told they need to double their lighting investment. But lighting is possibly the most crucial part of SPS tanks. More so than LPS or Softie tanks by a lot. Acros grow close to the water, as close to the sun as humanly possible. In the wild they receive 1500-2500+ Par. Giving them 100 Par is like feeding an elephant 5 leaves for dinner.

First step -- Get your lights up, and you will likely see an improvement. Again, I hope this helps and doesn't dissuade you, you really can get good lighting fairly cheap

 

[Myka]

If your corals are pale (from not enough nutrients) your corals will bleach further if you add more light.

If the calcium is at 440 ppm, stop dosing until it drops to 410 ppm or so, and don't add more until it drops to 405 ppm. Ca is "camping out" at 440 ppm because you are dosing to maintain 440 ppm.

Which test kits are you using? You mention API for nitrate? I'd suggest you at least upgrade to Salifert for Ca, alk, Mg, NO3 and PO4. In preference, I would suggest a Hanna checker for ULR Phosphorus.

How many fish do you have? What are you adding to the tank besides salt mix? Fish foods? Coral foods? Other additives? What do you use for filtration? Skimmer? Filter pads? Other medias like carbon or gfo?

Could you post a photo of your corals? A pic tells a thousand words (or more haha).

 

[nmotz]

Thanks for your thoughts Rakie. If I could go back, I probably would have done T5s too, but I really do think LEDs are the way of the future and people do get great results with them.

The good news for me is that my tank is an "easy SPS" tank. I don't have any acros, just multiple varieties of montipora, seriatopora, and stylophora.

Myka, I do need to upgrade my nitrate test kit, which is API, but for Mg/Ca/Alk I use Red Sea tests. I understand the dosing process, it's just strange to me that only alkalinity falls regularly. To have an SPS tank and not see calcium drop for like a week at a time is odd.

I run GFO (passively in my HOB refugium), and have a Reef Octopus HOB skimmer. I don't use any mechanical filtration although I use to run an old bio wheel filter.

I also don't have any fish, just a Peacock mantis shrimp so I do add coral food since there is no fish poo in the tank. I add 4 drops of KZ coral vitalizer and 2 drops of Selcon per day. I'm also going to try ME amino acids since I keep hearing good things about them.

My corals aren't really pale or brown, they're just not vibrant. I'll get a picture tomorrow sometime. When I first put my LEDs on the tank, everything bleached, but I lowered the lights way down (~30% intensity). Then growth stopped so I'm increasing them and the corals are growing again. I'm at about 72% intensity now.

But calcium still barely moves and I'm afraid I'm going to eventually have a chemical imbalance of one kind or another that will really cause problems.