SPS won't grow

S

Sander_Bos

Member
Hello All,

I searched around the forum looking for a answer to my question, but didn't found it.
I have a few SPS corals in my tank for almost 3 months. The polyps are extended and they are (I think) doing well, but they're not growing :(
My SPS:
-Seriatopora Caliendrum (Green and Blue)
-Blue/pink Acropora
-Montipora digitata
-Acropora Millepora
-Montipora superman

Parameters:
pH: 8.3 (Sera)
KH: 8 (Sera)
NO3: 0 (Sera)
PO4: 0 (Sera)

Mg: 1500 (Salifert)
Ca: 500 (Salifert)

I know my Mg and Ca are not on the 'perfect' parameters, but does that have so much influence on the corals?

I'm running 100% LED. I have 24 Cree 3 Watt leds. 10 XP-G White and 14 XP-E Royal Blue on a 28 gallon tank.

Regards,

Sander
 
in me experience a good balance is better than exact numbers....as long as my tank keeps a balance i dont bother chasing numbers (especially stuff like ph,as long as its close and its stable..)
 
calcium and kh imbalance will cause ph to be too low. calcium multiplied by three gives correct mag and if you divide cal by factor of 42 it will give u correct kh.

sent from my galaxy s3
 
if sps won't grow there're probably 2 main reasons:
1. your light does not provide with enough PAR, my tank has simular size of yours, but i use 30x 3watts led with lenses mounted, even that, my sps didn't grow before I mount the lenses! And after I installed the lenses the sps started to grow and color changed right a way. BTW my water level is 45cm.

2.If the system is not stable, the sps won't grow either, it's true that your calcium is a bit high, but as long as it's stable, there's no problem, so try to make very thing stable!!
 
NSW has a calc of 420 and alk of 7 mag of 1280...not sure about dividing calc number by 42 to get the correct alk reading. Ive never heard that could be true but that would mean that NSW is out of balance.

As for parameters: I would suggest getting your levels consistent. IMO your readings are too high but if they are consistent the corals should be showing siugns of growth. If they have been up and down then it maybe time to try to SLOWLY change things up and drop the levels to something more in line with 450-9-1350 by doing water changes until you achieve your number. Dont do it all at once. A couple of Water changes with decreased levels should lower the parameters. Then just be diligent at keeping the levels stable.
 
Last edited:
How are the color's of your colors?

If your colors are pale (even pasty looking) and you trust your test kits, you might not have enough nutrients.

I would also look into the stability of your parameters salinity (measure with refractometer), and temp.

as stevedola mention's parameters can be corrected with water changes.
 
Im thinking that if its your sps thats not growing it may have to do with your LED set up! The par may not be ideal for sps, try to get ahold of a underwater par meter and test! LED seems to work for some people but the most ideal lighting for light loving SPS corals are MH light! You may want to move them closer to the crest of the water! MG and Ca are pretty high, try to let them come down slowly over the next few weeks to more normal levels, Mg 1350 and Ca 420-450.
 
It's funny how sps questions always create a bunch of responses that sound like guesses. I'll add my guess, your LEDs are not providing the proper spectrum needed for you sps. If you're like me, you will be pushed to the limit on patience and money before you finally realize what you were doing wrong. Be careful what you try, many people on these forums just regurgitate things they've heard from others and are completely wrong. My advice to you, only make one minor change at a time and eventually you will succeed. I did.
 
^^ this is true LOL..

Im strongly guessing that At 100% power on 24 LEDs over that size tank PAR is not the issue..

Get your parameters stable and within reccomended ranges not allowing them to drift too much will do wonders for SPS.. that last part is not a guess LOL.. Good luck
 
Dapg8gt said:
^^ this is true LOL..

Im strongly guessing that At 100% power on 24 LEDs over that size tank PAR is not the issue..

Get your parameters stable and within reccomended ranges not allowing them to drift too much will do wonders for SPS.. that last part is not a guess LOL.. Good luck
Click to expand...

YES stable parameters from my expirience are the key to most all sps problems! Most sps will adapt to their environment (flow, lighting, ect) Just keep the parameters in range and consistant and good things will come!!! Good luck
 
If the coral has good color, good polyp extension and is not showing signs of stress, it eventually will grow. It may be adjusting to the lighting or some other change in its environmental parameters. Lack of growth doesnt mean something is wrong. It may take several more weeks or even months for the coral to adjust to your tank. Patients is a big part of this hobby.
 
In my experience the stability of the params (alk, cal, magnesium) have more to do with health of corals than anything else. As long as light and water movement, temp are adequate the params are most important.

That being said, I think your params are the more important with led's than other lighting. Meaning, with less broad a spectrum the params need to be spot on. Just my theory, no proof. I just have noticed that people with awesome tanks that switch to led still have awesome tanks. People with ok tanks that switch to led end up being disappointed.
 
Well having started two threads on this and participated in several more, i can say there are some answers on reefcentral. But next time use google to search reefcentral... You get much better results.

I had the exact same issue. However how old it your tank and tell us about your lights. Also is the color good? Are you supplementing anything? Are you running pellets, zeovite, prodibio or some other carbon method? How often do you feed your fish? What kind of sand bed?


Anyway you are starving your corals. Zero nitrates will get you no growth (assuming your lights have enough par). You are running ULN as I was.... I started feeding 5 times a day and target feeding my corals every other day and once my nitrates hit .25...boom... Daily growth. Keep your nitrates low but not zero and your growth will take off... Also dose some amino acids but be careful...

Once your nitrates come up, back off on your feeding. It took me two months of heavy feeding to get them to come up...

I also have a shallow sand bed and vacuum it weekly and that helped as well to get rid of any trapped phosphates...
 
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