Help! Slow growth

[Clownguy]

I have always had slow growth in my tank, but I figured it was probably because of the 20K light I use. For the last year and three months I have been using 14K and 10K bulbs but my growth was still slow. So today I went and bought new salifert test kits tto see if some of my parameters were off.
Results were as followed:
Ca: 495
Alk: 11.2 dKH or 4.0 meq/L
pH: 8.38 - 8.32
N03: 0
NO2: 0
Ammonia: 0
Salinity: 1.024
Mg: 1440 ppm

The specifications on the tank are it's a 150 gallon pentagon, 45 gallon sump/refugium with chaeto Nautilus skimmer, Koralin 1503 Ca reactor with second chamber, 3 - 250 watt pfo HQI ballast with 2 20K radiums and 1 10K aqualine busche bulbs, Ice Capp 660 ballast running 4 24" URI actinics. Lights are on for 8 hours a day with the VHO's on for 10 hours. I run carbon 24 hrs a day and the effluent from the reator drips into my skimmers body. Top off and water changes with RO water using Kent salt. The only thing I dose is Tech M and I am thinking about stopping that. Should I and how do I bring down my Ca and Alk and Mg? Turn down my drip rate on my reactor or shut it off all together for a while? Any help would be appreciated.

Thanks in advance,
Chris

 

[steve-s]

Your chemistry is way too high for healthy growth of most scleractinians. Ca has no benefit above 420 ppm and in most cases will result in an uhealthy colony. While alkalinity on the higher side of NSW can be a benefit, I think 4.0 mEq/l is pushing it.

What specific corals are we talking about here?
What if any growth have you noticed and is it thick and lush (meaty) or thin and sparse?

As far as lighting, anything above 10K will usually result in sacrificing growth for visual appeal. The higher the kelvin gets, the slower the growth. Another factor you have not mentioned is phosphates. It is by far one of the largest issues which prevents coral from depositing to their skelatons normally.

Cheers
Steve

 

[Clownguy]

The only sps that really grows well is my monti cap and the growth on the other is thin not thick like a lot of the other tanks I see. How do you suggest I pull down my Ca, Alk and Mg?

Chris

 

[kevinpo]

To reduce the calcium and alkalinity levels turn down the bubble count on the reactor. For your brand reactor I would set the bubble count 15-20 bpm.

I run about 3.0 meq/L for alkalinity and 400ppm for calcium. I average about 3/4- 1" a month. I run 400W bulbs driven by HQI ballasts. For 250W bulbs you need to be 24" or less from the bulbs for high light corals to grow fast and have colors you like. Water flow is just as important as lighting. Most high light, branching SPS like very high alternating current. 20X tank volume per hour is a good starting point.
Also consider some corals just don't grow fast no matter what you do. I filled a 450 gal with almost all corals that grow slow (about 25 of them). There are plenty of just Acropora species that grow slow (I'm talking about less than 3" a year).

HTH,
Kevin

 

[chadfarmer]

what is your phosphates?

 

[Clownguy]

Phosphate is 0. I will turn down the buble count to 15 I am at 20 bpm now. Would 12 bpm be to much?

Chris

 

[kevinpo]

Try 10 bpm. Also do you have any leather corals mixed in with your SPS?

Regards,
Kevin

 

[Clownguy]

No softies strictly SPS only with one clam.

Chris

 

[Clownguy]

Well, I rechecked my levels just now and the alk is down to 9.9, but the Ca has only come down to 485. Is it going to take longer for the Ca to come down then the alk?

Thanks,
Chris

 

[steve-s]

Ca is typically depleted much slower than alkalinity (20ppm Ca per 2.8 DKH alk). An easier way of bringing it down would be mix some new SW to the desired target chemistry and do a few water changes once it's mixed/aerated for a day first. Otherwise you will most likely get there by months end given your depletion rate.

Cheers
Steve

 

[Clownguy]

Thanks for the info, checked my levels again today and the alk was the same, but the Ca had dropped to 475. I will try to drop it slowly with a lot of water changes over the next few weeks.

Chris

 

[Clownguy]

Quick update on the levels, Ca is down to 470 and slowly going down but now my alk has dropped to 7.5. I have turned off my Ca reactor for the last four days hoping to bring down the calcium which it did slightly. I have also noticed some more growth on all of the frags i have had since droping the levels, now I want to bring the alk back up slowly while still trying to drop the Ca some more. Should I just use a alk buffer like kents super buffer dKh or what? Any suggestions are helpful. Thanks

Chris

 

[steve-s]

No water changes?

Buffers will work. You can use this calculator to figure out what you need. Keep it under 10 DKH though.
http://home.comcast.net/~jdieck1/chem_calc3.html

Cheers
Steve

 

[kevinpo]

I shoot for around 8-8.2 dKh. When you bring up the alkalinity the calcium will drop a bit more.

Regards,
Kevin

 

[Clownguy]

Well my dKh is now 8.3, but the Ca is still at 470 ppm. One out of two aint bad. I have now set the bubbles at 10 per min and will see how that goes, may have to slow it down even more.

Chris

 

[kevinpo]

Or add more stony corals and clams :lol:

Regards,
Kevin

 

[fishermann]

Chris why not just turn the reactor off until you get your calc down and buffer the alk for now, I know your tank and you are starting over with mostky small frags and probably don't have much need for alot of calc yet.

 

[Clownguy]

Hey john, that is pretty much what I am doing, but I am running it for a few days and shutting it off for four days and will see how that works.

Chris

 

[kevinpo]

Be sure not to let the water stagnate in your reactor and then pump into your tank. If you stop the water flow completly I would flush the volume of water in the reactor into a bucket first before setting the drip again.

Regards,
Kevin