Coral Growth

[bluedeuce02]

Hi, I have a 100g tank, and I cannot get my corals to grow. They are all soft corals, mushrooms, zoos, cloves, and kenya tree. All my readings seem normal, calcium 425, phosphates .1, ph 8.3, salinity 1.26. I have approx 275w of light with metal hylaid and floresents. I don't have a sump, I have a large canister and an external skilter. I taregt feed them 1 week with Reef Roids, and phyto plankton. Please HELP!!

 

[BL1]

Welcome to the site!
What tests are you using, I haven't seen a phosphate test that reads to .1 ... can you list the rest of your tests, Ammonia, nitrite, nitrate, etc. Also, where do you have the corals placed in your tank, and what type of flow are they getting?

 

[bluedeuce02]

Sorry, my phosphate reading is 0.25. I have the corals placed from middle to the bottom of the tank. I have 3 tunze power heads in the tank to create flow.

 

[Bifferwine]

You are missing some of the most important parameters -- ammonia, nitrites and nitrates. What are those reading?

 

[bluedeuce02]

Nitrate is 0, alkalinity is 2.5, nitrate is 10, ammonia is 0.0.

 

[d2mini]

If that's 2.5dkh your alkalinity is wayyyyy too low. If it's meq/l, you are still low.
You want to be in the gray area in this chart.
OZ REEF - Alkalinity Conversion

 

[bluedeuce02]

What is going to be the best way to increase the alkalinity without throwing my ph to high?

 

[d2mini]

Sodium Bicarbonate will slightly lower ph.
½ Gallon Bulk Sodium Bicarbonate for Aquariums - English

Sodium Carnonate (soda ash) will slightly raise ph.

 

[yote]

Just use this Reef Chemistry Calculator and some baking soda to bring you alkalinity up some.

 

[Ulta]

Corals grow slower under low light conditions(Which you are on the low end for a 100g), which makes since b/c they mostly grow through photosynthesis, although I'm sure you target feeding them helps some.

What kind of time frame are these corals not growing in?

 

[bluedeuce02]

They have not grown at all. I have had them for approx 3 months. If anything they have gotten smaller.

 

[Bifferwine]

Also, none of your corals need to be target fed -- or can even eat that food. The food you are adding is not helping your water quality, so I would stop adding Reef Roids and phyto.

 

[Rcpilot]

Water changes once a week always gave me the best growth. All the trace elements and nutrients are in the water. For a 100g tank, I'd be changing 10 - 15g a week.

You don't need a whole lot of light to get good colors out of the corals you listed. But you're kinda low on watts for a 100g tank. If you want to see growth you'll need the right SPECTRUM of light and the right PAR values. You indicated 275w of light - between MH and fluorescent. What are the bulb colors? How big is the MH light bulb? Are we talking compact fluorescent or T5 High Output or standard output? Give us the rundown on bulbs and color.

It could be as simple as adding some T5 HO lights in the 10k range.

Need more info. :mrgreen:

 

[bluedeuce02]

The MH bulb is 250w with 20k spectrum. The floresents are are just standard output, with a 10k spectrum to even out the blue. I do change approx 10g of water weekly.

 

[Rcpilot]

You just need more light.

I'd look for a T5 HO kit and dump another 100 watts of light on there.

The 20k MH you have is really blue. It's very close in color to a 450nnm or 460nm. Corals need a broad spectrum to grow and maintain color. Get some T5 lights and use at least (2) in the 10k range and maybe a couple 11k or 12k to even things out and still give a nice visual appearance.

 

[bluedeuce02]

The demensions of my tank are 36 in long, 28 in high, and 24 in wide. I was told this would me more than enough light?

 

[Bifferwine]

That's actually a 140 gallon tank. And that's on the low end of light even for a 100. It is good enough for softies and most LPS corals, but you could definitely do with more if you wanted to upgrade down the road.

 

[melisssaparker46]

There are really numbers? I didn't know that.

 

[Chris_150G]

I could be wrong but I think that it is a 100 gallon tank. A ran it thru a tank calculator to be sure and got 104 gallons.

I would think that a 250W MH should be ok for soft coral as long as they are within a foot horizontally of the bulb. Three months isn't terribly long in growth time but I would've expected some growth. You do have a Alk problem, maybe that contributed to it.

 

[Dakwan]

those dimensions do work out to 105 gallons but that is a wierd tank size... only 3 feet long but 28 inches tall?

I would say you would need more lighting that normal for a 100 gallon just to penetrate the depth