Sps health under 20K mh

[Eric]

Have a question that's bothering me for sometime........my sps corals are not growing under my 20K MH but are colouring up steadily from brown frags to blue,green,yellow and purple............polpys are extending.........is it healthy? Is it getting enough light from the 20k mh?

Eric

[FuEl]

Depends on the wattage of your bulb. If you have a 250W or 400W bulb instead of a 150W you will get better growth as the PAR is higher.

Generally bulbs with lower kelvin ratings have higher PAR and are more conducive to growth. If you want them to grow faster you can consider changing to a 10,000K bulb but be sure to acclimatize your corals slowly if not they might bleach.

[Eric]

Depends on the wattage of your bulb. If you have a 250W or 400W bulb instead of a 150W you will get better growth as the PAR is higher.

Generally bulbs with lower kelvin ratings have higher PAR and are more conducive to growth. If you want them to grow faster you can consider changing to a 10,000K bulb but be sure to acclimatize your corals slowly if not they might bleach.

I using 2 x 250W 20K MH for my 3ft tank............already 2 mths........almost no growth on the frags at all although I'm very happy with the colouration.............Collecting a 10K BLV from marinereef later on...........will try and see how it goes..........thx for the tip fuel..........btw, I can't shift the height of my MH, neither can I shift the frags cos all glued to a piece of LR and the tank is already fully packed........how can I acclimatize my sps? I have a normal type of glass, but the last time I use it, the glass crack due to the MH heat.......any other cheap method for acclimatizing?

Eric

[Achilles Tang]

I use a combi of 20k and 6500k. I still get good growth rates from frags right on the sandbed under the 20k lamps.... maybe its because mine are 400w!

Fuel is right... PAR values have to be taken into account when choosing a lamp and these will increase with lower K bulbs or higher wattage lamps.

AT

[strat]

I using 2 x 250W 20K MH for my 3ft tank............already 2 mths........almost no growth on the frags at all although I'm very happy with the colouration.............Collecting a 10K BLV from marinereef later on...........will try and see how it goes..........thx for the tip fuel..........btw, I can't shift the height of my MH, neither can I shift the frags cos all glued to a piece of LR and the tank is already fully packed........how can I acclimatize my sps? I have a normal type of glass, but the last time I use it, the glass crack due to the MH heat.......any other cheap method for acclimatizing?

Eric

Hi Eric,

Changing back to 10k again?

So do you on 2 250W MH together?

Or alternate between days?

[FuEl]

Since you're using 2X250W I doubt the problem could be with your lights.

If your calcium and kh levels are normal...have you tested for phosphates yet? Phosphates will inhibit calcification of hard corals too.

[Eric]

Hi Eric,

Changing back to 10k again?

So do you on 2 250W MH together?

Or alternate between days?

250W 20K - 1300-2200hrs

250W 20K - 1400-2330hrs

Overlap of 8hrs

Eric

[Eric]

Since you're using 2X250W I doubt the problem could be with your lights.

If your calcium and kh levels are normal...have you tested for phosphates yet? Phosphates will inhibit calcification of hard corals too.

Fuel....you are right..........it could be the phosphate......mine is not zero.......<0.1ppm & my KH has drop to 6.........damn wats the best way to boost up on the KH?

Looks like I got to invest on the Rowaphos........btw do you guys use RO or DI water? I suspect my phosphate is coming from my tapwater everytime I dose the calcium and kalkwasser.

Eric

[FuEl]

Try to maintain kH levels at 8 and above. It could be your low kH too that might cause the slow growth of your corals. You can maintain it using Seachem's reef builder or any other kH supplement but if you are going heavy on sps this dosage regime will tire you out sooner or later. Not to mention the money spent on supplements. You'll save in the long run by investing in a Ca reactor in the first place. Although the initial investment is high but it will be cheaper to run in the long term.

For the rowaphos it is best to use it in a fluidized mode. Makes a great deal of a difference compared to putting it into a bag. You running carbon? Running carbon will help too by keeping your dissolved organic levels low.

[Eric]

Try to maintain kH levels at 8 and above. It could be your low kH too that might cause the slow growth of your corals. You can maintain it using Seachem's reef builder or any other kH supplement but if you are going heavy on sps this dosage regime will tire you out sooner or later. Not to mention the money spent on supplements. You'll save in the long run by investing in a Ca reactor in the first place. Although the initial investment is high but it will be cheaper to run in the long term.

For the rowaphos it is best to use it in a fluidized mode. Makes a great deal of a difference compared to putting it into a bag. You running carbon? Running carbon will help too by keeping your dissolved organic levels low.

Ya, running on carbon and biophos 24/7 on a DIY FR now.........the CR also can control the KH level ar? How does it control?

Eric