It is bulb replacement time and I was thinking about trying a 20K. I currently have a Crocea about 9 inches below the light and a squamosa about 16 inches below the light. The light is an Aqualight Pro W a 14K Phoenix and 2 x 65 W actinics. For something different I was going to go with a 20K and swap the actinic pc bulbs with 50/50 bulbs. Thoughts?
Anyone with Clams under a 20K?
- Thread starter jasper24
- Start date
Stoney Mahony
New member
I have a Maxima, Crocea, and Gigas under a 150w 20k pendant and they are doing awsome. Here is a pic from above of the Maxima and Gigas.
WorldNation
New member
mine are also under 20k's, doing great
dj synystr
New member
i have a 125 with a 400 and a 175 one on each end both 20k. my clams open more now than they ever did when i had a 175 10k and a 400 20k. plus the coloration AWSOME with that light spectrum!!
Stoney Mahony
New member
That tank is a hex, not the 55. It's a 150w HQI pendant with 20k bulb and the tank is like 35g(still only around 4.2 wpg and their at the bottom of the tank). I have had the clams in their for over a year and they have grown a couple inches since I got them. I have never seen any problems with them. I also have two croceas up higher in the rockwork.
critterkeeper
New member
"my clams open more now than they ever did when i had a 175 10k"
That's because they're trying to extend their mantle to get more light!!!
Coloration may be awesome - but you may also be starving them...
That's because they're trying to extend their mantle to get more light!!!
Coloration may be awesome - but you may also be starving them...
critterkeeper
New member
Hmmm - guess I didn't read all those numbers right... I was thinking 175w 20k vs 175w 10k
Still, I have no clue why a clam would extend its mantle MORE under the 20K unless it was trying to get more light. I'm all ears if you've got a better explanation than that it's getting less of what it wants from the 20k??? I've never seen or heard of a clam opening up more under a brighter light - it's usually the opposite.
Still, I have no clue why a clam would extend its mantle MORE under the 20K unless it was trying to get more light. I'm all ears if you've got a better explanation than that it's getting less of what it wants from the 20k??? I've never seen or heard of a clam opening up more under a brighter light - it's usually the opposite.
Snprhed
New member
Fair enough MB, but that argument could be made the otherway also, it could be just as usable, or preferred. The argument would be that it comes from Lower K, but we have no idea what the capabilities are. Its obvious that its usable in a way that they can grow at a good pace.
LBCBJ
New member
A 400w bulb's PAR is not even comparable to a 175, not matter what the kelvin. The PAR rating between different bulbs, i.e. a 10k vs. 20k, is not even that much of a difference. I have kept clams under 20k's just fine, although they'll get better growth under a 10k. In the end your clams don't really care what K you have, just along as they are getting enough light. IMO 4 wpg is not enough light to keep clams.
critterkeeper
New member
"The PAR rating between different bulbs, i.e. a 10k vs. 20k, is not even that much of a difference"
This site shows the PAR difference in a lot of bulbs:
http://metricksystem.com/chris/250wcolour/
An example:
XM250w 10000K PAR= 612
XM250w 20000K PAR= 247 (with same ballast, etc.)
The 20K puts out 40% of the PAR that the 10K does.
In addition, the 20K used 285w of electricity and the 10K used only 268w
Here's another site to look at too:
http://www.reeflightinginfo.arvixe.com/select2lamp.php
Example:
Ushio 175w 10000K PPFD= 63
Ushio 175w 20000K PPFD= 35
etc...
This site shows the PAR difference in a lot of bulbs:
http://metricksystem.com/chris/250wcolour/
An example:
XM250w 10000K PAR= 612
XM250w 20000K PAR= 247 (with same ballast, etc.)
The 20K puts out 40% of the PAR that the 10K does.
In addition, the 20K used 285w of electricity and the 10K used only 268w
Here's another site to look at too:
http://www.reeflightinginfo.arvixe.com/select2lamp.php
Example:
Ushio 175w 10000K PPFD= 63
Ushio 175w 20000K PPFD= 35
etc...
LBCBJ
New member
Ok, why dont you pick the bulbs with the worst PAR drop-offs and use them as an example. I was being general and using 150w HQI's as a reference. The differnce in a 14k and 20k is usually only about 5-10. Don't use a radical example for a general statement. It also depends on whose data you refer to.
