Thank you for your in-depth and comprehensive reply, it is greatly appreciated.
You have stated that the system will be 300 plus gallons which is also what I have been working on...but is that correct?
Since writing the post, I have sat thinking (perhaps over-thinking) about the water capacity of the system. Would I not need to take into account the sand, rocks, and media within the tank, sump, and external cannister and deduct the volume of those from the volume of water (on the basis of Archimedes' principle)?
To my reckoning, that would reduce the actual volume markedly. Also, the dimensions of the tank I gave are the external dimensions but should I not use the internal dimensions? Given the glass thickness is 1/2", and the tank will not be filled to the brim (approximately, 4" below the brim) and there will be a sand depth of 2", the actual dimensions of the tank will be 95" x 26" x 25 1/2" (not including the depth of sand).
I have roughly calculated the total water capacity of the system, without deducting sand, rock, filter media, and sump equipment to be 1245 liters or 274 Imp. gallons, 329 US gallons. Taking into account and deducting the volume of the above mentioned material (2" sand bed, 1+ lbs rock per US gallon, other media) , I estimate the water capacity of the system to roughly be 934 liters or 205 Imp. gallons, 246 US gallons.
Given the above, and being kind to the light units, if the power output when new is 120W each and the tank holds 246 US gallons, then the Wattage/gallons ratio will be a just under 1.5, so, a little better maybe.
Regarding the depth of light penetration, as stated above, I had worked on the assumption of a 30" depth of water, however, taking into account the thickness of glass, the 2" sand bed, and the 4" level of water from the brim, the actual depth of water the lights need to penetrate is 23 1/2". There is a YouTube video uploaded by a Russian guy who checked out the PAR readings using a Quantum Sensor in his tank which had a shallow sand base and a water depth of around 14" to 15". Under a very blue colour setting, he got readings of between 250 and 260 when reading from the base sand level. Under what I would consider a white colour setting, he got readings of between 370 and 380.
I have no idea how this rating compares to what I may expect to get in my tank with my depth, maybe you could throw some light on this? (pun intended).
Thanks for the pointer to the video to
sammy_hehe1245.
I would be quite happy to set the lighting to achieve the best outcome for the life in the tank, though, I do like the blue colour look, and will be happy to add lighting or even replace in time. My intention is to start with a FOWLER setup and add simple, hardy corals in time as my experience grows. Only after that, would I think of the addition of more demanding/delicate coral types. It really depends on what I can obtain in my area. Seems daft that, given my location, there are only two LFS catering for the saltwater hobby and they are on the mainland which is two to three hours drive away plus a 15 minute ferry ride.
Once set, I don't envisage altering the lighting so I have little interest in gadgets that complicate the experience and most days I am at home to monitor the system, when not, there will always be someone on hand, once trained, to caretake the tank as with my freshwater tanks, so, off-site management is not required.
The warranty given on the product I am considering is for one year. However, I have learned from ten years experience of living on Samal that warranties given in the Philippines are not worth the paper they are written on. So, sadly, that aspect of the product, I disregard.
The budget I have set for the initial lighting was determined by the overall budget for the total setup. I didn't realise how much money would be involved until I sat down and worked out the costs! Long-term, and after the tank is up and running to my satisfaction, I would consider additions and upgrades to the lighting and the addition of other equipment to improve the system but for now, 'cheap and cheerful' lights that get me started is the path I will take.
Once again, I am grateful and really value the time you have given to reviewing this light unit and the advice given. Any additional advice and comments you can give to any/all aspects of my reply would be greatly appreciated...I take criticism well so please let me know if I am wrong in my views. I am a complete novice when it comes to the saltwater hobby, though, I have kept tropical freshwater fish for thirty-six years; and, as a hint to my age, I didn't start in the hobby till I was thirty-six years old.
Take care.
