ballasts

broz what's the diff between inbuilt and external ballasts? which one more expensive in terms of long term cost?

yo bro.. for eg: i bought a new 650w aqualight MH fixture from the aqualight dealer.. is using external ballast.. thus the weight of the mh fixture will be lesser ... so much lesser.

however, external ballasts require protective casing.. thus extra material. .. higher cost. however the ballasts itself... still the same..

Bro Piglet provided good explanation on the external ballast .. so for internal, no need to provide example other than saying that the ballast is hidden ..

hmmz ok...anyways i'll try to be more specific in my questioning. basically this bro pm me he has 2 2ft lights to sell, one rainbow t5 and the other is the t5 ho from am. the rainbow t5 is NO but has 2 actinic and 2 white. the am one has 2 white 1 actinic. my main concern is that i have a OHF so the space for lighting abit narrow. so what he tells me is that the am though only 3 tubes is brighter but the rainbow is bluer,no issue. he also tells me that internal ballast of the am set makes it thicker than the rainbow one which is external. he also stated that the am set would have higher maintenance cost but i'm sure whether it's because it's an internal ballast or because it's HO. any broz can advise? i have a 2ft x 1ft x 1.5ft nisso

also, the rainbow set is 4x14W but the am set is 3x20W. advice pls

AM = AquaMarin?

If yes, then it houses 3x24W T5 HO tubes (2 white 13K & 1 Actinic Blue 20K) with internal ballast. Brand new 2ft set is only $119 while stock lasts n understand 2 sets left.

Current batch of T5 from Aqua Marin is having "on" problems and replacement batch for them is expecting to arrive early Feb where it can be exchanged with proof of purchase from them.

My advice is get the T5 HO instead of the T5 NO.

yeah correct, it's aquaM. was also thinking about going straight for the HO ones, coz i know myself...sure cannot resist corals. but like i said lah, the higher maintenance is the tubes right not the fact that its internal ballast? or perhaps internal ballasts harder to replace/repair? plus i called the owner during the week, she say new stock coming in next week with the new ballast. then there's the final question...don't know whether will be to wide or not...still have OHF leh.

Fyi, the depth of the 3ft one is about 8.5" or 22 cm and would expect it to be less than 22cm for the 2ft.

Verify with AquaMarin for the dimension.