Help: SPS bleaching and STN

[Myka]

Originally Posted by gregzz4

You think 4 x MP10s isn't enough for a 70G tank ?

I'm running 2 x 10s in my 75G and can't run them @ 100% without either blowing flesh off corals/polyps stop growing on one side, or causing them to grow sideways away from the props

I don`t think you`re setting your powerheads up very well then. Certainly you can`t place powerheads so they shoot directly at corals. The MP10s are only 1500 gph full blast which isn`t enough to push across a 48 inch tank. If the MP10s were situated on the back glass pushing towards the front more velocity may be able to be made. SPS though need a lot of water movement throughout the tank and appreciate velocity.

My 90-gallon which is very similar dimensions to a 75-gallon has two Tunze 6105 (3400 gph) and a 6055 (1450 gph) and I can run all of them full blast with the narrow outputs on them and as long as I have the powerheads situated well my corals will keep their flesh on. My tank has about 92x turnover where the OP`s tank has about 80x turnover. Even though these numbers are quite similar, the larger pumps in my tank create higher velocity.

The Tunzes`new wide flow output option is really cool because you can get the same amount of flow with less velocity. LPS do not appreciate velocity. In a mixed reef like the OP`s, creating flow that makes all the corals happy is challenging.

Chizer, I would try moving those MP10s around to create more velocity near the SPS. If you set them up on the back glass pointing towards the front glass you should be able to achieve this. The VorTechs can be a bit awkward though since you can`t control their direction.

It could very well be the tap water though.