judging flow

[Jay03GT]

Looking for some help here gang. How do you judge if a SPS is getting the right flow, too much flow, too little flow?

Here is my problem. I've lost a few frags, usually within a few weeks. If I can figure it out in time, they do well. System has been up for 1.5 years. I know someone will ask, so Alk runs 8-9 dKH and stable, Ca ~425 (I drip 2 gal of kalk, 1 gal in the morning, and 1 at night after the lights go out, takes about 2-3 hours to drip), 1.026 salinity with a calibrated refractometer, mag runs ~1300, nitrates around 5ppm. I don't test for phosphate, I don't have a hanna meter. But I've been running phosban in a reactor for 15 months or so, and change it out every 3 months, and there is virtually no algae in the tank other than a couple of valonia and my cheato in the 'fuge grows super slow.

I'm pretty sure the problem is flow related, I think in my inexperience I've been overdoing it. I have a 6105 Tunze and a 6101 Tunze, and about 800gph from my return pump. I also had 2 modded 6025 Tunzes that I took off-line a few weeks ago. The 6101 I'm running the 15v chip and about 1/2 throttle, and the 6105 was running about 1/2 throttle on the 24v chip.

So how are you judging the flow, by watching the polyps? Looking for PE? My problem usually starts with some STN around the base or the tips, and proceeds from there. Any tips to help me out?

[myaerica]

Wondering also is there such thing as 2 much flow?

[sgwill122]

Usually too much flow is pretty easy to tell after the fact that is. Area receiving brunt of the flow is blown off but sheltered portions are fine. I would think too much flow would be seen at the tips as usually the base is down near the rock work where flow should be less.