Had a mini-revelation on flow for LPS

[kkelly007]

I have a 105g DT that has been up and running for 2 months: Vectra M2 return pump, two Reefwave 45's, Red Sea 600 skimmer, and three ReefLED 90's. I have four LPS frags--i.e., blasto wellsi, meteor shower cyphastrea, dragon soul favia and a hammer--fire shrimp, and a small CUC. Plus two clowns in QT. I've had the corals for two weeks and they all appear to be thriving. Last night I was doing a 15% weekly WC and, although I had mixed the new saltwater (Tropic Marin) that morning, I had not heated it. So I started heating it immediately prior to siphoning out the old water and I underestimated the amount of time that it would take to properly bring the new water up to temp, so I had to wait around 45 minutes with zero flow from anything. I was mesmerized by the dead calm water and how crystal clear it was, especially looking down from the top--looked like the lagoons that I've seen on this web-site.

My mini-revelation: although my hammer has looked very healthy and opening up from Day 1--as well as the other corals--he was FULLY extended with no flow and it was just awesome. My Blasto also looked like he was puffing up a bit more. So I began to think if I don't have any SPS that need higher flow and high placement, is it even possible that my overall tank flow could ever be too low? Or asked another way, would my healthiest solution be to dial in just enough flow to make sure no dead spots, but no more? Has anyone had experience with this? I already have these corals sitting in the lowest flow area in my tank, but I brought my Reefwaves down to 2 (and they were only set on 3 prior to this) and turned my M2 down to 75% (down from 85%). If my math is right, this is about a 20x/hour turnover. I've read a ton of articles on this topic, many on this site, but flow and coral placement is such a difficult titration to get right, and I do not believe I've seen one about simply reducing the flow everywhere to the lowest possible level.

And it seems like the prescribed care for each and every LPS that I read about all say: "[LPS] prefers low flow and low light".

And if anyone has Reefwave 45's in a 100g+/- LPS tank, please let me know what your settings are. Thanks for any thoughts you have!!

 

[andrewey]

I think you figured it out. While I would caution any new reefers reading this that judging flow simply based on maximizing the size of LPS is a poor metric (as many LPS may be largest in no flow as you've found), the availability of high powered wavemakers often means LPS are receiving more flow than less flow. Most LPS are pretty tolerant to a range of flow speeds/patterns, but so long as you are ensuring the health needs of the coral are met (e.g. enough flow for gas exchange, waste removal, etc.), then you can certainly dial in your flow