Cycling power to powerheads?

[Bakerman]

Question. Been researching powerheads and trying to come up with a reasonably affordable way to create random patterns. Looking at some of the "wave" kits which just appear to be simple timers that start and stop the powerheads at timed intervals, they seem overpriced for what they do. But, I'm handy with the wire, and I think I could greatly improve on the random factor with my arduino setup, truly making it random with many, many more combinations of flow creating more and more...well random.

Anyways, I've also seen a number of individuals say that this will only shorten the life of the powerheads to a great extent. I believe there's a great bit of truth to this as starting any piece of machinery usually presents the greatest amount of wear. Especially if they really do use water flow as their bearing support and/or lubrication. But again, looking at the timer based systems, the manufacturers don't seem too concerned about this?

To be clear, I'm not suggesting I PWM the motors or cycle every few seconds. I'm thinking 3+ pumps, relatively slow cycles of, say, 15 minute intervals or the like, and lots and lots of different combinations/runtimes/etc. If you think about the runtimes on the pumps, different pump combinations, etc, you really do have tons of options. Nearly endless.

Thoughts? I'm also open to testimony for favorite powerheads in this configuration.

Thanks!

 

[AZDesertRat]

Most powerheads are not designed for frequent starts and stops. This is why the newer Jebao, Sicce and Hydro powerheads are so popular, they can standup to the starting and stopping.

 

[Bakerman]

I was kinda leaning toward 3 Hydor Koralia Nano 425gph's in a 75gal reef (mostly fish & softies). Think these would live a good life? What bout the type/size/# of these Hydor's in that tank? I also plan to have roughly 400 gph flow through the 75gal display tank and the 55gal sump/refugium/skimmer.

 

[AZDesertRat]

Way too small. I run two Nano 425's in a 16G nano reef and they are pretty lame in a tank that is only 24" wide. They barely move the leathers and anemone at all.
My 100G mixed reef with a 30G sump has a Water Blaster HY-5000 return pump and had two Hydor Evolutions 1400's, I was very happy with them but changed to two Jebao WP-25's and am much happier. The Jebaos didn't cost much if any more than the Evolutions, are DC powered and have a built in controller for much more versatility. A couple WP-10's or their new RW series might be better choices for a 75G.

 

[rockskimmerflow]

I've used ac (non-controllable) tunze powerheads on 15 to 20 minute cycles continuously for over 3 years straight. With cleanings every 6 months I have yet to see signs of significant wear on the pumps at 3 years in. They are still going strong. However, I have in the past seen Hydor pumps die after 6 months to a year of frequent (1-5 mins) on off cycling.

I concur that 3 hydor 425s will be wayyyy underpowered for a 75. Not sure what's up with the rating on that pump, but having seen it in action next to similarly rated tunze and sicce nano pumps it pales in comparison. It is great if you just want very gentle flow like for a seahorse or similar biotope setup.

My only other piece of advice is to rethink pursuing the ultimate in random flow. Tanks that I've run with dc pumps and frequent flow variations have honestly grown coral at a reduced rate to tanks that I've set up with a 1 to 2 hour flow cycle. Corals that get flow in 1 direction for at least an hour then receive flow in different direction for another significant interval seem to respond exceptionally well compared to those being battered with random currents throughout the day. I don't know the exact mechanism as to why this is but it seems that perhaps this long cycle flow setup would be more akin to the directional currents on natural reefs. Just my thoughts after having chased the random type flow setup only to find it didn't improve things compared to simpler systems.

Good Luck with setting up your flow system! It's always fun playing with new tank ideas.