Gravity Feed?

[alrha]

Now that I have an external skimmer (TC2560), i have the option to gravity feed it off my drain to the sump or to pump feed it with a dedicated pump.

I realize that with a gravity feed i save myself the extra electricity required to power a feed pump and i am constantly skimming "raw water" but is it as reliable as a dedicated pump? would the air bubbles that get sucked down the drain affect performance of the skimmer? do i really want to have all the drained water instantly skimmed? doesn't that prevent any food/pods from making their way into the refugium?

 

[juiceguy]

if you gravity feed your skimmer you will need a valve to control the flow into the skimmer and that could sometimes be a PIA to dial in. you usually cannot process all your "raw" water because your drains usually drain out more than your skimmer can handle. depending on what the skimmer requires, you may have to "t" off your drain to feed the skimmer or if you have dual drains, maybe dedicate 1 drain to the skimmer.
the air that your drain draws is not an issue because of the pinwheel pump is only going to chop it up anyway. i wouldn't worry about pods and such as they always find there way around.

 

[alrha]

well my skimmer can handle 500-800gph. I dont know for sure how much i'm draining but i'd bet its less than that, so the drain will probably be 100% to the skimmer. if i would use a feed pump it would be to make sure it's getting enough flow which i worry the drain may not provide.

i would have it T'd off anyway to be safe and of course a valve should i ever need to dial it in for any reason.

i understand that the extra air will get chopped, is there concern with having perhaps more air in the skimmer than intended? or would it be non-material?

 

[MO~IDOL]

hope this link help scroll down to post #5. I use the same method for my AP600 u need to know the required water throughput in order to get the efficiency.

http://www.reefcentral.com/forums/showthread.php?t=1083183&highlight=Gravity+Feed

 

[alrha]

thanks for those links

 

[MO~IDOL]

np...btw nice toy u got!

 

[Galantra]

When I had my AP702 it was actually gravity feed and it workded very efficent. I actually didn't have to setup a T off my drain.I completly set up one overflow directly to it and wasn't concern with any extra air I felt it worked better gravity feed than with a pump.

 

[TimberTDI]

If I remember Fritz tried gravity fed and I recall he wasn't happy with it.

 

[TimberTDI]

http://www.manhattanreefs.com/forum/general-discussion/18158-100-drain-into-skimmer.html

Please don't tell my wife that I remembered a skimmer thread from three years ago:shhh:

 

[alrha]

ok, i just tested my drain - i drain ~400GPH now but can bump it up to ~600 by decreasing flow to my fuge (T'd off my return pump). i can just have it fully drain to my skimmer then play with the valve on my fuge to adjust flow rate.

 

[alrha]

just read that long thread - i happen to like the idea of 100% drain to skimmer but am worried about the inconsistency of it. Bear in mind i am draining from a living room to a basement fish room in a 2" pipe (will need to reduce to 1" intake).

 

[alrha]

attached is a diagram i made of my plumbing (will T off the drain to the sink and use that to feed the skimmer - as illustrated). The 2" drain reduces at the top T to a 1.5" which I will reduce at the lower T to 1" - if there is any excess flow (i dont think there will be) it can flow across the top T to bypass to the sump (as it does now pre gravity-feed).

Think I will be ok as far as air/surges/etc?

 

[cali_reef]

Be careful draining from a floor up, water may back flow through the air intake hose when the needle pump is off for what ever reason. Test it a few time before you go with this as a permanent solution.

 

[alrha]

didnt think of that - i'll be sure to look into that. thanks.

I got it set up now via an Eheim and will try out the gravity feed once i get the parts i need to plumb it (i am also going to increase the impeller on my Reeflo Marlin to a #6 for more flow). Gonna put some clear PVC as well before so i can visually see how the flow to the skimmer is on the gravity feed.

 

[jrobbins]

I had my old skimmer set up to gravity feed from the tank. I never had an issue with the water coming up the airhose. the way my skimmer was set up (DAS EX1) seems similar to the deltec you have. The only way for the airhose to overflow was if the water level in the whole unit rose above the neck of the skimmer.

What really worried me about doing it was if a siphon started and pushed too much water through the skimmer, but that never happened to me. But you seem to have covered that with the Tee.

 

[alrha]

yes, the upper T has no valve (i just open the valve to the bottom to drain water to the sink for water changes). Should I ever need to, I can always close the valve to bypass the skimmer or if the flow is too much for the skimmer, or if there is a blockage, it can always flow back the old route (to be known as the bypass). What i like most about this is that all flow into my sump (except any bypass if necessary) will be fully skimmed - and the tank will be fed fully skimmed water plus any bonuses from the refugium.

 

[alrha]

finally plumbed in the gravity feed. here are some shots of it.