Low turn over sump vs. chiller

[mpderksen]

Spring means getting ready for the chiller to kick in. Just tested my return flow and it's 180 GPH.
Equipment specs:
75 gallon DT
40 gallon sump that operates at 9" depth
QuietOne Pro 5000 pump, 1,400 GPH with 0 head
Reef octopus 110int skimmer w/ 92 GPH pump
JBJ 1/10 hp chiller (needs 240-960 GPH flow)
Mp10 on one end, and wp25 at the other for flow
Currently I'm running at 2x the skimmer capacity, through the sump. The flow goes from the return to a tee. Tee goes left to my dual GFO/carbon reactor, and straight up and over to the chiller. Out the chiller to a Y filling that is connected to the 2 returns. Overflow is a full siphon, controlled by a gate valve, with a 3/4" emergency. I think 3/4" PVC can handle 600 GPH is the siphon gets plugged, so that's my upper limit.
I need to get over 250 GPH with this for the chiller, but I'm not sure if my return lines have too much restriction. If I can, should I:
1: make the return lines bigger and less bends to increase flow?
2. Put the chiller on a separate pump?
Should my goal be to maintain low sump turnover and shoot for the minimum the chiller needs? The surface is perfectly skimmed at the current rate. I'll get pictures later.

 

[deave]

I would increase the flow through the sump and have the return plumb through the chiller. I usually keep the flow through the sump around 3-5 times turnover of the tank and let the power heads do the rest. Just my 2 cents. Cheers!

 

[mpderksen]

I would increase the flow through the sump and have the return plumb through the chiller. I usually keep the flow through the sump around 3-5 times turnover of the tank and let the power heads do the rest. Just my 2 cents. Cheers!

Hey neighbor. (I'm in Manteca). That's my first thought too. I am not sure where the restriction is hat would cause such a drop. Surely the chiller itself causes a bunch. But my return lines are 2 X 1/2". So that could be it too. Wish I could calculate each section more accurately.

 

[mpderksen]

So here are the pictures:
First, the pump and 1" hose and tee the the reactor

Next we have the 1" hose going in and out of the chiller

Now the Y barb connector that goes fron the 1" to 2 X 1/2"

Finally my street 90s that go to a threaded bulkhead. The other side is a 1/2" threaded lock line that is just below the surface.

Suggestions? My guess is the 1/2" sections....

 

[wcharon]

Well I am in the same boat as you are. I used to have a Waterblaster pump to feed my Chiller and Manifold and now I bought a RODC 5500 which they told me was better in terms of flow than the Waterblaster.

I mounted it and the flow is way low, at the point that the Chiller (Artica 1/4) now runs 2 hours to cycle the tank down 2 degrees but it only turns on 1 time a day which before was 2 times and in some cases 3 times.

Revising my plumbing to see if something was weird I found that my plumbing is 3/4" and should be restricting the flow so I have work to do this weekend and will be changing my plumbing to 1" all the way and reducing the outputs to 3/4" to see if the flows get better. I wrote Artica and they also recommend me to push the most flow thru the Chiller as suggested by the manufacturer and then fine tune from there as their are variables that affect Chiller operation like ambient temp, lights, etc.

Hope that helps...

 

[mpderksen]

Did they mention how much is lost going through the chiller? I don't want to do it, but I may lug the pump and chiller outside. I can put it all in a tub of fresh water and check it before and after. Pretty easy to use a 5 gallon bottle once I'm not under the stand. It's cleaning time for the pump any way.
If it turns out my loss comes from the barbed 1/2" sections, maybe I move up to 3/4". The trick with be enlarging the holes I drilled in the euro brace on top for he bulkheads. It's acrylic, so not impossible (I did it with the tank running last time. I followed the design from GMAC reef site.

 

[wcharon]

No. They did not mention. What they stated was a lost of around 20% if flow using 3/4" vs 1". I will asume is something similar.

 

[ca1ore]

Losing 85% of flow to head and friction resistance seems like an awful lot though (even with some flow diverted to reactors). I'm unfamiliar with your pump, so perhaps it doesn't handle pressure well ... but 85% loss? I'd be looking for obstructions first (clogged intake, for example). If no that, then upsizing the return piping where possible.

 

[wcharon]

Losing 85% of flow to head and friction resistance seems like an awful lot though (even with some flow diverted to reactors). I'm unfamiliar with your pump, so perhaps it doesn't handle pressure well ... but 85% loss? I'd be looking for obstructions first (clogged intake, for example). If no that, then upsizing the return piping where possible.

Sorry Ca1ore but where did you get the 85% of loss???

 

[ca1ore]

OP stated 180 gph from a pump rated at 1,400 ..... ok, sorry, not 85% it's 87% loss.

 

[mpderksen]

Sorry Ca1ore but where did you get the 85% of loss???

My pump is 1,400+ GPH, but I'm getting 180 to the DT. That's my OP.

 

[wcharon]

Got it. Sorry for the confusion...

 

[deave]

I agree with Ca1Ore, 85% loss is pretty high. Do you have a ball valve going to your reactors and how much are they dialed down? When was the last time you cleaned your pump? It would be a good test to just plumb a hose from the pump to the tank and test the flow. From there you can work backwards. Add in the chiller, then your reactors, etc...

 

[mpderksen]

Low turn over sump vs. chiller

Indeed. That's the plan. I'm going to the store for some fittings, (currently no unions, so it's tough to work on). Then I'll test everything on the patio. I am sure I would flood the living room if I tried this in the sump.
Oh, and there is the standard flow control Valle on the BRS reactor, and it's only open enough to make the GFO tumble lightly. I'll measure that separately

 

[deave]

Nice, let us know how it goes!

 

[mpderksen]

Okay, got a union (will make future maintenance easier), and part to add a gate to the manifold, and threaded fitting in case I want to add an ATS later.
Any thoughts on replacing the poly hose I have between the return pump and the chiller? The chiller has barbs, not MPT.

 

[mpderksen]

Help! I was wrong. I got all the fittings, and the barb fittings on the chiller are actually 3/4", so the poly hose fitted to the 1" PVC is also 3/4". It might have come with 1" ones, but all I have now is the smaller. So, to get the flow up, should I split the 1" line off the chiller and send half through the chiller, and the other half in it's own line to the other return?
I can use gate valves etc., to control how much goes to each side.
The other option is to enlarge the output from the chiller to the tank, but unless I can get bigger fittings, I think it will still bottleneck at the chiller. Thoughts?

 

[mpderksen]

Low turn over sump vs. chiller

Totally spamming my own thread, but I guess that's my choice, right?
I installed the new manifold, with the gate valve for the reactor, cleaned the return pump and added the union. Zero change in flow. (But I do feel better about the expansion fittings if I need to go ATS, and having the gate valve for maintenance).
Next, I need to look post-chiller for restriction. Since re-drilling the bulkheads would be last resort, I will replace all the lines between the chiller and street-90s with 3/4" PVC. Unions too, obviously. If I'm still screwed, then I'll redrill. The only thing NOT really thought out is another gate valve to direct flow back to the sump if the flow end up being TOO much to the DT. In that case, I will tee the reactor line to a fuge return with the gate valve. That won't be difficult, just annoying. But I serious doubt I'm going to end up going from 180 GPH to over 960 (the max for the chiller)

Stay tuned (if you care....). I can't believe anyone can follow my wine-induced ADD at this point....

 

[mpderksen]

Changed out the section from the chiller to the return, but kept the 1/2 street elbows to avoid drilling. I closed my gate valve on the siphon, leaving only the 3/4" emergency open to the sump. It seems near full capacity, but when I time how long it takes to fill a 1 gallon jug in the sump, it takes 12 seconds. (Replicated 3 times). So now I'm confused. The charts I see show 660 GPH for a gravity-fed 3/4" PVC, yet, if my math is right, I'm getting 300 GPH.
So I've made over my chiller's minimum of 240, but I would expect twice that for my emergency drain to handle. What am I doing wrong? I still can't believe my pump would go from 1400+ to only 300.