Closed loops in the sump

burningmime

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Different things in the sump mandate different flow rates. For example, UVs require low flow (eg 100-200 GPH) for ich and high flow (eg 700-800 GPH) for bacteria/algae. My new Pax Bellum says it wants 200-400 GPH. Biomedia works well at high flow rates, but too high and it breaks apart. Now toss in a couple reactors for biopellets/carbon/GFO/etc and suddenly you need about 5 different flow rates through various components. The easy solution is closed loops in your sump. However, since the goal is to process X GPH of display water, suddenly it becomes a lot trickier to figure out how much of the display is passing through each component.

The BRS video on UVs said it's a mistake to use a closed loop in your sump and suggested attaching it to your display (which may be difficult or undesirable depending on plumbing and room layout) or return pump (which gets you 1 fairly medium-high flow rate, or possibly 2 if you're running dual return pumps at different speeds -- can you even do that?). So...

1. Should closed loops in the sump be avoided?
2. Is there a way to calculate the effective display tank turnover when using a closed loop in the sump?
3. Can you have 2 return pumps with different speeds?
4. Why are apex flow monitors so incredibly overpriced and require a special extra box instead of plugging directly into the unit?
 
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laverda

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I like to feed my skimmer and extra reactors of my drain lines from the tank to the sump. Don’t waste your money on an Apex flow meter. Flow rates can be roughly calculated based on height, tubing diameter and if it is a full syphon or not. You can also get inexpensive flow meter to hook up to the out put. Another way is to measure how long to fill a 5 gallon bucket. If it takes 10 minuets the the flow rate is 60min/10min*5gallons to get 30 GPH. 60/10*5=30GPH. Another variation is to measure how long it take to fill a plastic bag of known capacity and do the same calculations. TOM makes a flow meter for $50 that should work well for your needs. Only issue is I believe it uses metal parts so use it to adjust your flow then remove and flush with fresh water so it is usable next time you need it. Their are others available with a plastic float as well.
 

QueryLifeDecisions

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Different things in the sump mandate different flow rates. For example, UVs require low flow (eg 100-200 GPH) for ich and high flow (eg 700-800 GPH) for bacteria/algae. My new Pax Bellum says it wants 200-400 GPH. Biomedia works well at high flow rates, but too high and it breaks apart. Now toss in a couple reactors for biopellets/carbon/GFO/etc and suddenly you need about 5 different flow rates through various components. The easy solution is closed loops in your sump. However, since the goal is to process X GPH of display water, suddenly it becomes a lot trickier to figure out how much of the display is passing through each component.

The BRS video on UVs said it's a mistake to use a closed loop in your sump and suggested attaching it to your display (which may be difficult or undesirable depending on plumbing and room layout) or return pump (which gets you 1 fairly medium-high flow rate, or possibly 2 if you're running dual return pumps at different speeds -- can you even do that?). So...

1. Should closed loops in the sump be avoided?
2. Is there a way to calculate the effective display tank turnover when using a closed loop in the sump?
3. Can you have 2 return pumps with different speeds?
4. Why are apex flow monitors so incredibly overpriced and require a special extra box instead of plugging directly into the unit?

If you are feeding water to your accessories from the same sump compartment as where their effluent discharges into, you will get a degree of water recycling. That is, water that has just been "treated" by your UV steriliser, algae reactor etc will be fed right back into it. Theoretically, one could argue this impacts efficiency because you are retreating water that has already undergone treatment. The degree to which this is actually a problem likely depends on the piece of equipment, as well as the tank turnover rate in comparison to the feed rate of your accessories. UV sterilisers appear to be particularly sensitive to this issue, but if you ended up feeding 30% of an algae reactor's flow with "recycled" reactor effluent, I doubt this would be a huge issue (it's not like water exiting an algae reactor has zero nitrate/phsophate, so it'll still suck more out of recycled water). Look at the design of the Nyos Torq reactors - the reactor effluent flows right over the reactor pump suction, and they don't think it is a problem!

My personal opinion on this is...

1. The efficiency of filtration equipment is maximised when the water being fed to it is as "dirty" as possible, so avoiding closed loops/recycling as much as possible is in the best interests of your tank. If your tank turnover rate is high enough (i.e. higher than the total feed rate of your accessories), you can do this by the pump that feeds your accessories in a sump section upstream of the return section (e.g. the skimmer section), and then let your accessories dischage into the return section. This means that "old" and "new" water doesn't mix.
2. laverda appears to have answered this as much as I can.
3. Depends how you have your return pumps setup. If they are feeding a single pipe that returns to the tank, you'd want to get a flowmeter on there to make sure whatever piece of equipment you're feeding it with isn't being starved of flow. If they feed seperate lines, you'd want to make sure you aren't impacting the flow in the tank.
4. I feel like the Apex have been allowed to get away with ridiculous price points and suboptimal design choices for lack of competition. GHL is another brand you should look into, though their equipment variety is not as wide.
 

mtraylor

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To keep it simple. I just run a manafold from my return pjmp and each manifold has a control valve. You can give each are its own flow rate.
 

ScottR

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To keep it simple. I just run a manafold from my return pjmp and each manifold has a control valve. You can give each are its own flow rate.
+1 same.
 
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burningmime

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To keep it simple. I just run a manafold from my return pjmp and each manifold has a control valve. You can give each are its own flow rate.

That seems like the best solution; although probably also the priciest. But isn't the manifold ultimately just recirculating the same water? Like, the percentage of water that goes into the manifold is dumped back into the sump (at least whatever goes through the reactors)
 
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ca1ore

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I need every GPH I can get from my main return pump, so I use a second pump on a ‘closed loop’ in the sump to feed various canisters and filters. I’ve never worried about running recycled water through them frankly. Return pump moves 1,600 plus so not really an issue.
 

Karliefish

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I need every GPH I can get from my main return pump, so I use a second pump on a ‘closed loop’ in the sump to feed various canisters and filters. I’ve never worried about running recycled water through them frankly. Return pump moves 1,600 plus so not really an issue.
What brand/model pump are you using?
 

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