The difference a pump makes.

[Jscwerve]

So initially I was building a small system with a 60 gallon display and my current sump that has a 37gal max capacity. Plans changed and I ended up with the 125 gallon that I currently use as my display.

I sized all of the components accordingly and upgraded for the larger system. Except for the return pump.

I had read that you can get away with, and it helps to have more reaction time with the skimmer, with a small pump. I figured I was fine. I have been running a Rio 1700 since I filled the tank. I figured I was getting around 350gph (rough estimate) through the sump, That is almost 3x tank volume, so fine right? From everything that I've read, your flow numbers need to be high from the powerheads and use just enough return flow. I'm running about 1800gph from the powerheads (rw-8s oscillating wave mode). Everything moves around, there are no dead spots, but I noticed that food bits would still settle to the bottom eventually.

I'm constantly reading/researching various sources and I noticed a pattern of folks needing to replace their filter socks every other day or so. Strange to me, as mine routinely last a week and I feed a little on the heavy side.

I am currently fighting dinos and progress has been slower than expected. I'm running carbon, GFO, socks, 3 kinds of macro in the sump on an opposite lighting schedule, frequent water changes. Sump algae isn't really growing, and dinos are still a problem.

What could it possibly be is all that runs through my head.

Return pump. I thought MAYBE there isn't enough flow for particulate to be easily falling into the overflow. Fine. I'll change the pump. In comes the Eheim 1262. If you're gonna go big, go big, right?

The filter sock I put on with the new pump on Sunday was almost overflowing this morning. I've never had that happen. I actually didn't know what people were talking about an "overflowing" sock. I'd just change them after a week regardless. Also my skimmer filled up in one day.

Conclusions: More sump flow has increased particulate suspension in my tank and is moving a lot more bad stuff out of the display and into a filter sock. Having only 3x volume through the sump is NOT ENOUGH (for my tank anyways). I think I'm getting around 600gph now and that may be too much, but I can always throttle it back.

Now I can actually see food bits/etc migrate toward the overflow when I turn the pump on after feeding time. Before, all I could see was everything just getting blown back and forth across the tank by the powerheads. Hopefully this will assist with my dino battle.

The more you know.....

 

[thegrun]

On a side note you should change out your filter socks once every three or four days even if they are not dirty as they will start to produce nitrates if you let them go longer. It's hard to beat an Eheim pump for durability, efficiency and running quiet. I suspect eventually I'll switch to a DC pump, but the Eheim hobby pumps last forever.

 

[Fitz19d]

Also, while I think the return was underpowered a bit, I think you could have been benefiting from greater flow from powerheads too. Either one of the 8's being a 15, or really I like multiple moderate pumps to do better stirring than with just 2 pumps on opposite ends.

 

[Jscwerve]

Also, while I think the return was underpowered a bit, I think you could have been benefiting from greater flow from powerheads too. Either one of the 8's being a 15, or really I like multiple moderate pumps to do better stirring than with just 2 pumps on opposite ends.

I would generally think that was the case as well, my soft corals on the other hand would disagree.

I tried more powerhead flow. After a certain point though my torch, goniporas, cloves, etc all look like palm trees in a hurricane. Even when sheltered by rock work. I am going to look into replacing the RWs though, it seems their flow is very directed and not diffused. They are also not reliable in any way shape or form whatsoever.

Even with the powerheads turned up I still could watch food stuffs and whatnot just circulate around the tank and not make it to the overflow.

PS, just did the pump calculations for the old pump. It is saying 271gph is what I had before. Not even 3 times the display volume. Calculated with a pump that's close to the Ehiem (1262 not on the calculator) and am getting about 530 now. That's approx 4.25 times turnover. Correct me if I'm wrong, but I thought 3-5x display volume was recommended for sump flow.

 

[bshow24]

I would generally think that was the case as well, my soft corals on the other hand would disagree.

I tried more powerhead flow. After a certain point though my torch, goniporas, cloves, etc all look like palm trees in a hurricane. Even when sheltered by rock work. I am going to look into replacing the RWs though, it seems their flow is very directed and not diffused. They are also not reliable in any way shape or form whatsoever.

Even with the powerheads turned up I still could watch food stuffs and whatnot just circulate around the tank and not make it to the overflow.

PS, just did the pump calculations for the old pump. It is saying 271gph is what I had before. Not even 3 times the display volume. Calculated with a pump that's close to the Ehiem (1262 not on the calculator) and am getting about 530 now. That's approx 4.25 times turnover. Correct me if I'm wrong, but I thought 3-5x display volume was recommended for sump flow.

You are correct, 3-5 overflow is good and will be the best option for your refugium to do it's job and skimmer as well. But depending on what type of corals you keep, your powerheads are nowhere near where they should be. Soft corals you should be good with, but if you keep any SPS, you need to bump that number anywhere from 30-50x tank volume.

 

[dbigfoot111]

yep

 

[SFish]

I thought 10x turn over for your return pump was the norm and 5x was the lowest. Never read anything about 3x. That seems really low to me. Also I would use the total volume (DT+Sump). Your filtering all your water not just the water from the DT so in my mind I want to turn the whole system over so many times per hour not just part of it.

 

[homer1475]

Everything I've read when researching building my sump, was 3 to 5x the turn over rate. You don't want a high turnover rate as you want to maximize contact time for your skimmer, macroalgae(fuge if you have one), and any media your running.

And yes it should be total system volume, not just the display. But also keep in mind, that an 100G tank is no where near 100G once you add rock and sand. Take for instance my 80 rimless with 30G sump(should be roughly 110G). After displacement and the fact with a rimless tank you leave the tank about an inch low, and the sump is no where near full, I have roughly 70G of water total. 2 30G brute containers for my first large water change just about emptied the sump and tank.

 

[SFish]

Isn't this a debated topic between high flow and low flow? Why not get a DC pump with a higher rating and turn it down?

 

[firefly73]

i ended up buying a vectra m1 $$$ but freaking awesome. ive got around 530l in my system with sponge in the weir cleaned daily poly filter in the sump cleaned every 2 days and my skimmer , gfo, biopellet reactor and display fuge all recirculate

m1 runs at approx 4000 lph so around 8x per hr

before this i had a waveline dc good pump but seemed to suffer from head loss when slowed down so needed to run it faster which did make it rather whiney didnt bother my but wife hates noise. running cost was little high to (compared to the m1)

if your not seeing bits in your tank then they are settling out or you have a sparkling clean tank..........

 

[SFish]

I've been looking at the L1 myself

 

[firefly73]

I've been looking at the L1 myself

well they are $$$ but i cant fault mine. quiet low running cost flexible.

only thing id say is as a closed loop with eductors not very power efficent but soooooo quiet!!

 

[Jscwerve]

A quick update after running for almost a week now.

I've taken the advice earlier in the thread and have upped my powerheads as well. I'm moving a lot more water.

In an amazing fashion, either by coincidence, by all the stuff I've been doing to battle it, or a combination, I'm starting to win the battle with the Dinoflagellates in my tank. Like a light switch they are not reappearing almost at all. Additionally I was having to scrape the glass of my tank every other day it was building up so much film. Now it's been three days and it's clean.

I do thing that the return pump made a big difference. With the wavemakers working as they do I was getting decent flow in the display, yes. Having a weak pump didn't get enough water exchange now though I'm certain. There wasn't enough flow to draw particulate into the overflow so it would settle wherever. Yes the powerheads were moving water, but they move it back and forth more than anything (wave mode). I could change to a constant mode, but then I'd have to pretty much build rockwork around all of my soft corals.

I also thought I was doomed because I had to take my dual reactor (carbon/GFO) off line for a while because of the Eheim pump footprint (reactor was in the sump). As I mentioned, things are going splendidly and I have yet to hook it back up (I will as soon as I get it plumbed).

Honestly with the experience I've had so far with fighting dinos and flow/pumps etc and being all delicate not to create hurricanes, If I ever do another tank it will be bare bottomed.


I'll update again in another week about the dino problem.

 

[SFish]

This is why I wouldn't run less then 5x on the return. I think to high or to low would not be effective. To low and your just running the same water around in the sump over and over again.