Sump Question-Rubble Rock

See?? I told you I was a genius.LOL JK;D8)
The only danger IME in running too much flow is maybe getting some micro bubbles in the DT.I have two sets of baffles in my sump so this is a non issue for me.

 

People get confused about this because they think of a fuge as one box that does 100 things. It's isn't. Flows depend on what you are trying accomplish.

A fuge is for growing pods. Period. Refuge from predation. Pods don't need rubble for habitat. They like algae. High flow through a fuge is not beneficial for pods holding on for dear life.

Macro algae is for nutrient export. Some like high flows, some like low flows. Turf scrubbers grow algae that like high flow because turf scrubbers have high flow and that is what grows. That does not mean that all algeas should have high flow.

It just so happens that a fuge is a good place to keep macro algae to keep it out of the way and out of the DT. Pods like the habitat. I don't think it really matters about high flow or low flow as plenty do both. I think very high may be good for some macros, but not for pods. Cheato seems to grow well in any so why not give the pods a break and give them a nice peacefull place to dwell... and allow them to concentrate without being swept away.

Now the fuge is taken care of, the only thing left in the sump is a skimmer. A skimmer only processes so much water... passing 1000 gph by it when it only does 200 gph is a waste of power. Passing 100 gph by it turns it basically into a recirc skimmer.

So who cares about fast or slow flows??? Well the only one that really cares is the one that pays the utility bill. Pumping water from the sump 24/7/365 for absolutely no benefit is a waste of power... but the real problem is the addition of heat. It is a heater... and if you have a chiller you are cooling water you are unecessarily heating. So only move the water through the sump/fuge that needs to be moved for the purpose it is there for... to get skimmed and supply food for pods and macro algae.

Which takes me back to purpose.... rubble has absolutely no purpose in a sump other that to become a detritus trap and become one more thing that needs to be cleaned and maintained. LR needs to provide habitat and filtration for the DT in the DT... if you have a minimalist setup with very little LR in the DT, then a additionl tub of LR in the system will be much much better than a minor amount of trash sitting in the sump. My .02

 

But you are recircing back to the sump that gives no benefit. So the additional flow is not that much. Now it is certainly possible that your flow was too low before... but without data and knowing what the flows were before and now, you can't just say High = better. In your case maybe "more" = better, but it may actually be low compared to others.

It could actually be that your skimmer was not processing to it's cpacity... so now it is and the benefit came from better skimmer preformance, not higher flow through the sump for the sake of higher flow. Just a guess, I don't actually know.

Put a valve on the discharge of the pump and turn down the flow instead of recircing. Recircing takes power and adds heat, throttling does not and has absolutely no effect on the pump.

 

Thank you for clarifying the sump process, Powerman, you're a lot better at it than I am.

There's another part of my thought process that I left out. My reef system consists of a 125 DT and a 30 breeder frag tank. From there the water goes into the basement into a 20 where the skimmer sits, then flows into another 20 with chaeto, then into a 40 breeder that so far is just an extra tank, then into a 100 gallon Rubbermaid with that houses the return pump, ATO, heaters, media reactor. What has had me concerned, is the amount of detritus that accumulates along the way. When I had the sump under the tank, I never noticed it, but with all of the settling area that I have now, I'm surprised how much there is.

My intent with higher flow is to get more of this detritus out of the DT and into the sump where it can be dealt with. My next step will be to increase the slot size on the overflows so that the new return pump can run full open. Then, I'll add a filter sock before the skimmer to catch more of the crap before it ever gets into the sump. I change the socks on my fish system every three days anyway, so for me it's not a big deal.

My fish system had similar issues. Getting the detritus out of the tank also solved those. I went from a Mag 24 to a Dart, and increased the plumbing size from 1" to 1-1/2", which greatly increased flow. When the 125 was upgraded to the 300, I went bare bottom to also help get the detritus out of the DT. That sump system flows into a 90 with a filter sock, then into a 100 gallon Rubbermaid with another filter sock. No skimmer (maybe I'll add one later, maybe not). The result was very little detritus build-up, very clean water and very clean tanks (for big fish).

 

That is a very power hungry way to do it.

So we want good flow in the display tank to keep detritus suspended so it can be filtered out. Filtering it out before it breaks down reduces the load on the biological filters... LR, and algae, or bio pellets. The only thing you have to do that is filter socks and your skimmer.

With your water going down to the basement you are already using much much more power to move it against gravity... all that power is a direct heat input into your water. External pumps are still water cooled. Now that would be OK if you lost a lot of heat in your basement and needed heaters... then the pump heat would be needed and "free".... but you could also insulate your sump.

And yes with all your settling time you do see it settle before it is filtered... so adding flow from a return pump does not solve the problem. You want flow in your DT to get it moved to the sump, then you just need to have it filtered. Velocity is what keeps it suspended... so when it gets to a wide open area velocity decreases and solids fall out. If you increase flow through your sump, you will send it back to the DT, and back to the sump, and it gets filtered out and you see less accumulate... but it would be easier to just remove the settling area, recirc your skimmer so to speak to make sure it cleans what is there, and send nice clean water back to the DT. Fast flowing water past the skimmer does not get it removed. Does that make sense? Same result, much less power and heat, much less flow, less evaporation (maybe).

 

Oh, yeah, makes perfect sense.

Heat, for my system, is not an issue. I live very close to Lake Michigan, my basement is always cool. Most of the sump area is covered with rigid insulation, but mainly for water evaporation. I have the sump in the basement for my convenience, and for more area and options to work with. For that, I'm willing to pay for the extra pumping power.

The DT has four Koralia 1050's, and a K2. It's already pushing the limit to what the LPS can take. (I want to get a Tunze 6028 wavebox when it comes out, though). Anyway, flow in the tank is very good for the corals I keep, plus the additional flow from the return.

My bioload is not very high. Four small fish and corals. Before the pump upgrade, the skimmer output surpassed the return flow, and there was still a lot of settling. With the bigger pump, I should get even more. That's a good thing. The last two tanks in the sump are relatively calm. A lot of detritus settles there. Not much returns to the DT as it is. In an under-the-tank sump, I could see it going right back into the DT.

More flow from the return pump did solve the problem of getting more suspended crap out of the DT. The difference is, the way my sump is setup, it settles out and does not get returned to the DT. IMO, the more flow to the sump, more suspended particles will be removed from the DT, as long as it's filtered out in the sump.

 

Alot of the things I do are basically what has been successful in the past for me and when I first started doing this PH's were really non existent so we realied heavily on the return pump for flow in the DT. I really never use my refugium to grow algae and am basically just using my sump/refugium for equipment and a pod refuge.While I realise that pods may prefer to live on algae it is not necessary IME to have a healthy pod population (except of course microalgaes) as they are oportunistic and will live pretty much anywhere.As far as flow I have never heard that pods would have a hard time living with a decent ammount of flow. I base this on observation of some I have seen holding on to glass (With some film algae I am sure) in the stream of a Koralia 1400 PH and the fact I have many pods in my sump running at 700 gph. I also realise that the flow I am running is surplus and really not needed with the addition of PH's in my sytem but I guess I am so happy with all the low power consumption of every other pump,PH,and lighting, that are available now I guess I was satisfied with that consumption.(Compared to what it was in the past) I do run an external pump (Iwaki) and have never had heat issues with my tank even living in S. Florida but of course heat is usually our enemy and relief in that regard would help others immensely especially if they are using MH's. If my Iwaki ever takes a dump (the last one ran for 9 years which also explains why I have never changed the size I was using) I am sure after reading this I will switch to a little smaller return pump.Thanks so much for your advise Powerman IMO it is worth much more then .02.
P.S. One more thing I would like to ask.You mention the skimmer benefitting from a lower flow rate.I understand completely what you are saying but am still unsure why the skimmer would be any more efficient with a slower flow.I know the water will be cleaner if it has longer contact with the skimmer but that would also mean it cleans the entire volume of water slower. In a closed system is there really that big a difference in how efficiently the skimmer removes the waste?

 

Awesome. I don't want to sound like it has to be "this" way or else... we all know there is a wide range of how to do things and it is all successful. And if power consumption or heat is not a problem then... well it is not a problem.

If a basement was an option for me I would not rule out using it just because of power to pump it. Equipment rooms are very nice compared to cramming everything under the tank. I went on a power diet with my setup and cut so much use I had to start using heaters... in that sense that added pump heat was not a waste because I had to make it up.... but that was only when the MH were off. When they were on I got away with no chiller and just a fan so overall it was a good thing.

The only difference for you is with your extra tanks you just have a place to see accumulation. Not a big problem. A small power head would be better to keep it suspended rather than say pushing 400 extra GPH through your whole system.... or get rid of the extra tanks.

I used to be a clean freak and aggressively filtered my water... eventually I stopped doing that and took out all my filters... I turned a power head on in the sump after lights out just to stir up all the waste and feed the corals in the display tank. There was a noticable improvment in my corals from all the food and I had no filters to clean and my sump stayed clean. My water was not clear of all particulate... but I did not mind and my corals were much much better for it. Just a thought.

 

Ya, and your thoughts are not far off mine.... what i have learned is that no matter how much I try to theorize what is the perfect way to do something... someone else can do the opposite and still have a great result.

I think I can get too worked up over the "perfect" pod habitat when in reallity they will grow anywhere whether you wan them to or not. There are those that have high flow fuges, but also some strong proponents of slow... I don't have proof one way or the other... it is just when I set mine up, I prefered the slow side of the middle. My fuge was not overfed with detritus and stayed clean. The pods seemed happy floating around, my macro grew... all things being equal, I will side on the side of moving as little water as I need to to accomplish what I need to accomplish. I use more efficient power heads to supply DT flow, I use a return pump to supply the skimmer and feed the fuge. That does not mean my way is the best or only way, that is just the criteria I use... and the "proper" flow needed may very well be high flow and that's fine by me.

... but you do not have to run pumps wide open... throttling is perfectly fine if you want to run a bigger pump than needed.

As far as skimmer efficiency... ya, you took that wrong. You are thinking correct. My point is if your skimmer only processes 200ghp... then running 1000gph through your sump is not accomplishing anything more than moving 800gph more. There will be some sort of skimmer efficiency that nobody has ever published or recorded. If it takes in 200gph, there will be some discharge of waste... not 100% will be captured the first time... in the end, it does not really matter. For common numbers say 200-300 gph on a 100g tank for proper rated skimmer... it is effectively filtering the system voume 2-3 times per hour... 24/7/365 it get the job done, end of story.

If you give it more water, it will not skim any more.... and if you give it less...well then ya, 100gph through its compartment, chances are the skimmer will get everything and pure water will be returned to the DT for arguments sake, but you are only cleaning 100 gph... over all you are not cleaning "more" and the skimmers "efficiency" has not changed one bit. Then that takes me back to the loose rule of only moving as much water as needed to accomplish what I want.

For real numbers I used Ehiem 1262 on my 120g total system volume that put out about 900gph with my head. I throttled that to about 650 gph... guesstimate. My fuge took about 100-150 gph, and the skimmer took the other 500 gph. My skimmer did about 350 gph and the drain 90'ed straight into the skimmer pump inlet... so we are talking maybe 150 gph making it by the skimmer, but the skimmer was not recircing any of it's output... I did not do everything to the gnats butt, but I minimized the extra. Minimizing is one thing, but I would always error on the side of more over less. Does that clear it up?

 

Perfectly!!Thanks for taking the time it is greatly appreciated!!!;D8)
Edit: and yeah commense throttling.LOL