Various questions for central sump / grow bed / multiple display tanks setup

[lightnb]

I'd like to get some thoughts on a central sump + grow beds + display tanks system that I'm working on.

I've got several display tanks: (3) 75's, a 90 and a 125. Most of the fish are larger or messy cichlids so high turnover is a must. The canisters just aren't cleaning the water enough for my liking and they are annoying to clean when you have five of them. I have about a 50% success rate of not forgetting the water is on and flooding the floor when doing water changes, and doing several tanks is a lot of work.

So my goals are:

1. One central filter that is easy to access and clean.
2. A filter that makes the water spotless with no floating particulate (high turnover).
3. Run the water through grow beds to remove nitrates and grow vegetables.
4. Automated water changer on the central sump.

That said, I've been working on getting this set up (playing "musical tanks" draining, cleaning and drilling one at a time) and have run into some questions/issues.

1. What is the "equilibrium" rate of 2" pvc pipe?

Pipe flow charts have siphon, pressure and gravity rates. But what happens when you connect two tanks together sitting at the same height, so adding water to tank A causes the water in tank B to rise at the same rate due to the "equilibrium" pipe connecting them under the water (fully submerged with no air in the line)? Is that flow rate the same as gravity or the same as siphon? Or something else?

2. When is a head not a head?

OK, so a pump sits in a sump 1' off the floor. The pump drives water 12 feet into the air, through a sealed pipe over your head. The pipe comes down the other side of the room and comes out at 5 feet. Is this 5 feet of head or 12 feet of head or something else? The pump has to fight 12 feet of gravity, but you have seven feet of gravity on the other side helping to pull water like a siphon. Does this negate the extra work on the front end?


3. Need some help with pump selection...

The total water volume of the finished system (excluding water in the pipes) will be 700 gallons. To get 10x turnover on the tanks, I would need a pump that can do 7000GPH at 5 foot head. I have an Ehiem 1262 on the grow beds now. Nice pump but slightly underpowered, and I don't even have the display tanks hooked up yet.

So, does it make more sense to do (7) Ehiem 1262's or one big monster pump? Considerations: cost of pump, energy efficiency, noise, risk of bursting into flames, etc. The bigger pumps that I'm seeing are all from brands I don't recognize and there's so much Chinese junk floating around these days. It would be good to get some guidance on what brands are reliable, will last a long time, can be tuned up (parts available) without trashing the whole thing, etc. And one pump or many?

4. Media

Ideally, I like to be able to go at least a month without cleaning the media, and for it to be very fast and simple to clean when it's time. I'm good on bio media. It's the mechanical that I'm having trouble with. I've seen a bunch of stuff in youtube videos, and I've tried a bunch of stuff myself and I haven't found something I'm happy with yet. Prefer something that can be quickly and throughly cleaned over disposable.

a. floor buffer pads - tried these, they work great in ponds where the water doesn't need to "sparkle". They are nearly impossible to clean though since they don't "squish" like foam.

b. "nu foam" - for furniture padding from a craft store. Seems to work well at removing fine particulate, but low flow rate causes the bypass to activate, and I only have 1/7th of the total system flow rate. Also hard to clean. I've tried various other foams but many have low flow rate.

c. The spongy stuff in a canister filter might work well if it came in big sheets for cheap instead of tiny strips for high prices. Would still need a polishing media though.

d. Quilt batting seems to work as a polisher, but is hard to clean and tends to come apart.

e. Ultimately, I need something that can do a great job at a high flow rate. Or- split the filter into a high turnover with course media only, and divert a small amount of the return through a polisher media?

5. Activated carbon

Will this mess up the grow beds/plants? Water does seem to look cleaner when I use it. Is it cheaper to buy from a water softener supply place in bulk?

There's more I'm forgetting, but this should give me a good start.

 

[carbene]

my setup is similiar to yours minus the sump as a growth bed. i have two display tanks (500g and 110gal) connected to a 110gal sump and a 60gal sump connected to that sump. i use 2x jebao dct15000 pumps. for media, i use pot scrubbers, ceramic rings, lava rock and a rubber ducky. no water change since i use drip.

for growth bed unless youre rich, i'd use lava rocks. i use them as growth bed for my pond and it does really well. dont use carbon, its a waste of money. your plants will do what the carbon does and more.

 

[fishguy306]

So you have a lot of parts, I will answer what I can as I'm setting up a large, central system as well. I will have a total water volume around 2000 gal by the time everything is running. Main tank will be 1000ish gal, with a 150 gal on the second floor, then in the fish room four 75 gal tanks, a 125 and two 150 gal sumps. All will be connected to these two sumps. At the moment only the sumps and the 150 are running.

1. What is the "equilibrium" rate of 2" pvc pipe?
It is not the same as gravity and no where near that of a siphon. I had a 2" line connecting my two sumps and found it to be no where near enough. Upon the initial setup I found one to be nearly overflowing the other nearly empty. I'm very glad I didn't fill them more to test. So I'd do a couple lines between to make sure.

2. When is a head not a head?
I think this answer will be that it depends. It is likely you will use 90* or bends after the down side into the tank, correct? So the pipe will still be full of water and backing up against the bends. I suspect it wont count as a full 5' down and I have no idea how to add it, but it still should be considered.

3. Need some help with pump selection...
Looks like you want to stick with internal? If so I suspect you will need to go with at least a few to move all that water if you don't want to spend a fortune. I'm going external with my pumps. I'm going to be using three Reeflo Hammerheads, each will do about 6000 GPH. I may add a fourth if three isn't enough. External it is easier to get higher outputs.

4. Media
I'm using a couple jacuzzi cartridge filters. The cartridges are big, probably 24" tall each I'd guess. Water must flow through it to proceed so they tend to do a pretty good job. Right now I have a low bioload, so they are lasting me a while, but I suspect I'll still be able to go weeks at a time with the two of them. To clean them I pull them out, stick the second set in. Then rinse the crud off the first set, then place them in a garbage with some bleach to soak. After a few days add the dechlorinator to remove the bleach, give them a rinse and they are good to go again.

5. Activated carbon
Many people don't use it at all. I know I don't, except starting in a couple day it'll be used in my drip system to remove chlorine. If your mechanical filter is up to par you shouldn't have issues that require it. My water (assuming I haven't just fed the fish) is very clear.

Hope this helps a bit!

 

[ragin_cajun]

..... and a rubber ducky.

That's why it works right there. If you guys don't have a rubber ducky in your sump, you just ain't doin' it right.

 

[Deadliestviper7]

When u do the piping,instead of using a pipe over your head,use a pipe to get it it to that height and make a waterfall that takes the water where u want it to go using gravity.

 

[lightnb]

So what do you guys use as the base for building your sump? And how do you size them? The sump I build for my 90 uses a 20 long with silicone baffles. This is fine for just the 90 with an Eheim 1262, but I don't think it can flow enough water for a Hammerhead which claims 5000 GPH @6' head.

I think the problems with small sumps are media surface area, and room to safely drill holes for outflow.

The Hammerhead has a 1.5" inlet, so you could drill one of those in a 20 long. But @5800GPH (zero head rating), it could drain a 20 long in about 12 seconds.

1. Is there any calculation on how many seconds of "reserve" water are needed for pump starts and stops?

2. Are there any media flow rate calculations? Like "1 square foot of media per 1000 GPH"? Since the return is gravity and not pressure (like a canister) you need enough surface area to handle the water volume.

3. What kind of container makes a good cheap base for high flow sump building? Is a 40B able to handle 7000 GPH with enough surface area for media?

I've seen a lot of trashcan/barrels as sumps, but it seems like an inefficient use of space and also hard to snugly fit square media into a round barrel.

4. Does it restrict the intake of a pump to have a tee on the intake to draw from multiple containers? ie. A 1.5" intake, connected to a 2" pipe via reducer and the 2" pipe has several 1" reducing tees connecting to containers. Would this hurt the pump? Would the draw on all tanks be even?

5. So those spa cartridges are round and plumbed in-line like a whole-house well filter? Do you put it before the pump? And does that restrict the intake when dirty?

 

[Fish Tank Travis]

Whew, let's take a breath. Lol

Ok, first I'd like to address the siphon affect on head height. You are spot on in that if you go up 12' and come down 7' it is actually 5' of net head height. Another user mentioned factoring in the elbows as restrictions and technically this is true, however, I don't think it is necessary because their affect on flow is not that great. We don't worry about them with the liquid refrigerant handling systems we build and those have been doing just fine.

Next, let's address your sump size. I have heard from many YouTube videos and other members' posts that you generally want to shoot for 20 gallons of sump capacity for every 100 gallons of system capacity. Some may agree with this and others may not, but it is what I like to recommend. This means that your total tank volume at 440 gallons should have about a 90 gallon sump. We need to know what you are going to go with so that we can give you recommendations on how to set it up. Recommendations for a large plastic tote will differ greatly than those of a 90 gallon aquarium, which will differ from the use of a few 55 gallon barrels. I like the idea of using an aquarium because it gives you a nice rectangular space that baffles can be attached to in order to make the most of it. I don't like the idea of totes because they don't allow for easy installation of baffles and then barrels just seem too tall to me to be easy to maintain. I recommend a 90 gallon aquarium for your sump, but I really think the extra length of a 125 will make for an even more useful sump.

As far as the pump(s) goes, I think it will be best for you to look into some smaller pool pumps for the kind of flow rate you want to achieve. Of course, this is not the only option, but in my opinion it is the best one. You can run it external so that it doesn't take up room in your sump.

For the media, it sounds like you have the bio figured out but need some suggestions on the mechanical. I think that wanting to have mechanical media that keeps the water very clear and only has to be changed/cleaned once a month is an impossibility. However, I think you can get set up so that your mechanical filtration is very easy to change by using filter socks. You can get them to filter down pretty fine and when they need changing you can very quickly swap them out and throw them in the washer. If you want a little bit more mechanical filtration beyond the filter socks then I recommend buying some rolls of filter floss pads and cutting a bunch of them out so that you can place them under the filter socks and swap them out when needed. This won't go anywhere near a month, and will probably need to be taken care of a few times a week, but it should only take a few minutes to do.

 

[fishguy306]

Ok, first I'd like to address the siphon affect on head height. You are spot on in that if you go up 12' and come down 7' it is actually 5' of net head height.

Another user mentioned factoring in the elbows as restrictions and technically this is true, however, I don't think it is necessary because their affect on flow is not that great.

Two things, while your net head may only be 5', you can calculate how much head you have on your system by that. Your pump still must be able to pump the water that 12' up to the ceiling. So your net head amount really doesn't mean much.

Also, 90* bends actually add a ton of head to the system. I'll be honest, I don't remember the exact number, however it is something like 2' of head per 90* corner on a 1.5" pipe. I can find exact numbers if you would like, but that is hardly insignificant.

 

[Fish Tank Travis]

Two things, while your net head may only be 5', you can calculate how much head you have on your system by that. Your pump still must be able to pump the water that 12' up to the ceiling. So your net head amount really doesn't mean much.

Also, 90* bends actually add a ton of head to the system. I'll be honest, I don't remember the exact number, however it is something like 2' of head per 90* corner on a 1.5" pipe. I can find exact numbers if you would like, but that is hardly insignificant.

I do agree that to start the pump it will have to pump the initial 12', however, once it gets to that point it will then have 7' of offsetting head height on the other side giving a net head height of 5'. This is VERY significant because it has a huge affect in the flow that the pump can produce. For example, a pump that might be near maxed out at 12' of head might only pump 5gph at the 12' head height. Then, the same pump can pump 1000gph at 5' of head height. Definitely NOT insignificant.

As far as the elbows, it really depends on the size of the lines that are used to determine the resistance they have on flow. At 1000gph, the elbow will have a greater flow resistance than it would at 250gph. In addition, a 1.5" elbow will have far less resistance on a 1000gph flow than a 1" elbow. You're right, it does have an affect. I am just usually in the practice of using lines large enough that it is fairly insignificant. If it adds an extra 1-2' of "head height" to my system, I can live with that because I have oversized my pumps to account for some extra "head loss." This is probably not something everybody does but I recommend to anyone asking to do this. You can always throttle back the flow with a valve or speed controller but you can get more flow than a pump is capable of.

 

[fishguy306]

I'll be honest, at this point the pump discussion is getting above my level, I'm not familiar enough with that sort of stuff, so I trust your information on it.

As for the elbows, I do agree. It depends on flow levels and pipe size. So many people try to get away with using small pipes in this hobby while wanting high flow. 1" pipes just kills flow rates. I'm using 2" on all my pipes, fittings cost a bunch which sucks, but I'm getting the most flow possible out of everything.