Looking For Advice: 2000gal Grow Out Tanks

HI all,
Looking to build a ~2000 gallon grow out tank!

Tanks: ~500 gallons, elevated conical bottoms.
Pump: 1 HP, 40GPM
Bead Filter: 1.65 cu ft, rated for 4000 gal filtration.
UV Sterilizer: 80 watt
Titanium In-line heater: 2KW

Attached is a simple picture of how I plan to plumb the system.

Would this system run okay? I'm concerned about the pump being able to push water from ground level to about ~4.5ft up.

Are vent holes needed before the intake of the pump? Thinking like a "T" connector just before the intake along the return pipe with a tall vertical PVC pipe attached to let air out?

Exciting to be tackling a bigger project! Any advice/criticism is welcome.

 

NavyChief20 would like this.

 

Quite the project. I can't contribute anything with my measly 75G tank, but best of luck and hope to see where this goes.

 

The only issue I can see is that you may want to add some kind of pipe between the 4 tanks to keep the water level even amongst all the tanks. As much as we want every output to be equal the won't be so one tank, probably one of the first 2 would start overflowing at some point.

 

mozzieman,
I just got to work and saw this. Let me get some work stuff knocked out then I'll help you out. This is one of those things that I do for a living. As a quick note, that 4.5' vertical you are talking about is called head loss. Your pump is rated to 2400gph but that is assuming zero friction and zero lift. So imagine the suction and return lines on the same plane. That's how they rate a pump at a given flow rate. When you change level your work on the system changes and reluctantly flow goes down as you know. Looks really intresting I'll take a closer look in a bit.

 

The only issue I can see is that you may want to add some kind of pipe between the 4 tanks to keep the water level even amongst all the tanks. As much as we want every output to be equal the won't be so one tank, probably one of the first 2 would start overflowing at some point.

Cool! Definitely will consider adding that to the build.

mozzieman,
I just got to work and saw this. Let me get some work stuff knocked out then I'll help you out. This is one of those things that I do for a living. As a quick note, that 4.5' vertical you are talking about is called head loss. Your pump is rated to 2400gph but that is assuming zero friction and zero lift. So imagine the suction and return lines on the same plane. That's how they rate a pump at a given flow rate. When you change level your work on the system changes and reluctantly flow goes down as you know. Looks really intresting I'll take a closer look in a bit.

Thanks! The pump/filter/uv parts I'm looking at said they have a 2" inlet/outlet and the in line heater said 1.5" inlet/outlet. Current guess is that the furthest tank is about ~25ft away from the pump, and ~4.5ft up from the ground!

 

Cool! Definitely will consider adding that to the build.



Thanks! The pump/filter/uv parts I'm looking at said they have a 2" inlet/outlet and the in line heater said 1.5" inlet/outlet. Current guess is that the furthest tank is about ~25ft away from the pump, and ~4.5ft up from the ground!

So you can solve the tank overflowing issue quite easily. The supply line (to pump) needs to come into the tank with a riser with a weir at the top. This will allow for a constant level rather than filling one more than the other. Since you have the tanks in series and it is an open system vice closed loop that is the easiest way to handle it. So you need a bulkhead for the bottom of each tank plus an isolation valve for each tank on the supply line.

Additionally you need an isolation valve on the supply and return lines prior to the pump and a union on each line on the pump side. This will allow for pump maintenance. To ensure minimum cavitation I would plumb in a smaller line on the pump side between supply and return. What this will do is provide a recirc line to send pump discharge back to the pump suction and you will ensure sufficient NPSH (net positive suction head). Put a valve in this line as well to throttle or secure flow.

The outlet of the pipe going into the tank you can either make an aerator or get a pond style aerator. This will cause more surface agitation as well as adding O2.
One other thing I would add and this is up to you is a tee with a valve and hose thread connection for each tank so you can drain independently. This will also require a valve for each tank on your upper line so you can also fill independently.

The recirculation line can be 3/4" NPS and that should be sufficient. Bear in mind your UV sterilization unit has a smaller size than pump discharge so that will cause a pressure change and velocity change on the system. One way of minimizing that effect is a branch line on the system return line so you can isolate it for maintenance or if not in use while still operating the system.

Out of curiosity what are you using as a biological and mechanical filter?

 

So you can solve the tank overflowing issue quite easily. The supply line (to pump) needs to come into the tank with a riser with a weir at the top. This will allow for a constant level rather than filling one more than the other. Since you have the tanks in series and it is an open system vice closed loop that is the easiest way to handle it. So you need a bulkhead for the bottom of each tank plus an isolation valve for each tank on the supply line.

Additionally you need an isolation valve on the supply and return lines prior to the pump and a union on each line on the pump side. This will allow for pump maintenance. To ensure minimum cavitation I would plumb in a smaller line on the pump side between supply and return. What this will do is provide a recirc line to send pump discharge back to the pump suction and you will ensure sufficient NPSH (net positive suction head). Put a valve in this line as well to throttle or secure flow.

The outlet of the pipe going into the tank you can either make an aerator or get a pond style aerator. This will cause more surface agitation as well as adding O2.
One other thing I would add and this is up to you is a tee with a valve and hose thread connection for each tank so you can drain independently. This will also require a valve for each tank on your upper line so you can also fill independently.

The recirculation line can be 3/4" NPS and that should be sufficient. Bear in mind your UV sterilization unit has a smaller size than pump discharge so that will cause a pressure change and velocity change on the system. One way of minimizing that effect is a branch line on the system return line so you can isolate it for maintenance or if not in use while still operating the system.

Out of curiosity what are you using as a biological and mechanical filter?

Thank you for the information! This is super helpful and exactly what I was looking for! I'm currently out this weekend, but I'll post again on Monday with links to all the supplies I'm thinking about ordering and maybe a better drawing now. I'm looking at getting most things through Pentair Aquatic Eco Systems!

 

Thank you for the information! This is super helpful and exactly what I was looking for! I'm currently out this weekend, but I'll post again on Monday with links to all the supplies I'm thinking about ordering and maybe a better drawing now. I'm looking at getting most things through Pentair Aquatic Eco Systems!

No problem. Hit me up when you need help.

 

So you can solve the tank overflowing issue quite easily. The supply line (to pump) needs to come into the tank with a riser with a weir at the top. This will allow for a constant level rather than filling one more than the other. Since you have the tanks in series and it is an open system vice closed loop that is the easiest way to handle it. So you need a bulkhead for the bottom of each tank plus an isolation valve for each tank on the supply line.

Additionally you need an isolation valve on the supply and return lines prior to the pump and a union on each line on the pump side. This will allow for pump maintenance. To ensure minimum cavitation I would plumb in a smaller line on the pump side between supply and return. What this will do is provide a recirc line to send pump discharge back to the pump suction and you will ensure sufficient NPSH (net positive suction head). Put a valve in this line as well to throttle or secure flow.

The outlet of the pipe going into the tank you can either make an aerator or get a pond style aerator. This will cause more surface agitation as well as adding O2.
One other thing I would add and this is up to you is a tee with a valve and hose thread connection for each tank so you can drain independently. This will also require a valve for each tank on your upper line so you can also fill independently.

The recirculation line can be 3/4" NPS and that should be sufficient. Bear in mind your UV sterilization unit has a smaller size than pump discharge so that will cause a pressure change and velocity change on the system. One way of minimizing that effect is a branch line on the system return line so you can isolate it for maintenance or if not in use while still operating the system.

Out of curiosity what are you using as a biological and mechanical filter?

I think I understand the tank overflowing issue. Similar to a gravity siphon, venturI drain? Here is the tank I am looking at purchasing (450gal). https://pentairaes.com/semi-square-tanks-with-cone-bottom.html
Is there a detailed guide on how to plumb a riser for a venturI drain? I've never done one before with a tank that has a 7" opening on the bottom, according to the diagram.

About NPSH. I'm confused what you meant by plumb in a smaller line on the pump side between supply and return.
The recirculation line is the movement of water between: pump > filters > tank > pump >...
Where the ">" would showcase the recirulation line correct?
I was originally going to use 2" or 1.5" PVC for the recirculation line. Would that be okay also?

And yes, I agree about the branching on the UV system, adding a blower/airstones for aeration, and adding ball valves / unions where needed!

Here are a couple links to the filters I've been looking at. With everything working on a 120V, 60Hz. I thought this system would be easy to set up.
Model #930084: Pump, Bead Filter, UV filter bundle:
Model #S21-A: Air Blower:
Model #TIL2: 2KW in line heater:

Thanks for taking your time to help me out!

 

I think I understand the tank overflowing issue. Similar to a gravity siphon, venturI drain? Here is the tank I am looking at purchasing (450gal). https://pentairaes.com/semi-square-tanks-with-cone-bottom.html
Is there a detailed guide on how to plumb a riser for a venturI drain? I've never done one before with a tank that has a 7" opening on the bottom, according to the diagram.

About NPSH. I'm confused what you meant by plumb in a smaller line on the pump side between supply and return.
The recirculation line is the movement of water between: pump > filters > tank > pump >...
Where the ">" would showcase the recirulation line correct?
I was originally going to use 2" or 1.5" PVC for the recirculation line. Would that be okay also?

And yes, I agree about the branching on the UV system, adding a blower/airstones for aeration, and adding ball valves / unions where needed!

Here are a couple links to the filters I've been looking at. With everything working on a 120V, 60Hz. I thought this system would be easy to set up.
Model #930084: Pump, Bead Filter, UV filter bundle:
Model #S21-A: Air Blower:
Model #TIL2: 2KW in line heater:

Thanks for taking your time to help me out!

Look at this basic diagram. Recirc line is to minimize cavitation of the pump.

 

remember any long straight legs of pipe will need support due to water weight. Using 45 degree angles when you can is better because it minimizes head loss and friction build up in the system. Friction will translate to heat and you want to be able to control all heat input and output. Depending on size of the pipe you might want to consider a desurger or a feed tank. Feed tank is just a sealed water tank that will be for makeup water and has a membrane or vent on top to bleed off gases as they come out of solution