Starting new tank and need help with calculations

[rlattof]

I’m in the very early stages of starting a 240gl tank (FO for now). I would love to NOT drill the tank if possible. Here’s what I need to know : what my flow rates will be ( in and out ) if using a HOB overflow (prob 1.5in drain, 50” height)? What should be a the proper flow rate for a 240 gl tank? If I have to drill the tanks for proper flow rate, who would I call ( not comfortable doing it myself)?

 

[Saltyreef]

Local glass company or a compitent LFS can drill.

Also, i think 10x turn over is what you want to aim for.

You need the GPM or LPM from the return pump you intend on using.
Pvc sizes will only tell u the max allowable rates.

Pump Turnover Calculator

Aquarium calculator; Estimate the time required for a pump to process a specified percentage of an aquarium system's water.

www.hamzasreef.com

 

[HuduVudu]

Avoiding drilling your tank will cause you a ton of headaches in the long run. It is safe to do and is relatively easy.

 

[Gtinnel]

I think 5-10x turnover is an appropriate range, but my recommendation would be to have the tank drilled instead of a hang on overflow. If anything causes you to lose siphon your tank will flood. There is a good reason that they are no longer popular in the hobby.
I've only drilled one tank (admittedly considerably smaller and cheaper than yours) but IME drilling a tank isn't hard. Just use the right bit, plenty of water, and don't put any pressure on the drill.

 

[Rubberfrog]

Drill baby, drill

 

[Justice4u2]

I’m in the very early stages of starting a 240gl tank (FO for now). I would love to NOT drill the tank if possible. Here’s what I need to know : what my flow rates will be ( in and out ) if using a HOB overflow (prob 1.5in drain, 50” height)? What should be a the proper flow rate for a 240 gl tank? If I have to drill the tanks for proper flow rate, who would I call ( not comfortable doing it myself)?

Welcome rlattof,

I personally do not use my return as my only form of flow in my display tank, and because of the items that I have in the sump; I do not have/want a high flow through the sump. I like the water to spend a little bit of time in there for cleaning. Noise is a factor to consider too, the higher the flow, the noisier it is. I have a 45-gallon DT and a 20-gallon sump. I run my return pump around 350 GPH.

However, your return flow from your sump is limited by your overflow that you choose (Go bigger than what you end up thinking that you will need). It will be rated by GPH (as I am sure you are aware). What size sump are you planning on using? What do you want to keep in there?

In addition, as far as flow to the sump goes, you can get the same flow with HOB vs drilled.

This is a personal opinion: HOB overflows don’t leave me with a “warm fuzzy feeling” I would be concerned that it would lose its siphon and spill over the display tank.

I know that I did not directly answer your question, I am sorry. But hopefully if you answer the questions above, someone with more experience with larger tanks will jump in with better advice.

 

[lpsouth1978]

If you are uncomfortable drilling the tank, I'm sure you could find another reefer near you that would be willing to help. It really is a very easy process, just takes some planning and patience.

If you go the drill route, I recommend and external overflow box. I personally like Exotic Marine systems, though there are several other quality ones out there that would work well. I would personally get the EMS 32" version for a 240g. It comes with a drill template and they even have a step by step video showing you how to drill the tank.

32" EMS overflow kit

 

[Gtinnel]

It also hasn't been mentioned yet but if you do end up deciding to drill your tank you need to make sure the glass isn't tempered.

 

[rlattof]

Welcome rlattof,

I personally do not use my return as my only form of flow in my display tank, and because of the items that I have in the sump; I do not have/want a high flow through the sump. I like the water to spend a little bit of time in there for cleaning. Noise is a factor to consider too, the higher the flow, the noisier it is. I have a 45-gallon DT and a 20-gallon sump. I run my return pump around 350 GPH.

However, your return flow from your sump is limited by your overflow that you choose (Go bigger than what you end up thinking that you will need). It will be rated by GPH (as I am sure you are aware). What size sump are you planning on using? What do you want to keep in there?

In addition, as far as flow to the sump goes, you can get the same flow with HOB vs drilled.

This is a personal opinion: HOB overflows don’t leave me with a “warm fuzzy feeling” I would be concerned that it would lose its siphon and spill over the display tank.

I know that I did not directly answer your question, I am sorry. But hopefully if you answer the questions above, someone with more experience with larger tanks will jump in with better advice.

Justice,

Thanks for the info. I'm trying to get a 1800GHP HOB overflow (Eshopps PF-1800). I am looking at the Seltz D 3200 (GPH) return pump (adjustable pump speed). Looking at a Triton 44 V2 sump.

 

[Justice4u2]

I did a quick search for the 1800GHP and it only stated what size tank that it was for, it did not state the GPH. I could assume that the "1800" in the name, that it is 1800 GPH, but that is mandatory information to know, why have us assume? I would expect that a company such as Eshopps to have this information quickly available. Also, depending on the sump that we have, we may not want a cookie cutter size suggestion based on our display tank. **Sorry for the rant**

I know that I touched on this on the last post and a few other also commented on drilling your tank, so I will not push that, I know that you have your reasons.

I would just make sure that whatever overflow you decide to get, it is rated for a few hundred gallons per hour more than your return pump. Your overflow will match what your return pump dumps into the DT, to that point. An example, if you get a return pump rated for 1600 GPH I would get an overflow rated for 1800 GPH.

I hope this helps

 

[rlattof]

I did a quick search for the 1800GHP and it only stated what size tank that it was for, it did not state the GPH. I could assume that the "1800" in the name, that it is 1800 GPH, but that is mandatory information to know, why have us assume? I would expect that a company such as Eshopps to have this information quickly available. Also, depending on the sump that we have, we may not want a cookie cutter size suggestion based on our display tank. **Sorry for the rant**

I know that I touched on this on the last post and a few other also commented on drilling your tank, so I will not push that, I know that you have your reasons.

I would just make sure that whatever overflow you decide to get, it is rated for a few hundred gallons per hour more than your return pump. Your overflow will match what your return pump dumps into the DT, to that point. An example, if you get a return pump rated for 1600 GPH I would get an overflow rated for 1800 GPH.

I hope this helps

I appreciate the help. Yes, the 1800 is referring to the GPH. That's why I was looking at the Seltz 3200 which is adjustable (DC motor with controller).

 

[Justice4u2]

Okay, great.
Know this, I am a worry wart. Even with the Seltz 3200 having an adjustable speed controller, I personally would not pair the two together. The worry wart in me would be afraid that if the electric kicked off, and then came back on the pump would/could reset to the max setting and cause a flood in the house.

 

[rlattof]

Okay, great.
Know this, I am a worry wart. Even with the Seltz 3200 having an adjustable speed controller, I personally would not pair the two together. The worry wart in me would be afraid that if the electric kicked off, and then came back on the pump would/could reset to the max setting and cause a flood in the house.

Good point. So focus on something around 2000GPH then to avoid that?

 

[Justice4u2]

Good point. So focus on something around 2000GPH then to avoid that?

If you are set on getting the Eshopps PF-1800, then i would focus on something around 1600GPH or less.

 

[rlattof]

If you are set on getting the Eshopps PF-1800, then i would focus on something around 1600GPH or less.

But shouldn't the return rate be aprox 10X the tank size?

 

[Justice4u2]

But shouldn't the return rate be aprox 10X the tank size?

But shouldn't the return rate be aprox 10X the tank size?

I am just trying to keep the water off your floor. If you want a higher return rate then you need to get a higher rated overflow.

I remember when I first started; I had a hard time wrapping my head around how the return and overflow worked. First, determine what you want the turnover rate of your sump to be. If you want a 10X turnover rate for a 240 gallon display tank = 2400 GPH. I would get an overflow that is rated for 2800 gph or higher, and a return pump rated for 2400 gph. I know that you will lose some flow do to head loss but I would not worry about it.
10X turnover rate is just a “rule of thumb”. However, I would base your return rate on other factors. What is the size of your sump? What are you keeping in your sump (refugium, protein skimmer, reactor, bio filter, filter floss)? The largest aquarium that I have had was a 90 gallon; I truly do not have experience with larger aquariums. I hope that if you answer the questions, then someone with more experience can help you out.

My current setup is a 45-gallon display tank with a 20-gallon sump. My return is around 250-300 GPH. I like to have the water to spend some time in the sump for cleaning. I do have a refugium with cheato and extra live rock, protein skimmer and a reactor for phosphates. I feel for the size of my display tank vs my sump and the goals that I want the sump to achieve, the lower flow rate works very well for my system. I do not know if this will translate to a larger tank, (I would think so) but it would be something to consider when deciding on turnover rate.

 

[Uncle99]

But shouldn't the return rate be aprox 10X the tank size?

I run my sump filtration at 5x, I really don’t want the water moving too quickly through the stages, slower is not a bad thing here.
As far as non drill applications, that’s a big risk.
When water stops, the sump must allow for any back flow.
When water starts, it should return to normal operating levels.
Make your system safe, now is the best time to do it right.

I have the same water volume as your planning, but my return height is 15’ mostly straight up. I use a Jebao 20000-DCT only at 60%, so for your distance a 10000lph would work well, some room to push some water into UV, maybe reactor.

Good luck on your system.

 

[rlattof]

So if my calculations are right and the overflow is actually 1800 GPH, if my return was 1300, plus taking into consideration the height pressure loss (5 ft @ 100 GPH per foot [500 GPH]), 90deg bends(4 @ 75GPH [300]), swing check valve (75 GPH) and unions (5 @ 5 GPH [25]), I would need 2200 GPH return pump to maintain 1800 in and 1300 out? So the Hydor 2400 controllable could work?