New Swiss 1900 liter (500G) Build

[Laith]

Nobody brave enough to have a go?

 

[Aimulator64]

Nobody brave enough to have a go?

While I am certainly not an engineer, I can understand your need to understand and validate your flow calculations. In my opinion, you are always much better off having a higher flow capacity than needed, as your return flow can be adjusted, along with your DC pump output flow. Trying to keep friction in mind, a 1.5 inch diameter pvc pipe can allow for roughly 2100 gph of water based on gravitational pressure. length doesn't provide much of a deviation, as friction reduction is minuscule over the short distance from the overflow box to your sump. An elbow will provide flow reduction, but if you use 45 degree fittings to make a 90, you will negate most of that consideration as well. As long as you have 2 1.5" diameter return pipes, I would consider your sump drain flow to be sufficient, as long as you are going for 4x-5x turnover, as you will be better off dialing down your drain flow and running at less than full capacity.

As far as your weir is concerned, consider that your 2 dimensional "air" surface area of a 1.5 inch opening is 1.77 square inches, if you were to have 2 returns, that gives you an opening total of 3.54 square inches for your drain. As long as your "tooth gaps" area adds up to at least that, you shouldn't have any issues with flow. I realize that this is a simplification as I do not have the technical mind to make it all make sense before my ADD derails my train of....OOOH SHINY! But really, I think that flow calculations are relatively unnecessary here. Lets say that your gaps are .25 inch by 1 inch, you have an area of .25 square inches. even 16 gaps is 4 square inches of open area, and you can always play it safe and place the top of your weir about .25 inches from the top of the tank as a safety in case you have a blockage along the grate. I am sure there are many other factors that could be considered, but as long as you put plenty of slots and have a couple drains, you won't have any issues in my opinion. Flow is adjustable, and 4x turnover is about all that is necessary for sump flow, as skimmers and reactors can't process much that much anyway.

Hopefully this response is even remotely related to your question, as I cannot even remember what it was at this point LOL

 

[Laith]

Thanks for that input!

The drain pipes will be 40mm ID (1.57") so I hope that I can get more than 2100gph down it... I may have gone wrong in my calculation somewhere because I got a result of around 6000gph. I liked that because I also wanted a higher flow capacity than needed. At 2100gph (just under 8000lph) I'll already be maxed out at around 4x sump flow. I'll redo my calculation to see. Don't want to get this wrong and have no wiggle room and not enough sump flow. It will be annoying to have to fix that after the fact!

My plan for returns is 2x 32mm (1.259"), each driven by a 8000lph (2100gph) return pump. With head pressure, these should still give 5-6000lph (1300-1600gph) each so more than enough.

 

[Laith]

One of the objectives of this build was automation... hence no more hauling buckets unless in an emergency. Therefore, here is how I'm going to setup the automatic water change and ATO on the tank:

(The two Litermeter pumps are actually connected together as well)

The fresh saltwater tank will hold about 430 liters which at 1% change a day will last 24 days. I could always reduce this to 0.5% water change per day which would double the number of days.

The RO/DI tank will hold 140 liters. This volume is less important as it will refill automatically. I just wanted it big enough so that the RO/DI unit wasn't running every day to fill it. I calculate that the 140 liters will last about five to ten days, depending on the time of year.

 

[Laith]

I've been asking for price quotes from several companies in my area and am surprised at the variation they suggest in terms of glass thickness for the size of tank I'm going to have built!

One criteria I have is that I do not want cross bracing across the top, just eurobracing around the sides at the top of the tank.

Out of five quotes I've received, two are offering 15mm, two are offering 19mm and one is offering 25mm (actually 2x 12mm with a laminated in between).

On this glass thickness calculator site, 15mm gives a safety factor of only 1.5, 19mm a safety factor of 2.5 and 25mm a safety factor of 4.5.

Of course there is a price difference between using different thicknesses, but this is less important for me than peace of mind.

Thoughts/opinions?

 

[McPuff]

Go thick.

 

[Laith]

Go thick.

Short and succinct!

I tend to agree and my instinct says go with the 25mm. But if 19mm can do it safely that would avoid spending a fortune on extra strong magnets for use on the 25mm. The Tunze Stream 3 have two magnet attachment points so each Stream requires two extra strong magnets at $100 each. So three or four Streams is $600-800 extra just for magnets.

However I'll pay that for the peace of mind. In any case at least one if not two of the Streams will be housed in Tunze rocks.

 

[McPuff]

Short and succinct!

I tend to agree and my instinct says go with the 25mm. But if 19mm can do it safely that would avoid spending a fortune on extra strong magnets for use on the 25mm. The Tunze Stream 3 have two magnet attachment points so each Stream requires two extra strong magnets at $100 each. So three or four Streams is $600-800 extra just for magnets.

However I'll pay that for the peace of mind. In any case at least one if not two of the Streams will be housed in Tunze rocks.

:0) Man, I had no idea the extra strong magnets were that expensive!! There are ways around that. The magnets are all waterproof so you could simply create a bracket out of thin acrylic and simply attach the stock Stream 3 with that. I may actually move mine onto the overflow since it's thinner and would allow me to run the pump at a higher flow rate. My experience with 1/2" glass... they will move on the glass at 100% and with the flow rectifier. Ended up with several gallons of saltwater on the carpet. Oops!

 

[Laith]

Tunze have confirmed to me that they do not as yet have a magnet option for the Stream 3s for 25mm glass . The one I was looking at does not work with the Stream 3s...

I think I may seriously look at using 19mm glass instead. Need to verify the safety factors... ;Bookworm

 

[Ashir Parekh]

Tunze have confirmed to me that they do not as yet have a magnet option for the Stream 3s for 25mm glass . The one I was looking at does not work with the Stream 3s...

I think I may seriously look at using 19mm glass instead. Need to verify the safety factors... ;Bookworm

They do have a rock that you could place stream 3 into. That is what i am currently looking at for my next build

 

[Laith]

Yes, and I will be using one or maybe two of those rocks as stated above. However, my initial plan was to have three or four Stream3s...

 

[McPuff]

Yes, and I will be using one or maybe two of those rocks as stated above. However, my initial plan was to have three or four Stream3s...

Consider using an alternate method to mount them, as I outlined above. Easy and will hold very well. The magnets are all sealed so no issues having them all in the tank. That would also make it easier to remove the pump for general maintenance.

 

[Laith]

@McPuff can you describe a bit more what the acrylic brackets would look like? They would hang in the tank from the top edge?

What about vibration?

Thanks!

 

[McPuff]

@McPuff can you describe a bit more what the acrylic brackets would look like? They would hang in the tank from the top edge?

What about vibration?

Thanks!

Yes, I envision something you can clamp to your frame/edge that simply provides an attachment point for the magnet mounts. Vibration is a legit concern. Could possible put a rubber bushing in between the acrylic and tank glass/acrylic panel. I'll have to check on your overflow design... but the easiest way would be attaching the pumps to the overflow box (though I think you have a low profile overflow...).

 

[Laith]

19mm glass (3/4") gives a safety factor of 2.7 actually (not 2.5 as I thought) for the planned size of the tank.

Any glass/aquarium builder specialists out there that could weigh in on whether this is an acceptable safety factor? Or do I really need to go to 25mm (1")?

 

[vetteguy53081]

Very nice!!

 

[Laith]

Very nice!!

Thanks for the vote of confidence.... but it's not up yet!

 

[Laith]

Anybody else have any inputs into glass thickness for this tank?

Will be ordering the glass within the next two weeks or so.

 

[Laith]

 

[Laith]

The above shipment was not for the glass .

So inputs on glass thickness still welcome...