Overflow choice for 300 gallon acrylic tank

((FORDTECH))

Well-Known Member
View Badges
Joined
Jan 23, 2020
Messages
601
Reaction score
291
I recently picked up a used 300 gallon that previous owner was using with hang over back overflows and I wanted to upgrade to internal overflow style. After reading here and doing few searches on internet im not coming up with to many choices to choose from that I feel will be sufficient for such a large tank. Another option would be to install 2 over flows but not sure this would be best leaving me with 6 drain holes to run to sump complicating things. I have thought about the 36inch modular marine or installing 2 of the 24inch Fiji cube. I’m thinking using one of these 2 models because of the removable internal Side for the obvious easy access due to tank being acrylic top is not open and without removable inside part it would be impossible to clean inside or remove anything from inside it if need be. Here is pic of tank so you can see how I would not even be able to get a hand in a stationary inside mounted weir. Wondering if anyone has any pros and cons with either of these products besides fact of needing large sump to accommodate leak down past bulkheads in an event of power loss. Or does anyone have any other suggestions to use instead or any comments to add. Thanks for everyone’s help

image.jpg
 

R.Weller

Active Member
View Badges
Joined
Aug 5, 2019
Messages
165
Reaction score
185
Location
Lees Summit
We have a 300gal deep dimension. It is 72 x 36w x 24h. There are two corner overflows with holes drilled in the bottom glass. Each overflow has two holes for 1" & 1 1/2" PVC. We're using all four holes in a dual 'herbie' configuration. The return lines come over the back of the tank & are hidden by the canopy. This provides more than enough flow for the system.

A few questions for you. Is your tank drilled? If so, where are the holes & how many do you have? If not, is the tank glass & can it be drilled? All of the glass used on our tank is tempered & can no longer be drilled beyond what was done during the manufacturing process.
 

DaneGer21

Well-Known Member
View Badges
Joined
Jun 18, 2018
Messages
847
Reaction score
1,167
Location
Creston, 44217
I have a 60x36x24 and I use the 36” modular marine overflow, although I had my external box customized. I love it. Worth the money. They can also customize it however you want. Certain drain sizes, etc.
 

ca1ore

Valuable Member
View Badges
Joined
Oct 28, 2014
Messages
11,090
Reaction score
14,902
Location
Stamford, CT
36" modular marine will be more than enough for a 300 …. I am using it on my 450. Bought mine prior to them offering the removable skim box, so cannot say whether the display would drain down to the bottom of the through bulkheads. My guess is that it would happen very slowly and thus only an issue with a very long outage.

I had my acrylic tank made with this overflow in mind so have a couple of slots routed into the brace for skim box access. Build quality is excellent and as noted it can be customized to your specifications. Mine also cam with the external scupper box he same length as the internal skim box. I think newer models have a shorter external box. I like the extra length as it allowed me to add additional drains.
 

DaneGer21

Well-Known Member
View Badges
Joined
Jun 18, 2018
Messages
847
Reaction score
1,167
Location
Creston, 44217
36" modular marine will be more than enough for a 300 …. I am using it on my 450. Bought mine prior to them offering the removable skim box, so cannot say whether the display would drain down to the bottom of the through bulkheads. My guess is that it would happen very slowly and thus only an issue with a very long outage.
That is correct. Mine has the removable internal box, and my tank DOES very very very slowly drain while doing maintenance or during an outage. In my case, I bet it would take at least 24hrs+ to drain down to the bulkheads.
 
OP
((FORDTECH))

((FORDTECH))

Well-Known Member
View Badges
Joined
Jan 23, 2020
Messages
601
Reaction score
291
We have a 300gal deep dimension. It is 72 x 36w x 24h. There are two corner overflows with holes drilled in the bottom glass. Each overflow has two holes for 1" & 1 1/2" PVC. We're using all four holes in a dual 'herbie' configuration. The return lines come over the back of the tank & are hidden by the canopy. This provides more than enough flow for the system.

A few questions for you. Is your tank drilled? If so, where are the holes & how many do you have? If not, is the tank glass & can it be drilled? All of the glass used on our tank is tempered & can no longer be drilled beyond what was done during the manufacturing process.
Tank is acrylic and has 3 holes in back that I plan to patch seal and drill holes where needed
 
OP
((FORDTECH))

((FORDTECH))

Well-Known Member
View Badges
Joined
Jan 23, 2020
Messages
601
Reaction score
291
36" modular marine will be more than enough for a 300 …. I am using it on my 450. Bought mine prior to them offering the removable skim box, so cannot say whether the display would drain down to the bottom of the through bulkheads. My guess is that it would happen very slowly and thus only an issue with a very long outage.

I had my acrylic tank made with this overflow in mind so have a couple of slots routed into the brace for skim box access. Build quality is excellent and as noted it can be customized to your specifications. Mine also cam with the external scupper box he same length as the internal skim box. I think newer models have a shorter external box. I like the extra length as it allowed me to add additional drains.
What kind of addition mods would someone want on these already great overflows? More then 3 1 1/2Inch drains?
 
OP
((FORDTECH))

((FORDTECH))

Well-Known Member
View Badges
Joined
Jan 23, 2020
Messages
601
Reaction score
291
That is correct. Mine has the removable internal box, and my tank DOES very very very slowly drain while doing maintenance or during an outage. In my case, I bet it would take at least 24hrs+ to drain down to the bulkheads.
That’s good to know because if my power is off for more then few hours I will have huge issues with live stock I would not care about water on my floor with all the loss I would have
 
OP
((FORDTECH))

((FORDTECH))

Well-Known Member
View Badges
Joined
Jan 23, 2020
Messages
601
Reaction score
291
Does anyone here think 2 of the fiji box 24 inch overflows centered in tank with like 1 foot between them would be better then single 36inch modular marine ?
 
Top Shelf Aquatics

ca1ore

Valuable Member
View Badges
Joined
Oct 28, 2014
Messages
11,090
Reaction score
14,902
Location
Stamford, CT
What kind of addition mods would someone want on these already great overflows? More then 3 1 1/2Inch drains?
Limited only by one’s ingenuity ....

8E0D9CA7-0313-46E1-9E5E-3149F9A3AFD6.png


I don’t personally like how any of these things handle the emergency. We’re I so inclined to make my own I would do them differently.
 
Last edited:
OP
((FORDTECH))

((FORDTECH))

Well-Known Member
View Badges
Joined
Jan 23, 2020
Messages
601
Reaction score
291
Limited only by one’s ingenuity ....

8E0D9CA7-0313-46E1-9E5E-3149F9A3AFD6.png


I don’t personally like how any of these things handle the emergency. We’re I so inclined to make my own I would do them differently.
Well Technically I could do that mod myself if needed in the future. I’d assume that’s so it will safely flow more ? Or is it to just make it quieter ?
 
OP
((FORDTECH))

((FORDTECH))

Well-Known Member
View Badges
Joined
Jan 23, 2020
Messages
601
Reaction score
291
Limited only by one’s ingenuity ....

8E0D9CA7-0313-46E1-9E5E-3149F9A3AFD6.png


I don’t personally like how any of these things handle the emergency. We’re I so inclined to make my own I would do them differently.
How does the inside look please explain maybe I’d like the one I get to be like that :)
 

ca1ore

Valuable Member
View Badges
Joined
Oct 28, 2014
Messages
11,090
Reaction score
14,902
Location
Stamford, CT
I thought I had taken a picture of the insides of the external box ..... but cannot find it. Based on the picture I did post above, from right to left: 1” siphon drain to feed ATS, 1 1/2” emergency with pvc standpipe inside box upsized to 3”, 1 1/2” main siphon with strainer only, 1 1/2” secondary with u fitting and then 1” siphon drain to feed frag tank. I have a basement fish/sump room so figured I’d take advantage of gravity.
 
Reef Pro Corals
OP
((FORDTECH))

((FORDTECH))

Well-Known Member
View Badges
Joined
Jan 23, 2020
Messages
601
Reaction score
291
I thought I had taken a picture of the insides of the external box ..... but cannot find it. Based on the picture I did post above, from right to left: 1” siphon drain to feed ATS, 1 1/2” emergency with pvc standpipe inside box upsized to 3”, 1 1/2” main siphon with strainer only, 1 1/2” secondary with u fitting and then 1” siphon drain to feed frag tank. I have a basement fish/sump room so figured I’d take advantage of gravity.
So you had the outside box widened to 3inch what would that be for ? Also what ATS are you using mine only comes with 1/2 inlet barb? And doesn’t ATS need to be driven with pressure pump? How’s gravity feed working for you . This does not cause an issue due to unfiltered water being supplied to ATS ? Does your ATS then dump into a sock or a fleece roller filter or just a sump compartment not getting filtered? and mine requires about 600gph flow how did you go about getting proper flow threw the ATS? Sorry for all the questions but this sounds like something I’d like to do cause I already have the ATS but wasn’t sure how I was gunna run it yet.
 
OP
((FORDTECH))

((FORDTECH))

Well-Known Member
View Badges
Joined
Jan 23, 2020
Messages
601
Reaction score
291
Now I see you mean 3 foot so has room for extra drains. Scratch that part of my questions :)
 

ca1ore

Valuable Member
View Badges
Joined
Oct 28, 2014
Messages
11,090
Reaction score
14,902
Location
Stamford, CT
No, I meant 3 inches. I bought my MM overflow right as they were making a few design changes. Although I had the option to get the newer box, I chose the older one. I anticipated some drain issues with the removable skim box, so opted for the permanent one. I also liked the longer external box - as you can see , mine is the same length as the internal box. Newer models the external box is shorter. I did not have to have the box expanded to accommodate the 3" PVC on the emergency. It's not a 3" bulkhead, just a piece of 3" PVC welded to the standard 1 1/2" bulkhead. Upsizing the standpipe on the emergency means more inches of overflow and reduced chance of the box overflowing since the mouth of the emergency is quite close to the top rim of the external box.

I built my own ATS (there's a thread on in the DiY section). Been building my own for decades. It is designed to take a 1" water input. so easy enough to plumb from the overflow. Gravity provides plenty of pressure to equally distribute the water over the screen (though my display is a floor above, so lots of negative head pressure builds up), and I like that I don't have to run an additional pump. I do run an Apex flow sensor on the ATS feed, though eyeballing it works just as well. ATS doesn't care where the water comes from within the system. I don't use any socks.

FWIW, I also run my UV sterilizer off a siphon drain - that required a bit more thinking though :). I've got a build thread in the monster tank forum, Simons 450. Lots more pictures there.
 

Are most hobbyists using enough live rock these days?

  • Yes

    Votes: 14 23.0%
  • No

    Votes: 22 36.1%
  • Not sure

    Votes: 22 36.1%
  • Other (please explain)

    Votes: 3 4.9%

Online statistics

Members online
2,157
Guests online
4,620
Total visitors
6,777
Reef Brite the professionals choice
Top