new 180gal tank (need help)

[joshmcdowall]

hi im new to these forums and have found out lots of information from here as i am new to the salwater hobby..

i have just recieved my new 832 litre tank (about 183 imperial gallons) and i have a few questions regarding overflows, flow rates and hole sizes.

the tank i have now is made from regular 12mm float glass and is not tempered so it will be fine to drill the holes

i am think i will have 2 internal overflow boxes with standpipes and 2 return lines comming from the one return pump (still undecided which pump i need) 2 holes will be drilled on the base of the back of the tank and 2 up high on the back of the tank

i am thinking of making my sump out of my old 4 foot tank just with acrillic slides placed in it.

my questions are..

1. what sort of flow rate will be suitable for the return/overflow of a tank this size?

2. what size bulkheads/pipe sizes will i need for the returns and the overflows, and whats sizes holes will need to be drilled to match the return flow rate i will need

3. is there any good links around to makeing built-in internal overflow boxes with stand pipes out of acrylic? i cant seem to find a detailed one anywhere

4. is a 4 foot sump suitable for this size display tank?

5. is there anything else with this design you would recommend changing?

thankyou for any help you can give me.

[crvz]

Welcome to TRT!

1) Return rate should probably be in the 600-900 gallons per hour (sorry, don't use metric enough to convert in my head!). You'll want to have a good amount of flow in the tank, but it's better to use a closed loop or powerheads to achieve most of the flow, the return should be more dedicated to sump turnover.

2) I'd say 1" holes for the returns and drains should be enough, but you could go a bit bigger if you'd like.

3) www.melevsreef.com has a lot of acrylic advice. I've stolen enough info off of that to build a number of sumps.

4) a 4' sump should be plenty... do you have this already?

5) the only thing you may consider is building a "coast to coast" overflow instead of internals. This helps perform surface skimming, and you could even do this externally. Search for the term to learn more.

Good luck, look forward to seeing this come together!

[Loverotties]

Welcome to TRT!

[joshmcdowall]

thanks alot for the quick replies!

yes crvs i do already have the 4' tank

ive done a fair bit more research as to what you have told me and found out a coast to coast overflow is just and internal box at the back and on top part of the tank that runs lengthways with the tank?

ive think i am going to follow the design of this guys setup http://www.beananimal.com/projects/s...ow-system.aspx as it is quiet and safe..

but should i just use this method for the sump? and have a seperate overflow for the closed loop? because i was thinking if i had more drains in the same overflow for the closed loop sytem than the closed loop would steal all of the flow to the sump?

also on the closed loop system i was thinking of having 8 returns (4 spaced along the bottom of the tank and four spaced along the top just under the overflow).. or would that blow out all the surface scum away from the overflow box)? i was also thinking of using a motorized valve for these returns that alternate from one side of the to the other.

oh and will any more filtering other than the protein skimmer be neccesary? i am thinking of having a fair whack of live sand and live rock.

and again thanks for all the tips

[crvz]

I've found that the best filtration method is aggressive skimming and water changes, so I'm inclined to say that a protein skimmer is all you'll need. I'll sometimes use carbon, but not often.

In terms of the closed loop, you actually won't use an overflow or any of the sump water for that. With a closed loop, the idea is that the all the pipes are on a closed system. So say if you drill 8 holes on the back of the tank, you use 1 or 2 of them for sucking water into the pump, then the others for redistributing the water around the tank. This way there's no issue with losing power (all the water is contained) and you won't steal water from the sump, overflow, or other filtration systems.

That overflow box looks like a decent design, but I didnt read through most of the specifics. And you're right, the coast-to-coast is just an overflow box that's more horizontal than vertical, allowing you to pull more surface water down into the sump (the surface is where a lot of the junk will collect). Some folks even use an external coast-to-coast to not be in the way of the display, but that's tricky with an already built glass tank. Blowing the surface with the closer loop returns is a debatable option, on the one hand it disturbs what's collected, but on the other hand it helps
with oxygenation.

I've actually never run a coast-to-coast or closed loop system, so hopefully some others will chime in on this as well! Do you have any drawings or other images you can share of the build? A lot of times that can help in clearing things up.

[joshmcdowall]

ok ill try and see how my autocad skills are and get some drawings up to clear things up a bit

[crvz]

Originally Posted by joshmcdowall

ok ill try and see how my autocad skills are and get some drawings up to clear things up a bit

I usually use microsoft paint (it's pathetic, but it suffices), using a 10 pixel per inch rule and counting as I go. Please forget that I'm a mechanical engineer with autocad training. That slipped my mind many moons ago (and let's be honest, using paint is just sad).

[joshmcdowall]

ok well i figured out autocad was crap to use try and figure out so i resorted to good old paint..

heres a quick example.. (note.. there is no water lines or anything and this probably wont be exactly how i do it but it will give you rough idea as to what i am thinking)





my main goal was to have some of the returns pointing downwards under the the live rock to blow out all the crap up to the top..

i may change the CL returns to having 2 along the bottom and 2 along the top each side instead of 3 on the bottom and one on the top

is there anything i need to change?

ps.. sorry for the messyness

[joshmcdowall]

ive calculated the dimensions again and the display tank is actually 223 gallons

also.. would it be ok to have the drains from the closed loop system inside the coast to coast overflow.. as the closed loop system will be putting in as much water as it takes out it wont rob any water going to the sump, does this make sense?

[Mizer67]

One problem with feeding a close loop from an overflow is that with high suction and intakes near the surface, you will likely draw air into the pump and fill your display with microbubbles. Best to have close loop intakes a good way below the surface.

[crvz]

Originally Posted by Mizer67

One problem with feeding a close loop from an overflow is that with high suction and intakes near the surface, you will likely draw air into the pump and fill your display with microbubbles. Best to have close loop intakes a good way below the surface.

Yep, and the drains will be sucking water from the overflow, but returning it to the tank. The flow rate will probably be pretty high, maybe higher than the overflow can handle.

[joshmcdowall]

ok well i wont be doing that then will i i was just thinking it would of been a good place so it wouldnt be possible for the intakes to get clogged with anything. glad i havent started drilling yet. thank

anyways might get back to the drawing board.