Daplatapus's upgrade
 

Well, I bit the bullet and bought Taionereefer's 210 gallon. So I went out to Van yesterday hoping to make the 12:45 ferry. FYI, don't think you can get on a ferry in the summer, on a Friday by getting there only an hour before it's supposed to sail.:(
Anyway, after being the 3rd to last vehicle to make it on the 3:10, we finally made it, met Taionereefer and family, loaded the tank up and ate a couple of their ice cream sandwiches. :D. Thanks again!
And what's a trip to the mainland without popping into J&L. Just bought a couple bulkheads and drooled over some Mp40's, but I thought I've pushed my wife's buttons enough this month so left with just the bulkheads in hand.
Missed the 7:30 ferry, Du'oh! But got on the 9:30 after a nice pizza and beer in horseshoe bay. Got home at 1:00 am, crashed, and got back up at 6:00 am to drive to Saltspring Island to help out a friend where I'm writing this. And guess where... waiting once again for the ferry because they're running 40min behind. Gotta love BC Ferries.
Anyway this will not be a quick switch over, but hopefully be fun. Pics to come :)

following along congrats on the upgrade

Congrats on the new box of water. With all that coin you are dropping at BC Ferries no wonder you left without the MP40. :lol:

Congrats on convincing her. One of the nicer tanks I have seen on here...so jealous. What a steal.... trust me when I say I am pouting. :wink:
Can't wait to see this come together for you.

Well, I was able to get some help and bring the tank into the basement where I'll work on it.
Preclean:
http://i1177.photobucket.com/albums/...s/P8132924.jpg

Post cleaning:
http://i1177.photobucket.com/albums/...s/P8132930.jpg

The tank originally comes with the 2 internal overflows. The drains are 1" durso's and 3/4" returns. I want to go with the herbie design though.
On my existing system I was stuck with existing holes and am actually running a 1 1/4" full siphon but at the bulkhead it reduces down to 3/4". I had originally run the 3/4" all the way but it couldn't keep up to the flow demand. That's when I used bushings to increase it to 1 1/4" on both sides of the bulkhead and it ended up being a bit overkill. My gate valve is probably only about 25% open.
So on this tank I'm thinking of using the 3/4" holes for my siphon but increased to 1" on either side of the bulkhead and use the 1" holes for my safety drains increased to either 1 1/4" or 1 1/2".
I really don't like the over the rim returns on my existing tank so I'm thinking of drilling 3 or 4 - 3/4" returns in the back of the tank. I did this with my cube and really like the results - it looks nice and clean. I've been able to drill the MIP-Locline adapter and have no issues with back siphoning when the power goes out. But it is only a 20 gallon cube, not a whole lot of pressure. If I drill the 3/4" holes as high as I can get them (which is roughly 1/2" down from the black plastic rim on the top of the tank) I'll be about 2 1/2" down from the top of the glass to the edge of the hole. And I was originally thinking 4 holes, 1 on either side of both overflow boxes. But I suppose I could get away with only 2 holes on the right side of the left overflow and the left side of the right overflow. The factory returns come with a splitter on them so in essence there is 4 returns anyway. Anybody see any issues with drilling that many holes? Or should I just go with the 2?

The other question I had (it just came back to me) is for those running dual siphon's. Is it hard to balance? Should I be tying them together and controlling with one gate valve? I know if I do it that way all the piping has to be exactly the same length, but it seems better to have redundancy with 2 separate drains. Just not sure how hard it will be to balance. What think you?

Any thoughts as to structural integrity of drilling 2 - 3/4" holes on the back pane 2 1/2" down from the rim?

drill slowly and carefully very little pressure and go with 4 return holes thi way you can adjust flow to dead areas your powerheads arent covering. try to design your return manifold insuch a way that yuo can have a syphon break to reuduce amount of back flow to sumpinpowerr failure

I would use the still use the larger hole for the main overflow and the smaller return hole for emergency. Depending on what you want keep, you can always dial it back if it's too much. This way you can fine tune it once it's all set.

As for the 2 in 1, I think you are better off doing a dual using a gate valve for better control.