water movement help

nw2rfing · #1 12/18/2007, 03:01 PM

ok, I have 75 gallon tank... I want some help in getting the right water movement in it. I am currently relying on the return pump, a maxi jet 1200 in the middle with a rotator end and a smaller pump (sorry dont know what it is).... is this enough? What doyou guys have in a similar size tank?

opiumpipez · #2 12/18/2007, 03:07 PM

i assume you have the 75g aga tank? or is this a custom 75g tank with dimensions other than 48x18?

if your tank is the former, what model is your return pump? i run an eheim 1260 which is about 600 gph, prob 400gph with 3 feet of head, tunze nanostream 6025 mod (900gph) and a vortech at 2000gph.

also, the amount of flow you need greatly depends on the corals you are/will be keeping.

can you tell if yuo have any dead spots in your tank?

nw2rfing · #3 12/18/2007, 03:51 PM

thanks for the reply opium....

ok, here comes a dumb question, what do you mean by 3 feet of head? I am assuming the distance the water travels from the pump in the sump to the inside of the main tank? ive heard this term bounced around, and i can only assume that thats what it is... anyways

I wish i could remember what I purchased 3 yrs ago of the top of my head but unfortunatley I cant... i do notice some dead spots when i feed... there are a couple of places the food doesnt get to, the back which is covered by rockwork, and all the way at the other end where the rock work ends...
oh, and the tank is your regular run of the mill rectangular tank you would get at the pet store
thanks for any help...

Mr James · #4 12/18/2007, 05:36 PM

To get flow, I would not change your return pump. I would add some powerheads or do a closed loop.

Providing us with what you plan to keep in the ta nk will help us know what to suggest. Also, what is your budget??

Here are some good key words to search on. Tunze Streams are nice, but pricey. MJ Mods are nice and cheap - I just ordered two of these. SEIO's are good, Hydor Koralia's are nice - I have a Koralia 4 in my 58g.

opiumpipez · #5 12/20/2007, 03:22 PM

head loss is basically the amount of pressure lost at a given height.

so for example. my eheim 1260 is rated at 640 gph (approx) at 0 head. then, as you increase the distance between the pump and the return bulkhead there will be a proportionate amount of pressure loss (due to gravity and distance).

if you choose stock SPS, you will need quite a bit of flow (anywhere between 40x and 80x your total tank volume).

so for example,

in my 75 gallon (85 gallons will sump and rock displacement) i am running a tunze nano stream (900gph), vortech (2700ggph) and return pump (400gph at 3ft head).

within the tank i have 4000gph flowing randomly. my TURNOVER is still at the 400gph. therefore, i have abuot 50x the amount of flow when compared to my tank volume.

if you choose to stock lps and softies, you can reduce your flow rate to probably 25-40x (check with other members, i have never owned an lps/softy dedicated tank)

anyhow, the flow that i have in my tank virtually eleminates all dead spots and does not kick up any sand.

let me know what your budgetary contraints are and stocking ideas and i can at least point you in the right direction.