Tank is level but water is not...

[unknownuza13]

I have been attempting to get my 300 up and running for some time now. I finally get the stand constructed and the tank on it filled up. At about 80% full I was having problems getting the dual overflows to siphon at the same rate. Last night I took some measurements on the tank. I measured the distance between the top of the tank and the water line. The difference between the left and right side of the tank was a half an inch lower on one side .... This would not be as much of a problem except that when a level is placed on top of the tank it is pretty damn close to perfect. I wasn't a science major in school but I'm pretty sure it is breaking a basic law. How could the tank be level at the top but the water levels be that off?

 

[bgkingd340]

im not sur but depending on your attachments one possibility would be to angle the intakes so that they are equal to each other

 

[WyldFya]

How long is the tank? If it is 6', 1/2" isn't much of a drop off, if 8' then really minor, speaking of level. Also, how big of a level are you using? If you have access check it against a 4' level or 6'.

 

[unknownuza13]

How long is the tank? If it is 6', 1/2" isn't much of a drop off, if 8' then really minor, speaking of level. Also, how big of a level are you using? If you have access check it against a 4' level or 6'.

The tank is 8' and the level in question was a small 6" or so one. I am going home for lunch with a 4' level. The only problem is the overflow on the one side starts a lot sooner and flows with more gusto and I am having problems balancing them out. This was all done at about 70-80% full tank capacity. I am assuming as the water level got closer to being full the overflow that was lagging would eventually catch up. If this is not the case maybe I could change the fitting on the one side to compensate for the 1/2".... Thanks both you guys for the input I will test it at lunch and report back..

 

[Oddball]

I take it you've already measured your weirs to verify they're the same height from the tank bottom?
Water seeks level. The tank cannot be level is the water line isn't (unless you have a gravitaional well - aka black hole hidden in your closet).
Recheck with another level. Drain and shim to true side-side, front-back, and corner-corner to properly level the tank and get the overflows to work correctly.

 

[WyldFya]

Boy it would be really nice to have a blackhole in the closet! When the annoying in-laws come over, I'd just tell them to go hang their coats in the closet!

The 4' level will be more accurate. For dual overflows make sure the bubble is dead center on the level.

 

[johnptc]

maybe the tank is not square !!

I have been attempting to get my 300 up and running for some time now. I finally get the stand constructed and the tank on it filled up. At about 80% full I was having problems getting the dual overflows to siphon at the same rate. Last night I took some measurements on the tank. I measured the distance between the top of the tank and the water line. The difference between the left and right side of the tank was a half an inch lower on one side .... This would not be as much of a problem except that when a level is placed on top of the tank it is pretty damn close to perfect. I wasn't a science major in school but I'm pretty sure it is breaking a basic law. How could the tank be level at the top but the water levels be that off?

 

[big train]

Yeah your tank is not leval a 6" leval on 8' is not going to be accurate and it may not be the stand it could be the floor that has a flaw did u strengthen the support under the house for a 300 gal?Also evan if it's on concrete that can have humps and dips in it meaning that u would have to put shims under the stand it happened to me in my garage but it was a easy fix.

 

[Jesse]

As Phil mentioned, check the distance from tank bottom to your overflow weirs to make sure they're equal. If not, you may need to lower one of them, presumably w/ a drill or narrow file, to match. I have dual HOB (CPR continuous siphon) overflows on my 360, but they have height adjusters built in to allow adjustment. Good luck!

 

[mostlycichlids]

I take it you've already measured your weirs to verify they're the same height from the tank bottom?
Water seeks level. The tank cannot be level is the water line isn't (unless you have a gravitaional well - aka black hole hidden in your closet).
Recheck with another level. Drain and shim to true side-side, front-back, and corner-corner to properly level the tank and get the overflows to work correctly.

I would have to agree with this if your water line is not level your tank is not level. You do not want a .5 in difference especially in that size tank. I always try to level my tanks perfect but is not always the case my 120 gallon is within 1/8 in from one side to the other that bothers me a little but It has been set up almost a year with no problems and that was as close as I could get it.