Hi all... as a lot of you know, I had a lot of problems getting my "beloved" sump filter up and running. I know have a nicely cycled tank and a QUIET filter. The first level of media in my sump is sheets of filter material, 2nd level bio balls, 3rd level sponge.

Here's my question. Every couple of weeks, sometimes less than 2 weeks, the water level in the tank starts to RISE and I get a little "oil" slick around the top of the intake in the tank. Usually I have to rinse (not in tap water) the sheets of filter material and the problems goes away.

Is this normal?
Is this caused by the water not being able to get thru the sheets?

I have no idea what the little slick is but it goes away too. I would expect to see water levels drop in the sump due to evaporation (which I see a little of).

Pic of the sump as a reminder.



BTW.. miss ya all !
Brooksie

The oil slick comes from food as a lot of the food contains fat, probably not much, but enough that it builds up after a while and floats on the surface as a slick. Obviously it will then stick to anything like oil would. I wouldn't marry about it.

I use a foam slab as topping in my prefilter, together with cottonwool.
I have to replace the cotton weekly and have to rince the slab as well.
In my case it's purely mechanical filtration, but the foam will become slimy and will not let the water pass quickly enough.
Waterlevel in the overflow will be equal to the waterlevel in the tank if i don't clean that out properly and frequently.
Although i got an extra tube from top to bottom, just to make sure the water can enter the sump at all times.
2 weeks is not that bad!

What kind of overflow do you have siphoning water from the tank?
Is it a drilled tank, overflow with U-tubes or a CPR?

^ is the reason why I would only recommend a sump with a proper wier setup. A wier setup will prevent the water level from the display from rising (as the wier provides enough capacity to handle the increases).

A wier acts as an indicator for your mechanical filtration - if it is preventing water flow the water level in your wier will rise, and when it gets close to the top you know it is time to clean it out.

If you dont have a wier (ie overflow pipes etc) then you can actually run the risk of your display overflowing... ouch...

That would be bad indeed.
That would mean short circuiting of my equipment for sure.
btw reeftofresh, what's a CPR?

A wier is what I have. It's also worth mentioning that when you first design the sump , calculate how much water enters the sump after you switch off your pumps i.e. how much water continues to flow out of the tank before it drops below the top of the wier. Two reasons, first you certainly don't want to overfill your sump and then find you flood the cabinet when you switch your pumps off. But also you want to maximize the efficiency of your sump, in other words there is no point in having a sump if it's half empty. You have also got to make sure that you always have enough water to cover your pumps, remember that you will notice the evaporation in the sump and not the tank

Noddy wrote:


CPR is first aid, you know mouth to mouth, chest compressions. Christ he must have short circuited his gear too.

Goob_Scooper wrote:


could you explain how using an overflow pipe will run the risk of overflowing your display tank. i know that if your overflow gets plugged the sump will empty into the tank and thus overflow it but the same will hold true with any setup. im curious as to what exactly you mean by this statement....

marcus wrote:


A five-year-old boy walks into his parents’ bedroom just as his full-chested mom is about to put on her bra.

“What are those, Mommy?” he asks, pointing to her breasts.

“Oh, those are balloons, Jimmy. When women die, they inflate and float you up to Heaven.”

The following week, Jimmy runs into the kitchen where his mother is preparing lunch.

“Mommy, come quick, Aunt Betty is dying!” cries the little boy.

“What do you mean she’s dying??” asks Mommy.

“She’s lying on the floor in the basement with her balloons out…Daddy’s trying to blow them up so she’ll go to Heaven, and she keeps yelling “Oh God, I’m coming!”

that's one joke i'll remember!

I got a 1 inch tube that runs through the corner of my prefilter in the corner of the tank.
It 's top is at the height of the maximum waterlevel in the tank.
It runs to the bottom of the prefilter and sticks out a little bit under the filtermedia.
If the prefilter gets clogged, the waterlevel will rise in the prefilter and eventually starts flowing directly into the tube, and thus into the sump.
That way the water will allways be circulating even if i would change and clean the prefilter too late.
It means any dirt will also flow directly into the sump, so i'm usually in time to keep that from happening.
Maybe Goobs meant the same thing...

necromancer4 wrote:


The risk is similar with any sump setup, however there is increased risk with an overflow pipe as:

- Unlike a wier you cannot easily see the increasing water level. Even if you do notice the decreaing water level in sump, for new players they may think that this is evaporation and add more water...

- An averflow pipe generally holds less than half the water capacity of a wier (this is variable of course - but talking gneralities here) if the overflow gets plugged/ restricted then it gives you a lot less time to respond.

As exampe for me is that my woer is plumbed into a rotating spray bar. This spray bar slowly gets blocked with large debris, and I can see easily the increasing water level in my wier, as it approaches half way I clean it out and it returns to normal.

If I had a overflow pipe - I would not be able to see the decreased flow through the pipe (and wouldnt notice the increased water level because of the hood being significantly lower than the water line). All i would notice was if I checked on the sump (not something I so regularly). If I did check and notised the lower water level in sump (especially if I was new) I may put it down to evaporation alone, add more water and BOOM overflow in the making!