Fluval 13.5g ATO Woes

[JoJosReef]

Disclaimer: type/brand of ATO should be irrelevant. This is a water level issue.

Running an ATO on my Fluval EVO 13.5g has been continually frustrating, and I'm mostly doing manual top offs. The issue seems to be the variable chamber 3 to chamber 1 (and maybe 2) water levels over time. Specs below:

Tank: Fluval EVO 13.5g
Chamber 1: Intank Media basket (currently only filter floss on top rack and others empty)
Chamber 2: Live rock rubble and Seachem Matrix (seeding)
Chamber 3: Sicce 1.0 and Aqueon 100w Preset heater

The Sicce is a strong pump. Starting with a new filter floss, I get a water level in Chamber 3 that is lower than Chambers 1 and 2. I understand that Chamber 3 (return chamber) is where most of the evaporation will occur, as the pump is going to maintain the DT at roughly the same level, as long as total water volume remains constant, as will Chambers 1 and 2.

Pic (pardon inaccuracy of fat fingers trying to draw arrows):

During the first day, the ATO refills pretty normally, as expected. By day 2, it is refilling too much, and the water level in Chamber 1 and the DT are rising. If I take the ATO off and monitor what is happening, it does something like this:

Pic (hypothetical Day 2+, where Chamber 3 level will run very low and chamber 1 will run higher--I didn't wait to take accurate pics):

I believe what is happening is that the filter floss gets gummed up and causes the return pump to pump more out of the third chamber than when there is unhindered flow past the filter floss. This usually happens after one day, when the filter floss starts to get brown and needs a rinse. After rinsing, it runs better, but not exactly as it did on Day 1. The net effect is that the ATO is refilling more often than it should. I was on a 4-day vacation and the housesitter wasn't tasked with cleaning the filter floss every day. I came back to a chamber 3 level that was nearly to the return pump and about 1/8th inch of buffer left in the DT and chamber 1.

In the end, this may be resolved by changing the filter floss more often than once a week and making sure to do daily pad rinsing, but I'm just wondering if anyone else had this issue? @GHOSTLY you have an ATO post for the Fluval 13.5g and a similar chamber 1 setup, I think. Have you noticed anything like this?

Thanks!

 

[JNalley]

just so I understand, when you came back from vacation, the water in chamber 3 was down too far, but the DT was up too high, right? If the problem is the filter floss, which I agree with you, that's precisely what it sounds like. Have you tried running coarser floss? (Most floss is a coarse upper layer and a fine lower layer, try tearing off the fine lower layer for a while and see how you fair).

 

[JoJosReef]

Yes, and forgot to mention that I told the petsitter to keep the ATO off when she told me it kept going and going, which is why chamber 3 was nearly down to the pump--otherwise, it would have been at the ATO fill line when I returned (and the tank would be spilling over).

Might try the coarse layer only and see how that works. Thanks!

 

[homer1475]

Quit buying that expensive filter floss......

Go to walmart and buy pillow stuffing(fiber fill). A huge bag that will last you about a year is like $5. Works 100 times better, and it doesn't get clogged up as fast.

Robot or human?

Used it in my biocube filter rack for years.

 

[MaxTremors]

Quit buying that expensive filter floss......

Go to walmart and buy pillow stuffing(fiber fill). A huge bag that will last you about a year is like $5. Works 100 times better, and it doesn't get clogged up as fast.

Robot or human?

Used it in my biocube filter rack for years.

I use the same stuff, have no problems with it getting clogged and hindering flow. Just put some in one of the compartments of your intank rack (don’t pack it in), and you’ll be good to go, you can either rinse it or toss it every couple days, I try to reuse it since it’s polyester and it seems the responsible thing to do, but even if you throw it away a bag will last you probably 6 months at least. Personally, I prefer the stuff from the craft store over the stuff sold specifically for aquariums (at least the brand Petco carries), the craft store stuff is coarser and stays together better.

 

[JoJosReef]

@homer1475 @MaxTremors where have you been all my life!? (Or last 3 minths at least)

Will go and get some fiber fill to test out and potentially replace the floss pads. Thanks!

 

[FishyFishFish]

I believe that the flow through the chambers is not sufficient to keep up with the output of the pump. Switching to a courser floss might help but what if you want to run additional media (e.g. carbon/chemipure etc) in the future?

I know a lot of people run the Sicce 1.0 but I run the Sicce 0.5 specifically to prevent this issue. Whilst I'm sure you don't want to buy a new pump, it could be a consideration if you don't have success with the coarser floss.