I'm confused...

[tmann51]

Last week I finished a total start-over of my 75-gallon Marineland corner overflow marine tank. Along with the complete cleanout of the sand (concreted) and rock covered with GHA came new hard plumbing and new equipment. I really wanted to ditch the filter socks and go modern, so I got a Trigger Platinum 26 with the V.2 roller fleece system, and a Hydros Launch to replace my ancient Digital Aquatics control system (that's right, old school).
With the new sump and hard plumbing in place, 60# of Carib-Sea Bahamas Oolite and lots of Life-Rock and base rock, I mixed and added 78 gallons of Tropic Marin Pro salt water (RO DI) and added it to the tank which filled the tank and the sump to safe levels, no leaks either.
Then the troubles started. It is obvious that it is much easier to thread the fleece into this roller dry than wet, maybe the fleece roller would not even be needed in a brand-new set up at all or a skimmer either. I'd installed my Octo Varios 4 in the return area of the sump, so I set it to max and turned everything on. I'd set up the V.2 roller fleece with the optical sensors set to activate when the fleece area water was rising to advance the fleece and to shut off when the return pump shut off, all good.
Nope, as the fleece holds back water as it "clogs" and before it advances, it lowers the water in the adjustable-depth skimmer section and therefore the water going into the return pump. The return pump area water drops as the pump fills the DT to almost overflowing. My most confusing thing is at tank water has stopped going drown the overflow assembly in the corner overflow until the tank water is WAY high. I've tried reducing the flow of the return pump, adjusting the depth to the skimmer section "overflow gate", and have removed several gallons of water. Nothing has really worked on a permanent basis. I certainly can't consider any kind of ATO system with this going on. Also, I've gone through an entire roll of fleece in 5 days! This fleece is hard to find and expensive. Help, I guess, I'm looking for quick solutions.
Thanks.

 

[griss]

Can you post some pictures? I'm a visual person and having trouble picturing what is going on. That said, I've never used a fleece roller before and it sounds like that is what the issue is. What happens if you remove the fleece roller?

 

[tmann51]

Can you post some pictures? I'm a visual person and having trouble picturing what is going on. That said, I've never used a fleece roller before and it sounds like that is what the issue is. What happens if you remove the fleece roller?

I'll work on the pictures. I've never tried it w/o the fleece roller, I just installed all of this last Wednesday. But, yes, here's a hint, I'd installed a new roll of fleece last night. As per Trigger Systems instructions by stapling the end of the old roll to the beginning of the new roll, 2 staples, 1 each edge, the fleece advanced until it got to the splice but then a gap at the splice let the tank water bypass through the gap thus stopping the further advance of the fleece roll. The water in the "fleece chamber" did not rise to activate the sensor to advance the roll, essentially, the fleece roller was removed. The water levels in the sump (skimmer and return pump) and the DT seemed to have remained stable, but then, how would I know? Of course, with the fleece bypassed, it did not advance and get used up. This roller system also has the option of not using the (3) optical sensors and setting a timer to regularly advance the fleece but I'd like to see if anyone else has this Trigger roller fleece system and uses timers as well as the settings that they employ to do the same task as the sensors do but perhaps better.
Thanks

 

[tmann51]

Left Photo=DT corner overflow (stable levels). Center photo= left side where tank overflow enters the sump, right side back of roller fleece. Right photo=left top fleece roller system above fleece section (2 optical sensors in chamber), skimmer in skimmer section, return pump in return pump section (1 optical sensor). In last photo, note water levels in each section.
Thanks

 

[wvned]

Do you have a hole or holes to vent air from your drain at the top? The fact that the water level in the corner overflow is the same as the tank level means you are pushing the drain to the max.

 

[griss]

Do you have a hole or holes to vent air from your drain at the top? The fact that the water level in the corner overflow is the same as the tank level means you are pushing the drain to the max.

I think the PVC (the two 90 degree elbows) are the top of the overflow so, that's the lowest point the overflow can drain to. Also if, like you said, there's no way to vent the air, the overflow pvc is likely creating a siphon at some point which could be part of the issue with unstable water levels.

ETA - Picture of what I'm talking about.

 

[wvned]

I think the PVC (the two 90 degree elbows) are the top of the overflow so, that's the lowest point the overflow can drain to. Also if, like you said, there's no way to vent the air, the overflow pvc is likely creating a siphon at some point which could be part of the issue with unstable water levels.

ETA - Picture of what I'm talking about.

View attachment 32414911

There should be a vent hole where your arrow is pointing.
See the second pic he posted with all the foaming at the bottom.

If you don't vent it you get surging. It goes full siphon until it sucks air and stops and then the water will rise in the overflow until gravity starts it down and repeat.

You cant run a single overflow full siphon. You never get a stable water level. The Marineland ones shipped with tanks work really well.
The water runs over the bottom of the 2 90s and that sets the level you get in thew overflow.

This tank probably had a kit that came with it.

There should also be an anti drain back hole in the return just under the 90. If it splashes, mine did so I covered it with a very course bit of filter material.

Interior Drain Plumbing The drain plumbing consists of two elbows, a 1-1/2”drain pipe, a reducer fitting, a piece of 1” pipe, and the 1”bulkhead. One of the elbows is drilled with large holes in the sides that allow relief flow into the drain. There is also a small hole on top that has a short length of small tube in the top. The small tube is there to help allow water to enter into the top of the elbow so that there is no restriction. It’s important that this tube remain free of any obstructions. It’s also important that the tube extend very little into the inside wall of the bulkhead. It’s best for it to simply be flush with the inside wall and should not be pushed so far in that it remains in the water stream. The Corner-Flo TM overflow and plumbing are rated for700gph and this is not affected by the fact that the drain necks down to 1” as it enters into the bulkhead. Higher flow rates can be achieved, but 700gph has been established as the optimal flow rate.

My 180 has 2 of these.

This is made by Aqeon but the idea is the same
The holes in the sides are about 1/4-3/8 inch. and the one in the top 1/8 or fit a small bit of airline tube about 1 inch long.