I have an ATO sensor in the sump set at the lowest level when the surge reservoir is completely full. This means that while I'm filling up the reservoir, the sump is artificially high. That's ok - the ATO just doesn't run during that time, but once it's full, if the water level is too low, the ATO kicks in and runs for 10 minutes (hold up time). I'm essentially running ATO intermittently whenever the reservoir is full, but that works really well.
Yeah, that should work fine. The ATO only has to keep salinity changes small enough so the critters don't notice, so having it functional part of the time would work just fine
YES. That's exactly what I designed it for. The ATO buckets are 7" high and I left 10" to allow clearance to work in there. A full reservoir weighs so much that my weight is a fraction in comparison.
How big is the new sump? Even if it's 100 gallons, say 1000 lbs including the tank, you could easily add 20% to that. Either way make sure the support can handle the weight. (I'm sure you've done this, but a failure here is more than a disaster!
I'm going to remove the middle two threaded rods and replace the supports with a 2x4 frame. The difficulty is in rethreading them. They were painful to install the first time, so I'm dreading that already. Doing all 4 is a nightmare, but it's worth rethinking.
How do you have them attached? Have you considered
coupling nuts? If you have to unthread the entire rod, could you use a drill?
I have two emergency overflows.
Good idea to have 2 overflows. In reality, you have to have the capacity to handle the peak flow into the tank, not the average flow. In your case, the peak flow is very high.
There's really no point running from the sump to the reservoir. It's less distance and height, so I get more flow starting from the overflow instead of going down to the sump. I do this now and it works pretty well. This also reduces the bubbles created from the sump emergency flows. In this new setup, the sump is really only there are a catch for the surge to flow down into. Without it, the tank level would fluctuate.
Ok - I didn't see a pump for that pipe. How do you keep it from vortexing and creating bubbles?
Not that I can think of unless a thick matt of chaeto were to break free... maybe I should have two openings in the top, just in case. I'll add a tee and a secondary elbow.
I wouldn't think that chaeto could clog it - the pipes are big enough and the flow strong enough that I would be really surprised.
There will be some. I have a slow flow UV that goes from sump to DT. I also have my skimmer return in the sump second stage and I'll be moving that up to my DT too. I have a GFO too, I might return that back to the DT. As far as an emergency drain to the sump, I don't see it doing anything that running to the DT won't do. I like having it in the DT so I can see it.
I don't have a feel for overall flow rates/patterns between the sump/display/surge tanks. Any concern that the flow/turnover in the bottom tank will be too low for filtering/water conditioning? Would it be better to have these up top since that's where the majority of the flow will be?
Yes. I designed the sump to be able to handle all the volume in the DT surge sections. I also have an aux sump on the side that can handle all the volume. If open fails open, it turns into an open loop where all the flow up becomes flow down - lots of bubbles, but no major harm. In fact, the flow rate will be the same as the pumps and less than a surge flow. In this case, the sump and DT would essentially be operating like a conventional tank.
:thumbsup:
Wow.. I'm at 2". At 3", the pipes become a significant part of the DT. The reduction in flow is actually ok. My current surge is probably excessively fast.
Ok - that's big enough!
A 2" open PVC pipe should be able to handle 5000gph. That's if all pumps are on at full blast. With 1" over it, it should support the flow. I think I'll add an emergency sensor at the surge tank top level JUST IN CASE! If it ever gets triggered, the pumps shut down.
My main concern was that it would likely be vortexing and entraining air, reducing the capacity. I don't have a good feel for whether this would be significant or not.
Interesting idea on the 'bubble trap' I can't totally picture it, but would the mesh tend to trap detritus? How much flow do you have through your sump? Would something similar, like a chute for the water to travel down on its way in reduce the bubbles?
