Well, I made the switch this weekend - or phase 1 at least. I removed my Ampmaster from my closed loop (good riddance!) and swapped out the big Sequence pump with a Blueline BL1100. The Blueline runs through my chiller and to a single return in the tank, and it's flowing about 600 gph. I used a Maxijet 1200 to feed my skimmer, which worked out perfectly (I didn't even have to adjust the gate valve).
So far, I am very encouraged by this change. Almost everything about it has been positive. First of all, my temperature without the lights on dropped 2 degrees last night, and it was one of the warmest nights we've had yet this year. I was halfway through the photocycle today before my chiller ran for the first time - and that's just because I don't have enough ventilation in my canopy. I have a few more fans I've been meaning to add, and if I don't add any other pumps I bet I can keep the chiller from running at all.
The flow through the tank from the smaller pump is very nice. I was a little worried about cutting back from 2 returns (1 in each corner) to just a single one, but it has worked out just fine. I'm still getting enough flow so there is no film on the surface, and it's still enough that I get the all-important "glimmer" lines from my halides. The majority of the tank's flow comes from a pair of Tunze 6000 Streams, and they sure get the job done.
The skimmer has only been running a few hours in this configuration, but it is a foaming beast - I've honestly never seen this much foam production out of my Deltec. And it already skimmed better than any skimmer I've had before - I can't wait to see what it does now. I dropped the Maxijet feed pump into the first chamber of the sump, where the raw overflow water comes in, so I'm getting the dirtiest water right to the skimmer. I don't know which factor was more important - feeding the skimmer from the first chamber, or the lower flow rate, but it's already obvious to me that it is skimming differently.
I've only noticed a couple of negatives, which should be easy to deal with. First is noise - this Blueline pump is much louder than my Sequence was. I'm almost sure that part of that is from the pump being new. I had one of these before, and I was going to return it because it was so loud, but after a week or two of "breakin" it quieted down considerably. So I'm hoping that will be the case here. Most of the noise is actually my sump resonating, so I am going to put a small piece of flex tubing between the pump and the hard plumbing to see if I can isolate the resonanace. I can do that since I'm not trying to run a massive return pump.
The other "negative" probably has nothing to do with this change. I have a lot more detritus settling on one side of the tank since I removed the closed loop. Well, that was the reason I added the closed loop in the first place, so I'm not surprised. But, I think the problem is because my aquascaping on that side of the tank is blocking a lot of the flow from the Tunze, so I am going to rework that side of the tank. The other side, where the Tunze isn't obstructed, looks very clean.
I am hoping that by fixing the aquascaping, I can avoid the need for the closed loop altogether. If I decide to stick with the closed loop, I doubt I will use the Sequence - it's just way too much. What I'm thinking about doing (only if I decided the CL is needed) is getting a small Eheim for the return, and move the Blueline pump to the closed loop. I could send it through the chiller on the CL, and then to an OM Squirt to alternate the flow among my 4 outlets. I think that would work very well, but I'm going to try it without the CL for awhile just to make sure I need one.
So as it stands now, I still have over 4000 gph (27x turnover) of flow and it only uses 100w total. Not too shabby!
Like if the water goes slow through the sump then the skimmer skims more junk out of less water....but if the sump is moving faster it takes less junk out of more water...get it:lol: Maybe thats why people have good success with low sump returns and fast ones.
