Red Sea XXL 750

frank-lloyd-reefer · Mar 28, 2022

Hi all,

I've had a handful of reef tanks over the years but have finally landed on a system that will please me size-wise: A Red Sea XXL 750. With visual aesthetics out of the way, my biggest requirement is automation. I bounce between two homes. While they're just an hour apart from one another, a lot can happen in an hour.

Additionally, one of my homes is architecturally significant, no pressure there yeahhh.

And oh, I should also note that I'm looking for a tank heavy on the SPS.

Starting with the system details I've thus far completed:

Red Sea XXL 750 v3
Three Neptune Sky lights utilizing Ecotech mounts
Neptune Apex + Trident
Neptune Cor-20 return pump. A second pump, Sicce SDC 9.0, is lost in the mail somewhere.
Two 500w Helio heaters
Three Neptune DOS pumps for adding my Red Sea recipe ingredients
Reef Octopus Elite 200-Int protein skimmer
Avast ATO that pulls RODI water from an external 12g reservoir into the 7.5g Red Sea reservoir
Two Neptune leak detectors
Two Neptune Wav powerheads
Two Neptune Energy Bars
CaribSea special grade dry sand + arag-alive
CaribSea dry dive rock

Shortly I will be posting some details + video regarding the above.

What is still outstanding:

Tampa Bay Saltwater live rock + live sand (picking up at airport tomorrow, 3/29)
Neptune flow sensors (given reviews I'm a little on the fence with this one)
Two more leak detectors and Neptune optical sensors for redundancy
Three more Neptune DOS pumps for trace additives and water changes
Running RODI lines in my ceiling to fill and pull from a 32g garbage can in an unused shower for water changes
Installing the solenoid on the source line for my RODI boost pump
Overall cable management + Trident placement
Address Avast ATO issues I'm having (pressure sensor losing pressure)
The remaining DOS closet mounts (picking up additional supplies today, 3/28)

It's been quite a journey thus far. I will provide updates as outstanding tasks are completed.

blaxsun · Mar 28, 2022

Love your fish room. How much convincing did that take?

frank-lloyd-reefer · Mar 29, 2022

I'm a single dad to two young girls who enable me. We started out looking at the 425, then crept our way up to the 750.

frank-lloyd-reefer · Mar 29, 2022

Thanks to a couple threads I was able to get the stand out from underneath the tank on the pallet by myself. This was great because had I left anything else up to the movers I'm sure they would have done more damage. I requested four movers and sent them a video of three large Australian dudes trying to move the tank. Movers sent two scrawny guys who nearly dropped it multiple times. Hearing "oh my god, oh my god I'm going to drop it!!!" and watching one of the movers drop to his knees was pretty harrowing. Even with a third guy they could barely manage. Additionally they did some serious damage to my hardwood floor. Moral of the story: you'll need four movers for the XXL 750. A very hard four.

frank-lloyd-reefer · Mar 30, 2022

I'd put the stand together the night before. It was pretty straightforward, similar to IKEA furniture. You'll definitely want to use a drill though. Loads of screwing. One confusing bit about the instructions was the orientation of the tank in each step. It flipped around here and there so getting the plumbing right involved reorienting per whatever step I was on.

Also, the sump needs to be placed in the stand prior to installing the support beam. I'd hoped to be able get it in by myself, but the sump came inside the tank and there was no way I was getting that out solo.

In the video I said I was missing the silencer, but I was wrong, I later found it so that was all good.

Mid-stand build:

Stand complete-ish:

Tank is on the stand:

Things were looking good! And then some drama: I could see a visible gap between the tank and the stand. I could do this:

frank-lloyd-reefer · Mar 31, 2022

There are a bunch of threads about the "paper test" and pre-V3 Red Sea 750s. It seemed like there wouldn't be any issues, but I reached out to Manny just to be sure. He agreed, but also recommended I submit a ticket with Red Sea for the sake of a paper trail if things went horribly wrong. Red Sea gave me the green light and I started to fill the tank. Nothing went horribly wrong.

Below is a picture of my RODI setup. I tapped into my source water line in the wet bar, and added a saddle for reject water. Then I drilled a couple holes, one for power to my booster pump (Aquatec 8800) and one to supply water to the adjacent 12g reservoir. That resrvoir then feeds the internal 7.5g reservoir beneath the tank. The only step that is automated is filling the 7.5g reservoir. For this I am using an Avast ATO unit. For redundancy I've got a Neptune optical sensor in case the Avast doesn't stop pumping. If both of those are down then a Neptune leak sensor will let me know I am screwed. Adding a solenoid to complete the automation remains on the list of things to do.

Filling the tank, a brief lay of the land:

blaxsun · Mar 31, 2022

If this is a Red Sea 750 XXl v3 with the aluminum brace and steel lip on the stand, you'll be fine. Are you planning to run a UV sterilizer?

Soilworker · Apr 4, 2022

Following along, getting a 625XXL myself here in a few weeks.

Looking great so far!

frank-lloyd-reefer · Apr 12, 2022

Alright, after a wicked bout of food poisoning and catching up at work, I'm back on track..

Yep, it's the V3 stand. Once the tank was filled the weird gap vanished.

I was looking at UV sterilizers, yes. I think I could fit one in and not block access to the skimmer if I pull out the Reefer ATO tank (which I've since decided to do because the float valve in the sump already got clogged when I wasn't here) and things got dicey for a bit. I tried to clean it with a pin but it was stuck solid. I knew the thing was prone to risk but dang that was fast. I now have my water from the exterior reservoir going directly to the return chamber. The Avast pressure sensor and the optical sensor are in there as well. Been really smooth sailing since.

blaxsun · Apr 12, 2022

I mounted a 57-watt in mine with no issues (and the ATO still fits). I'm almost a year in without any issues on the float (I took it out once and it was ridiculously clean). I'm planning to keep my 7-gallon gravity ATO and add an IM 15-gallon reservoir with Tunze ATO beside the stand (giving me about 22-gallons of RO).

frank-lloyd-reefer · Apr 12, 2022

See, I really liked that setup. I actually boiled my float (when I knew it was a goner) and only after that could I get some air thru. I have a prohibitively large skimmer, which had a domino effect of unfortunate sump real estate circumstances. I love it, but probably would have gone down a notch there. I'm lucky to have the wet bar nearby that my 12g external reservoir can hide away in. But I'm going to need more. 12g isn't enough.

frank-lloyd-reefer · Apr 12, 2022

When I filled the tank I was really surprised at how quiet everything was. Feels like my tiny, old 39g with CFC and loud-butt fan was way more noisy. When I had that that one it was in my office next to my bedroom, and I needed to keep both doors closed at night if I wanted to fall asleep. Here my bedroom is directly above the tank and all I have is silence. I've seen a lot of posts where a lot of effort was required to get to a stable, quiet hum. I think I might have the advantage here as the dial on my Viking stove is somehow far more janky than the Red Sea valve. Used to closing my eyes and seeing how things shake out.

There were three places that created all of the noise:

Overflow
Water dropping around (or over) the filter sock area
The baffle to the return pump

Few things here:

Initially sounded like a loud, flushing toilet
Getting the water line in the overflow that you see below absolved all of that noise
Pre-ReefMat I have these pads (also below) covering the filter sock holes. I also have some ceramic bio media in the two cups before the sock holes.

I can pretty easily get to silence at this point in the flow.

Then I just have the water level in the return chamber at a spot where the moment it starts getting to an audible level, the flow over the baffle, the ATO kicks in and fills it up quickly.

A near perfect fit with these:

Overflow water level:

Two of the three offending spots below. Note the water in the return chamber is a bit on the high side. If you're going to setup AWC, dear god whatever you do don't touch ANYTHING unless you'd like to see how fun things get when multitasking leads to one of the two pumps shutting off far early. So. Many. Swears.

blaxsun · Apr 12, 2022

Just a bit on the high side, lol (at first I couldn't figure out where the return chamber was!) In my overflow I have the water right at the edge of the emergency overflow. I run my ATO over the return/filter sock chambers which leaves me room in the upper left to mount the UV.

frank-lloyd-reefer · Apr 12, 2022

Lighting. After a lot of internal debate, and my mind changed multiple times, I went with three Neptune Sky lights w/Ecotech mounts. I really, really like how configurable they are. I have very little experience with SPS corals, but I'm hoping I can dive into that challenge this time around. We'll see how that goes with these:

blaxsun · Apr 12, 2022

The SKY would've been in the running if it was available at the time I got my Radions. You'll have to let us know how you like them (3 should give you excellent coverage).

frank-lloyd-reefer · Apr 12, 2022

blaxsun said:
Just a bit on the high side, lol (at first I couldn't figure out where the return chamber was!) In my overflow I have the water right at the edge of the emergency overflow. I run my ATO over the return/filter sock chambers which leaves me room in the upper left to mount the UV.

Which UV do you have? Yep upper left was my first thought but last time I measured the size of the protein skimmer made that impossible. Moral of the story: always be measuring.

I was pretty sure I wouldn't be down with dealing with those filter socks. It was an accurate prediction. Were the ReefMat not coming out I'd be trying to figure out how to DIY a ClariSea into that part of the sump. Since I'd probably screw that up I'm waiting for the ReefMat to drop.

blaxsun · Apr 12, 2022

bbobek said:
Which UV do you have? Yep upper left was my first thought but last time I measured the size of the protein skimmer made that impossible. Moral of the story: always be measuring.

I was pretty sure I wouldn't be down with dealing with those filter socks. It was an accurate prediction. Were the ReefMat not coming out I'd be trying to figure out how to DIY a ClariSea into that part of the sump. Since I'd probably screw that up I'm waiting for the ReefMat to drop.

I run an AquaUV 57-watt powered by a Sicce SDC 7 pump. I ran it along the back (sideways) above the skimmer chamber. My sump isn't all the way back, so I have about 6-8" space to play with.

I'm on the fence with the ReefMat. I don't like the idea of having to permanently alter my overflow piping and I hate the idea of two wasted chambers (since I dose into one of them and it works really well). But we'll see. I have room to run a modified variant on the alternate (non filter sock removal) option.

Simon_M · May 5, 2022

i follow this thread (posts) with great interest. I “ordered” a REEFER XXL 625 last weekend, with the order being confirmed on Tuesday and with delivery early next week. Stocks of the XxL 625 didn’t quite materialise because Red Sea is switching over to the 625 G2. The confirmed Tank is the 625 G2.

Between ordering and getting a Tank delivery “in motion”, I had plenty of time to consider if I had made the right choice. I have access to all the Red Sea manuals, drawings and other RS info. There is also a great many threads discussing Red Sea Tanks, the cabinets and any potential issues with gaps appearing between the Tank and the top of the cabinet e.g. observed with the “paper test”.

I observed that the range of Tanks that would fit in my Sitting Room have changed over time. RS have made changes which improve the product and seek to minimise the amount of issues (reducing their costs) until what we now have. My selection considered the overall size: 425, 525 or 750 Tank widths and the available space (long wall, divided in half with a fireplace and with existing furniture on the non Tank side). Whilst I could fit any of the widths, I settled on the 525 Tank length but ordered the 625 for the additional width and height. But, not before having downloaded all the manuals, drawings and figuring out what has changed and the differences.

Although I convinced myself that the XXL 625 was the right Tank, I have ended up with buying the 625 G2. In the UK the prices for the G2 increased by a small amount and the XXL (R3, G1) reduced. The G1 to G2 changes didn’t justify the price difference (for me) and RS listed differences which apply across the board but which were (mostly) already in place on larger versions.

525, 625 and 750 Tanks and cabinets are mostly more similar than different between G1 (aka R3) and G2. Like all companies, RS change their products based upon issues but only make changes where the additional costs are justified. These changes show up as obviouse things Tanks (dual outlets, 2 return pipes, diaphragm valves) etc. but also subtle (but sometimes important) changes.

The most significant change on 525 was the addition of a brace in the middle of the 525 cabinet on the G2 version. Any issues found with early 750 and bigger Tanks required RS to add a metal brace in the middle of the sump compartment so that the Tank cabinet has support spanning the front over middle of the Sump and the dividing wall between Sump and the Chiller cabinet. The 525 has same capacity but width heights were altered (slightly).

The drawings for the 525 R3 show a revised Sump layout but without a brace or a “brace kit”. The 525 G2 has a brace over the middle of the Sump. For all the parts of the cabinet all the P/N are unchanged except for the brace and the front kick board being black/white rather than a black and white separate version. This surprised me because if it is deemed necessary to add the brace on G2 then what about existing customers of R3, G1 Tanks. It may be that the change in width/height cause the change to be implemented and not because of Tank sagging (returns etc.).

The 750 Tank and Cabinet are similar except a brace lit was offered to 750 owners and became standard with the 750 R3 version. The G2 version continues with the metal brace. Looking back, you do wonder how a Cabinet could be designed with only the Sump/Chiller divider providing support at the front?

Similarly, the XXL 625 had a brace kit that became standard on the 625 R3 and this is carried over to the G2. Only the kick board being black and white vs a separate black and white versions changed. I think RS packages the doors/sides with the Tank and the cabinet is boxed separately so that the same Cabinet can be provided for both black and white versions?

The R3 changes is mostly about improvements in the Sump layouts. The XXL Sump (I was most interested in) has the “same layout” and siize as the newer G2. What changed, was not having a fixed section for the Socks and the removal of the front slot so that the dividing wall no longer has two positions. On the RHS there is no glass wall for the RHS slot. I look at these changes as being for the benefit of RS e.g. as a cost reduction. Similarly for the 525 and 750 R3 Sumps.

Red Sea make a “big thing“ out of the change to a removable Sock area so that a ReefMat can easily be installed. It is certainly true that (for me) the idea of having to cut way the silicone and remove glass on the. XXL 625 R3 so that the ReefMat can be fitted. Especially as I have seen (and like) the ReefMat in my LFS.

I didn’t like the idea of cutting a new Tank, especially as this becomes a “one way street”. Cut the Sump and you cannot revert to using Socks again. Sell the Tank and the ReefMat is no longer an option. Even so I still preferred the cost saving of the older XXL 625 R3. Because…

Regardless of choosing the RS ReefMat or Clarisea (or similar) the cut away of the R3 Sumps isn’t required and the benefit (to me) don’t justify making the change. With the 625 G2 that I have ordered, I do have the “benefit” of the plug n play Socks removal and so the older XXL 625 R3 has (for me) no real disadvantage. Because…

Red Sea provide a Product FAQ for the ReefMat that show how it can be added to existing R3 Sumps (or earlier versions). The same layouts should also apply to G2 Tanks (same size and layouts).This also applies to most of the bigger Tanks including 525 and 750. Why ignore the benefits of the G2? Because…

Without a Protein Skimmer and ReefMat, the R3 Sumps have the RS Reservoir initially over the Sock are and close to the pipework/valve. Adding a ReefMat means either cutting out the existing Sock Dividers (or removing it if it is G2). Another option is simply to position it to the left of the sock area. If it replaces the Sock location, then it also sticks up above the Socks area and the RS Reservoir has to be moved (or removed).

If you are using the ReefMat (or similar), then you had to move the RS Reservoir. More than likely, you will use a Protein Skimmer. Adding the Protein Skimmer requires that the RS Reservoir is removed if it was already moved to the LHS. Removal of the RS Reservoir means that you also have to find a new location and Red Sea didn’t provide a shelf/supports in the Chiller compartment. If it is placed on the base of the Chiller Cabinet then an pumped OTA is needed (and worst case case a barrel outside the Cabinet is required).

The Red Sea Hardware ReefMat FAQ provides two options for most Red Sea Tanks including 625 but also 525 and 750. Option 1 requires removal of the Socks Compartment and giving up the RS Reservoir that sits above it after installing the ReefMat and where a Skimmer is also in the Sump.

Option 2 is the most interesting (and for me beneficial) choice. It doesn’t require cutting the Socks area (on pre G2 Tank) and it accommodates the ReefMat, Skimmer and Reservoir. There is a small area that s a “dead space on pre G2 Tanks, but the advantage overwhelmingly trumps the disadvantage of either cutting the Socks area or going without the RS Reservoir, IMHO. The common layout of R3 Sumps should mean that the same Option 2 can be used for my own 625 G2 Tank.

FWIW, the Red Sea configuration wizard suggests an RSK-900 and ReefMat 1200. The layout shows the RS Reservoir removed. Only when you look at the FAQ, do you see the option of keeping all three components. I opted for the 600 skimmer for the size of tank and the ReefMat 500 because these are big units and Sump space is at a premium. The combined “working” width of 600 skimmer and ReefMat 500 is 12cm (5”) narrower than the RS suggestions. Overall the revised layout in the G2 versions doesn’t (to me) justify the extra cost. That said, I’m trying to justify the additional expense incurred and the best thing (so far) appears to be better circulation with dual return outlets.

blaxsun · May 5, 2022

G2 = Dual outlets, thicker glass, corner reinforcements, aluminum brace, precision valve, removable media tray/panel, ReefMat ready (no pipe cutting), red piping, metric or imperial bulkhead adapters (separate).

Simon_M · May 5, 2022

The glass thickness on larger tanks hasn’t changed. The Dual Outlet is better, but Dealers provide (at cost) the Red Sea Y Outlet Splitter, so that the flow can be directed to both front corners with flow in from the middle (so either shouldn't have too many dead spots). The bracing was already standard on XXL 625 or larger Tanks. The pipework is standard metric (32mm) sizes (may be thinner wall construction).

In the announcement Videos, some (subtle) details of Tank construction may not have been emphasised e.g. the inside on the verticals or across the inside of the front edge? Either version of the 625 has 15mm base but with 19mm on the front and sides. I have yet to see if that difference is visible and so it will be interesting when the 625 G2 arrives next week...

There was no mention of a change to the Tank construction. Are the corners now reinforced on the inside with a plastic fillet (triangle) of hard plastic (sometimes referred to as Armor)? Or were the existing R3 versions already starting to be supplied with this version (especially the front/base edge e.g. if the bottom is thinner glass e.g. 12/15mm or 15/19mm on some Tanks). Cleaning glass with a scraper presents difficulties if the silicone isn’t to be damaged - is that why the corners changed?

FWIW, I am looking forward to receiving the 625 next week. Where possible, I have RS Products because (to me) they seem to be well designed and a good match, so RS Lights, Skimmer, Wave 45 (2x) and ReefMat. Other choices are available, but I opted for the "simple" Red Sea Tank, with RS Products and using (carried over from my earlier Tank) RS Salt, RS Foundation, RS NoPoX, RS Trace, RS Reef Recipe etc., if the LFS had RS (branded) coffee, fish and corals I would have looked at them...