Journal of a 60g shallow reef and aquaman cave

[ChloroPhil]

I put both pumps on Reef Crest Random at 100% and am letting them sit for 24 hours to see what sort of substrate displacement I get. Here's where they're placed, if you can tell through all the crap they kicked up. The substrate was smooth before I turned them on.

Front of the tank-

Right side-

Left side-

I'm having a hard time believing that anything's actually settling in this thing with those two beasts running! Both rear corners have thin layers of settled debris. I'm going run the sump return through a 1" SCWD with an outlet in each rear corner. Hopefully that'll help keep things suspended.

Reef and planted tank progress shot. I'd just finished siliconing black painted styro panels to the back of the plant tank. They're for attaching epiphytes to for an additional layer of depth.

 

[scolley]

Phil - that just looks like sand that was not washed before being put in the tank. If so, a big water change should go a long way.

Also, IMO fine sand with MP40's on a shallow tank is asking for trouble anyway. Why not try some course aragonite instead? I doubt it will blow around.

 

[ChloroPhil]

Steve,

That's exactly what it is. Nasty, gunky, dirty, old sand that is destined for the sump/remote DSB. I want to try my hand at growing seagrasses and such in there. I had two reasons for putting it in the tank: 1) I wasn't sure how stable the rock would be without substrate and I didn't want it blowing over with the pumps going full bore; and 2) I was curious to see how the fine grained texture would be affected with the pumps going all out.

Sadly, the bulkhead on the left has a pinhole leak so everything's got to come out of the tank tonight anyway for resealing tomorrow. Once the silicone's cured I'll be putting the rock in there to get soaking again while I figure out the mix of grain sizes I want to use. I want to keep the grains as fine as is practical simply because I don't like the look of larger grained particles. That's why I did the flow test. After putting that other rock in there things have stayed in place much better. In fact, I had to run home to grab something during lunch, checked the tank out, and didn't seen any major displacement since setting the pumps last night. While 100% sugar sand won't jive, I'm fairly confident 1-2mm grains mixed with larger and smaller stuff will work nicely.

 

[ChloroPhil]

9.20 update-

After 24 hrs of the pumps going 100% on Reef Crest here's what I saw when the tank was drained. To be honest, I sort of expected there to be more displacement in general, but without the localized intensity. It was a worthy experiment as it shows me that I need to move the right side pump a bit higher and where I need to put some extra rock to buffer currents. Seeing the locations of super-fine particle (silt and clay size, in geotechnical terms) deposition also tells me a lot about localized currents and where I need to keep an eye out for potential nutrient rich zones in the substrate.

And yes, Steve, I need use larger grained substrate. I never doubted your suggestion. I'm just a curious person and wanted to see what happened with this stuff while I could. This little experiment fell into the "why the heck not?" category. May as well do it while I had the chance and it would't hurt anything.

The big surprise to me was how much flow there was between the rock groups. I expected that to be the low-flow zone rather than the rear corners. It was quite a pleasant surprise, to be honest. I feel comfortable putting just about anything in that area and knowing it'll get hit with a good current.

Sadly, even the 2mm< sized grains got shoved around quite a bit. I think 75-80% is going to have to be the max I run the pumps on. Here's to hoping that's enough to encourage the sort of growth habits I want.

On with the pics. Don't mind the big mound on the left side. I made that so I could get the siphon to the glass. That area was fairly undisturbed from what little I could see beforehand.

 

[scolley]

Well, you've figured out what the limits were. Good to know. I assume one pump was anti-synched to another?

Seeing that simple one-vortech-on-each-side configuration, makes me sorry that Reef Crest is not MORE dynamic than it is. I've got similar placement, on Reef Crest most of the time, and anti-sync just is not as dynamic as I'd like. When one side goes up to full power (or close) you would expect the opposite side to dwindle to nothing (or nearly nothing). But what I find on my little tank (only 24" wide) is that there is still pretty heavy blow to any coral anywhere near the low-powered pump. If the difference between the high-powered and lower-powered pumps were higher, Reef Crest might actually simulate the back-and-forth flow of a real reef crest. But from what I can tell, that never really happens. Anything close to a pump is always getting blow from the direction of that closer pump.

Would love to have seen what your test did to the sand if you had a true alternation like that... blowing hard from one side, then the other. Would be interesting.

 

[ChloroPhil]

Steve,

No, the pumps weren't synched at all. They were just going at whatever random intensity their algorithm had them going at, independently of each other. I'm going to be sending EcoTech a box with all the parts I've found to see what we can do about getting everything up to snuff and into the current generation. I've gathered the systems are at least 5 years old from the serial numbers. It may be time for an upgrade, if the price is right.

After this test I think my goal is to have them synched so one's on Reef Crest and the other is on Lagoon and vice versa. Like you said, Reef Crest just isn't as dynamic as it could be, and if Lagoon pushes more water than Reef Crest, then it seems like a good combination. One side will move the water while the other gives the higher magnitude random pulses, and vice versa. I think coming up with the combination of settings and timing I want will take quite a bit of tweaking. I know I can get more flow than I want out of these guys. The trick now is going to be dialing in the settings to provide the magnitude of variability in conjunction with amount of water moved that I'm looking for. That actually sounds like a lot of fun.

Talking with Jon over at EcoTech it sounds like the Short Pulse or Long Pulse settings are intended to create waves/back and forth movement more than Reef Crest is. You might try anti-synching on Short Pulse to see what you get.

 

[scolley]

Thanks Phil. I don't want to take this OT. But if you have a professional relationship with Echotech, you might be able to get more info than I have in threads in their forum. I've played extensively with ALL their modes. And it appears to be pretty clear that Echotech pumps - in their vendor supplied modes - can only do pulses of motion that are all in the same direction. They cannot create true back-and-forth motion (water flowing one way, then reversing) as found on a reef crest. Not out of the box anyway...

 

[ChloroPhil]

Yeah, they need to make them capable of going in reverse, or at least shutting completely off when in synch/anti-synch modes. In fact, that's why I originally thought of putting them on timers rather than trying to synch them.

Don't worry about being OT. (Almost) Everything's on topic in this thread.

 

[scolley]

Well, clearly you get the problem. I bring it up only because of the nature of the tank you are trying to build. Would be really nice to see that back-and-forth in your tank.

 

[ChloroPhil]

Yeah, it would. I saw a video of a tank where someone had created a gyre wave that looked pretty intense. It scared the hell out of me though thinking about all that pressure on the seams. It's cool to see, but there's no way I'd risk the integrity of my tank just to create a wave. If I were keeping LPS and Softies it would end up looking really dramatic, no doubt. As it is, with mostly SPS and few fish, I'm not sure a wave-type flow pattern would really show that well. I've got a feeling this is going to be a visually static setup. No shimmer and mostly sticks and plates. They're going to be big fat, strong, sticks and plates though!

The best solution for this tank is probably going to end up being a simulation of the crazy random flow during the change of tides during lights-on and then gentle lagoon flow during lights-out.

 

[scolley]

Caution is a good thing when dealing with seams, says the guy that's seen 75g rapidly discharge onto his floor.

Vortech's have their NTM (Nutrient Transport Mode) that's worth looking at IMO. It does a good job of kicking up detritus into the water column, so it can be carried to the sump for removal later. But it goes into a pretty powerful burst mode as a part of the process, that MUST put some stress on seams. A good bit - I'd wager - if you are running MP40s in a modest sized tank. I run it for 30 minutes daily, but I've only got MP10's.

 

[ChloroPhil]

I think NTM just might blow the water out of my tank. Reef Crest came pretty close when I put a pump close to the surface. It's worth a try though. :spin2:

 

[scolley]

If the funds become available, a Neptune Apex with a WXM module (additional cost), you can control how long a given Vortech mode runs, and at the intensity you desire.

Just like every thing else in this hobby - all it takes is money.

 

[ChloroPhil]

Right now that's a lot more money than I want to invest. Perhaps in the future. Ok, more than perhaps..quite likely. I want to take care of all the necessary stuff first though..like corals, lighting, and filtration options.