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Sub-gallon stacking system .123G PICO


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Hey everyone! I used to keep track of my projects on other forums years in the past; I figured I should try to document my tangents once again.


I found there are several usb powered miniature water pumps on the internet and it squeezed my thoughts into reason of a similar ratio... put a mini-pump in a mini-sump for a mini-reef!


So my latest experiment is a very tiny pico reef aquarium; the system is constructed from found up-cycled material and attempted-budget-purchased equipment. I plan to play with it while I setup other more sustainable systems. The tedious DIY aspects of it are complete; its success will depend on equipment application/reliability from this point. The empty "display tank" can hold .123 gallons. The system is very nearly sealed using multiple containers and a mini pump for movement, no airline or stone. My goal is to culture some type of really-small-polyp coral and micro-fauna. Obviously a few or more concerns: can the pump produce sufficient movement? Avoiding the inevitability of rapid temperature and PH fluctuations. Also, choosing the appropriate species of coral...


I just filled it with saltwater not even a few days ago; I had been taking checkpoint pictures and hand-recording processes and will share them with details here as soon as I can.


- Brant


Here's a teaser photo for now:



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Thanks guys


@Frag Factory I plan on running the refugium/middle section's light at opposite times as the display. I left room behind the middle section for a JBJ Nano Glo fixture - it's a tad over my budget for algae growth on this scale; however, it's dimensions fit the jars quite ironically, and since the system can be rapidly disassembled for maintenance, mounting it by magnet seems appropriate. I am concerned of its general potential, but I can always re-purpose that, too - planning on ordering it soon. The bottom section will not be directly lit, but will likely have ambient light from above; this section will be for equipment only - pump, heater and top-off float valve.


While we're on the topic, this is the finished bottom compartment. This jar's outside dimensions depict an approximate .34 gallon volume including the glass. With some drilling, it fits a 10W Aqueon mini heater, THIS pump, and a modded float valve.




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This is going to be very interesting for sure. If the JBJ light is out of your budget,check out RapidLed they have a moonlight driver that can drive 3-4 leds @ 350mah and you can get leds from them too,or get a 3up from StevesLeds. 

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@Reefkid88 Thank you - those are good fallback options - I have a dual gooseneck Rozway lamp laying around with 5 diode led plant grow bulbs in it; I was thinking of using that if I need to as well.



Moving on up:


The middle/refugium section is where water from the display will drain into. This jar is nearly identical to the sump jar; so, another .34 gallons on the total system volume. The bottom jar's lid is fixed to the bottom of the middle jar with silicone on the sides and also in the center holes.


Choice modified glass containers act as an overflow and adapters for water redirection. A cut and heat manipulated pop-top container sits in slits engraved in a mini glass jar extending off the bottom of the overflow hole - this moves water away from the pump's intake - the refugium section sits flat when removed from the system with this piece set aside.


The pump supply line from the sump is built to insert into the pass-through tube (API test tube) in the refugium section from the underside via a system formed from 1/4" line, a modified 3/8" quick-connect plug, a rubber washer and a diy neoprene foam gasket. Above the pass-through tube, I made a glass washer for the 1/4" supply line, sealed everything up with silicone, and topped it with identical transition materials used for the sump supply line in preparation to transfer the supply to the display.


I forced a hollowed clear cover of a tiny spray bottle with a snug O ring into the mouth of the overflow/bottle to raise the water level in the middle chamber and prevent siphoning through all the small parts' crevices. The bottle neck's cap holds this seal very well in place. (It is important not to let too much water drain to the lower sump in the event of power loss because the equipment cord hole is not 100% sealed and placed as high up as possible)


A cut pop-top container and a diy neoprene gasket fits over the bottle neck and is also held in place with the bottle's lid to restrict light going into the overflow. I drilled a UV proof container's plastic cap to fit over the bottle's cap to allow the UV proof container to be modified to dissuade algae from clogging stuff up; wrap the dissuader with nylon mesh ribbon, affix container lid, pop onto overflow (easily cleanable). To redirect the water overflowing from the display, I stole the lid from the goldfish food (added a little hole to vent air accumulation).











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 I could never do anything this cool,I would destroy 100 containers to get one to look halfway decent lol. 


 What are the stocking plans with this ? 

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@Reefkid88 :wink:I went through a few myself, luckily nothing glass. I have been holding onto reusable materials for a while for diy purposes, so I had options and replacements nearby; but I appreciate the compliment. I'm not entirely sure of the stocking plans; Zoas, GSP, montipora, other slow encrusting types? Burrowing brittle stars? I don't really think a single shrimp, crab or snail would be okay in the display. I already ordered some chaeto, but might try other species later on.



After the complete system's construction, I had the system running with plain water to test for leaks before adding any debris - disassembled and altered 3 or 4 features to address 2 leaks. The next step for this section was large/medium/small particle sand mix and rock rubble towards the front of the fuge.




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So the display is THIS acrylic container made by Boxbox. I already had one from who knows where, but I cracked the bottom when tightening the 3/8" bulkhead that is supposed to hold it to the fuge lid. since then, cork has been implemented under the display around the bulkhead to support the pressure. The original Boxbox container that I had laying around fit so perfectly on top of the jars that it was one of the reasons I started the pico, though seemingly necessary, I really wasn't looking forward to settling for another container. My girlfriend took time to find new ones on the internet - almost drilled the brand off the bottom, too.


The overflow is a pop-top container upside down with a hole in the lid for the bulkhead. I melted slits + three deep ones all around the bottom of the container.


The supply line T's so that I can do water changes without opening things up. The upper-most valve allows air into the drain line for evacuating held-up water after use. The supply line spirals to hold on to a UV proof bottle that I will be using for a RO DI resevoir. The fuge lid also has plug access drilled for a temperature sensor (cord holes are fitted with rubber grommets and neoprene plugs).


The hardscape is removable if I pull 1/4" bulkhead and supply nozzle out of the way - I thought this would be useful for maintenance. It was constructed using mounting epoxy.


The outside dimensions of this container depict a .123 gallon volume. That's a total available volume of a little over 3/4 of a gallon.


Time to put sand in and set it up. (FYI - that's 50 ml saltwater and cultured sand from a cycling bucket in the display)










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This is the setup with the RO DI reservoir in place -  the res lid has a diy debris filter made from filter floss and pop-top lid for the pressure relief hole to keep stuff out and minimize evaporation. Quick connect for accessibility.




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I kept track of the amount of water it took to fill the system. There is already 50 mL in the display - topping off through the float brought the system's actual volume to ~1250 mL.


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Salinity 1.0248 using reef crystals. Waiting a while to test nitrites. Currently monitoring the temperature - running the pump and fans without any light or heater - the room temp around the system is 75 to 80F - the system has been staying at the same max temps, 78 to 80F. I will likely be lowering the room temp just a little in the near future.

If this hardscape doesn't work out, I can remove the hardscape altogether and go with a more open layout in the display.

Coral thoughts?

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I was suggested mojanos as a potential inhabitant; a really unique idea, but I am wondering if one or two could clog stuff up (3/8" overflow from display) - and I came across graceful anenomes as an option, but I am definitely worried about their size. I thought about doing something that encrusts. Montipora a bit much? Just zoas? I originally wanted to do a a few ricordea, but after the hardscape happened, I think even one would look too slammed in. This thing really only has 1/4" - 7/8" space between the rock and the acrylic. If I end up removing the hardscape, I do think I will make room for one or two ricordea within the new one.


The Bayite temperature controller is working well, but it seems to read and adjust temperature at .2 degree intervals as opposed to .1; I don't think this should be a problem for the price, but will be watching. Temp is holding at 77.5-77.9 w/o lights.


I'm also going to try putting an inline usb voltage meter before the pump so that hopefully I can see if the pump is having issues before it fails (I have a couple stored for spares).

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This is nuts... in all the best ways!


Also, I have had that temp controller for about a year and a half and have been really happy with it so far.

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@Porkpie5000 Thanks! Good to know - it's been doing just fine so far, this system will definitely test it with it's potentially quick fluctuations.


The chaeto came in the mail a couple days ago; I decided to try seeing what a water change would be like before putting any in. The diversion line  can pump out 325 mL before the pump runs dry - that's 26% of the system's actual volume; I think that is a decent amount for weekly or so changes. Since the drain line is 1/4", it holds excess system water after closing it off; the flush option came in handy, I just inject RO DI after use to keep it clean.



Then I added ~325 mL conditioned saltwater from the top and plugged the pump back in - note the flow.



After checking the salinity after the wc, apparently I was short saltwater volume, and the res auto-filled with freshwater; the salinity after was down to 1.022 g/cm3. To adjust, first guessing, I added 1 gram of salt mix to the display, waited, and took a reading with about a .0005 g/cm3 increase - awesome - added 4.5 more grams, waited, took reading: 1.0245 g/cm3 and time to add the chaeto. Turn off pump, remove display, 2 tsp algae!







I am working on something to reduce the flow in the display a little because the water from the pump touches the lid and a plethora of salt is creeping out; if I rotate the supply nozzle in the display, the pump has enough power to dig in the sand. I have something in mind...will update with pics of the modification when finished.

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The flow in the display has been much better; it doesn't touch the lid anymore. I finished the modification to decrease the velocity a couple days ago.



The modification is simply a T off of the supply line to some type of chamber that I haven’t entirely decided what to do with yet.





The original plan was a calcium reactor. After the attempt to keep this thing compact was achieved, I became concerned that this size of a calcium reactor might decrease the system’s pH in the end. I still might try to do it though. It is placed so that water from the pump will flow down through potential media in the test tube while a line near the bottom of the device can dose CO2 (or liquid? if not a cal reactor).

On a side note, I adjusted the pico's temperature range to be more relaxed. I allowed the system to run without its temperature control to see where it would fluctuate to with room temperature control under normal operation. After finding the higher, lower and average values, I set the pico’s temperature controller to the average and am allowing the temperature to fluctuate almost to its threshold before the controller implements a control device. The allowed fluctuation is now 3°F under, 4°F over. Since adjusting the controller and with my room cooler’s wireless thermostat placed next to the pico, the temperature controller has barely had to do any work.

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This is just tooo cool! My head can't even wrap my head around it lol...


Encusting... maybe Cryphastrea coral? Comes in many colors and compact. 

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Cryphastrea - very nice suggestion @Tamberav - definitely will be keeping in mind



I wanted to take the time to update the journal with a these few processes:

I have been using Microbe-lift Special Blend since start-up

(also had used it in a led lit bucket of water w/sand and rock I had set up prior to pre-cycle some aspects for this thing - water, sand, pods).

I have added Special Blend each time after four 25% water changes so far.

I had added one pellet of food to the system each time I added Special Blend.

I introduced five amphipods and one additional tsp of chaeto to the fuge yesterday.

First reading tonight: ammonia just over .25, no readable nitrite, nitrate at 5.

The entire system (pump, lights, temp control) is running off of an APC back-UPS for a home network/pico aquarium.

Here's a shot of that madness:


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  • 2 weeks later...

System update before I forget what's happened:


I set the cooling fans aside because they never come on, but I set the high temp alarm at a lower tolerance on the controller so I can monitor it more  closely. I've still been using a goose-neck lamp and small grow led for the refugium; will be until other projects let off required funding.



Oct 28 After noticing brown algae starting to accumulate in the display, I added one dwarf (or tiny) cerith snail to the display. Also introduced one blue-leg hermit crab to the refugium. I was relatively confident that this thing cycled already (start-up: Oct 12) being that it is ~1250 mL volume. I found out that the diversion line from the pump (made for water changes) is clearly awesome for drip acclimation.


I have been working on adding a second chamber to the "calcium reactor". 1st attempt I broke the 1st chamber's test tube, remade everything. 2nd attempt sprung a leak, which was kind of a big deal; luckily I caught it before the salinity was greatly affected. I disassembled the system, rinsed the outside of each section, reassembled and remade the faulty rubber insert. It's running with the additional chamber now; it's still in testing and still in test tubes.


Nov 1: More brown algae in the display. Since the hermit and dwarf cerith were still doing well, I went out for another dwarf cerith, but couldn't find one. I did introduce one nassarius snail to the refugium and one burrowing brittle star to the display, though. I was thinking that something should be photosynthesizing in the display to start competing with algae at this point; @TamberavI want to try cryphastrea or maybe montipora when I have a better influence on most elemental parameters. For now, I decided to try something "tolerant" - found a 2 polyp frag of rasta zoas that seemed appropriate as the guinea pig. Dipped with diluted H202, placed in display:



Everything is still well today - watching the zoas closely; they were fine day 1, but have been temperamental since day 2 - skirts usually only peaking out. It could be that I haven't really fed the system in a while, so I'm going to try that today. It may be light intensity. It may be the change in light cycle... this pico's light cycle is unique to this system. I have been theorizing one of the reasons that micro volume aquariums (especially reef) are difficult to make low maintenance and near self sustained/contained because of the attempt to keep them in tune to acquainted circadian rhythms, which on these scales should probably be much different. With the fuge and display lights alternating the standard 12 hours each, I was concerned about the fluctuation potential of the pH in this volume because there might be a high capability for organisms to excrete or consume a plethora of elements in too little of an area given too ample of a time period. My theory is that by limiting the amount of time that all organisms are subjected to photosynthetic light, I may be able to avoid this threshold accumulation. So, the pico circadian rhythm is like this: light over display from 1-5:15am, 9am-1:15pm, 5-9:15pm ~ light behind refugium from 5-8:20am, 1-4:20am, 9pm-12:20am. Fifteen minute wake up period for the chaeto, a shorter cycle for the it to keep over-consumption (competition for nutrients) less likely, and a short all-lights-off period because the algae will finish off its photosynthetic exhaustion for a little while after light isn't present. There's a display/fuge lighting overlap for extended coral photosynthesis, plus this thing looks good with both lights on lol. Trying not too move the zoas, just going to see if they adjust in 2 weeks or so.

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  • 2 weeks later...

Quick updates:

The pump ceased - switched to the spare and need to apparently buy another; hoping one lasts somewhere more sufficient.

Bought a teeny tiny blue hammer frag; introduced to display - seems to be doing okay, pic soon. Planning to move it to larger system when ready.

Burrowing brittle star died - watching parameters, nothing seems abnormal.

Display led failed - ran it with cfl 4 days - purchased this and put it over the system tonight

Finished upgrades to the calcium reactor; there was a persistent slow leak that, in the end, required sealant - now waiting on the media.


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