My Biocube 29g build project

  • #1
Hello all!

I've lurked this forum for years, I had a 60 gallon freshwater tank for six years and read a lot of great info off of this forum. As I started out I also befriended some LFS employees that helped my wife and I a ton as we initially setup our aquarium, also through these same LFS folks information we got wasn't so good and caused us some serious downstream problems. But after moving, selling the 60 gallontank and busy with young kids for four years. I'm ready to start my tank adventure all over again!

I'm hoping posting my adventures and failures are not only entertaining to read but people following in my path, or crossing it, find it as good of a source of information as I've found on this forum already. I'll include prices but if people want sources feel free to PM me as some forums don't like that, which I understand. I'm a research nut by trade and it bleeds over into my hobbies. Some of the pictures I post people might see things that interest them, feel free to ask as I'm happy to share all the knowledge I have, some things I've done for decades others not so much. Like keeping a freshwater aquarium, so much has changed in the past four years from what I knew that it's been great to read up all over again.

I began new aquarium journey looking for a biocube because I like the sump idea behind the main display area, long as the tank isn't leaking the chances of failure are really low. Spending 450ish for a 29 gallon tank and stand is laughable, plus my wife wouldn't like it very much, so I started lurking Craigslist for a bargain. The one's I came across were in various states of dry dock or marine function. Some of them pristine condition and others a dumpster fire, I always check dates of postings or multiple posts to see how long somebody has been sitting on their item they are trying to exchange for cash. The best deals I've found usually comes down to me being more patient than the seller.

The pristine aquarium owners all laughed at my 100 dollar offerings as they would only take top dollar of what they paid for their stuff, I have no problem putting in some elbow grease to clean up a diamond in the rough, but it never hurts to ask! The one I eventually bought the seller didn't respond for three weeks, really nice guy and he let go the tank and stand for 125. The stand was in relatively good shape but the tank was not and I broke down the dead marine situation in the guys living room while he watched TV in his bedroom. Since I was going with freshwater I didn't want to take his protein skimmer which was full of nightmares so I told him I was putting it into h is kitchen sink to which he waved from the chair in hid bedroom and said 'drive safe' and then I left. I locked the guys door for him as I walked out so nobody robbed him while he was glued to his TV.

125 got me a biocube 29, stand, heater, new pump in box, various pristine cleaning tools suspiciously never looking to be ever used, old pump chewed on by cat I just dumped.

More to come

  • #2
Wow, great so far! Looking forward to more!!!


  • Thread Starter
  • #3
When I got the tank home and into some proper light I realized what a mess it really was. I took some pictures to show what I started with but our camera memory card had an accident with some magnetic embroidery hoops in my shop and I erased them all on accident, d'oh!

The back was covered in thick coraline algae, there were huge blooms of it on the sides where the substrate wasn't. when I removed the bioballs from the back a lot of them were stuck together with what looked like calcium worm deposits that wove in and around almost all of them. They went from the tank right into the garbage.

After I had all the loose material removed and the leftover sand washed out, I filled a 5 gallon bucket with 2 gallon of vinegar and 2 gallon of water and everything I wanted to save went into the solution. I tried scraping a bit of the algae from the tank but it wasn't going anywhere so I filled a plastic bin with straight vinegar after cleaning out a local grocery store of the cheapest gallon jugs they had and let the tank sit on its back with vinegar covering up to the black back plastic.I didn't start to see results for two days.

Wish I had pics of before and after, the after pics was a great transformation. Anyway, moving on.

While the tank was in detox I bought some biohome minI and biomotion and some filtration sponges for mechanical filtration.
  • #4
Welcome to the forum . Congrats on the new tank. Looking forward to future posts....Alison
  • Thread Starter
  • #5
Tank cleaned, and washed out all of the vinegar.

I started measuring the sump area and how I wanted to

Hit the local Ace Hardware and had them cut some Plexiglas for me for a rough 8" by 4" by 3.5" box that would hold the 1kg of Biohome media, there are many different ways to do a volume measuring I just went down and dirty with the bag the stuff came in and gently sorted it into a box shape and measured it to get a general idea of how it would condense down. I was able to get it down to a rough 6" square without breaking anything inside the bag. After clanking around with a ruler in the sump I got my basic size. I used some heavy card stock to then do something like this
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I trimmed the paper down small enough to get it into and out of the tank without issues but kept it large enough so it caught 90% of the water traveling through the sump. Then I knew what the Plexiglas had to be trimmed down to.

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Thanks to
for the quick and clean way to blast through Plexiglas without cracking or shattering a cut, I always keep my old oscillating blades for drywall cutting because they always seem to work, now I have two reasons. Only downside is the massive amount of Plexiglas melted shards from cutting, it gets everywhere...
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Measure twice cut once! Or glue twice if you let it get that far
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For those geometrically challenged here is what easily fits inside


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  • Thread Starter
  • #6
While my box was drying I started messing with the filters you're supposed to buy at 10 bucks for two that will last a month. The seller had two, one in the tank and one in a bag in the stand, I assume he never bought new filters. Some incredible upkeep costs on filters alone, so...

I gutted it and drilled holes in the bottom of the filter and using two scrap pieces of Plexiglas made a reusable filter, I did two pieces so the filter would sit flush against the tank but
gave me the idea to use Plexiglass to start with.
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A great example of not measuring is when I take my newly modified filter base and try and place it into the tank, turns out these are not even the right filters!
So I went out and cut some egg-crate and went to town making a coarse first stage filter, none of this is glued or zip-tied together to make changing the filter that much easier. I cut the filter about an inch longer then I needed and wrapped the end around the bottom. I'll use rubber bands or something else when I do filter changes in the future, probably might double up the filter to make this a little better fit.
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I really like the moving bed filters, sand filters or K1 or hexagon filter media whatever you can get your hands on, they seem to really have low maintenance, really high filter volume. Plus they just look cool IMO. Since I plan on doing a shrimp breeding tank, cannot have enough filtration especially since this stuff works so well from what I've been reading. I wanted to do a non-air stone mixer to reduce the C02 loss so I bought a lower flow pump and got a piece of plastic to fit into the out flow and then put the pump inside the bottom of my sump. Since there was no cheap priced 45 degree angled plastic piece I figured I'd buy a hose barb and just heat it up and bend it in place, easy peasy!


Vie de Chef torches, great for finishing Sous Vide steaks, not so good at heating plastic to make it bendable, in fact it makes it a complete disaster! I tried multiple ways to heat the plastic, slowly, and make it bendable but mostly I just made a mess.
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It is bent, kind of, so instead of putting this where I had planned I just put this where the water exits the sump and hope the deflection is enough to stir the Biomotion moving towards the drain. Time will tell.

Time was ripe to add media to baskets and sumps so I was excited to actually get going! I can't help but see old dried dog turds when I look at this Biohome stuff, I hope I'm not alone! If it does its job I honestly don't care what it looks like.

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Good enough for government work, the bottom I went and bought a 15 dollar piece of egg-crate from a big box store, I looked at different cost effective things to build out the rest of my tank and there really is nothing I could find that will work as good. Cheap, doesn't leak things into water that we know of, structurally sound, incredibly easy to cut and shape, water flows through it easily with no modifications. I love it.

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I'm such a spazz though that I was a little upset my box has a lot more space then I expected at the top, I even went back through my notes to make sure I wasn't so far off I missed a number somewhere. But when I went to take the betta from his cycled tank and put him into this tank after it cycled for two weeks with the bacteria balls. I realized I had put some media from the bag after I did my measurements

Regardless, super happy fish in super clean water! I waited until I saw Nitrates appear in my testing before I added my betta, keeping track with a log to determine when Nitrates start to drop just from the filtration alone. Really excited about that!
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Starting the hood revamp and light adding soon as UPS delivers my new soldering station. Hoping the plant can hang on for a few more days!
  • #7
Good gracious you've been busy. He looks happy. You're posts gave me a good laugh though. That is why I don't go the DYI route. Alison.
  • Thread Starter
  • #8
Alison, sometimes I don't know why I do DIY builds...

So I've got a friend who does some really inspiring work over at Slothfurnace, I like to pester the poor guy about LED lights for Halloween costumes, kitchen lighting projects and aquarium light building now. If you really want to see some amazing DIY builds, check out the master. He really helped me out with some Ohms Law questions I had and kept me from burning my aquarium down, ha ha.

For my light build I wanted to go with 6500k LED lights as they seemed to be the sweet spot for freshwater plant growing and they look the most appealing for displaying your tank, I also added some 430nm blue LEDs and some 650nm red. I bought a couple 2.5" by 15" blank aluminum heat-sinks for about 3 bucks a piece(10 with shipping), a 60w 12v LED driver for 20 bucks, 10 6500k 1k lumen chip lights for 10 bucks, 10 red lights for also about 10 dollars.

After gutting the existing Biocube hood and removing all unnecessary parts I had plenty of room for the heat-sinks and enough room for airflow to keep them cool, I measure everything and start drilling and soldering.
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When I do a test and fire this light up, none of the pictures turned out good, the heat coming off of this was intense. Way more then I expected a LED light to heat up with, I put it on the heat-sink and go grab a drink and when I come back the light is at 130 degrees and the heat-sink is nearing 90 with just one light. Trying to cool the aluminum off with a desk fan for a few minutes, it still barely put a dent in the heat this wiz bang light was producing. I had switched the fans in the hood with some larger slower RPM fans and sitting the fan on top of the heat-sink couldn't bring the temp down to an acceptable level. Into the future project box they went and back to the drawing board...

I had thought about using strip lights a few months ago but I didn't think they would produce the intensity I needed, out of options and wanting to wrap this project up I bought some 6500 to 7k strip lights off Amazon. A shipping snafu later Amazon gifted these to my project for nothing, can't go wrong with Amazon Prime folks!

Adding the dot lights, cleaning up the install and finishing with some heatshrinked ends.
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Tied the red LEDs into the Biocube power supply, wanted to use these for sunrise and sunset. Strip lights arrived and I snatched them away from the delivery person, my wife, and scurried back to my garage to continue work. When I fired up the strip lights I wasn't overwhelmed with their brightness, will have to see how well they grow plants and go from there, I expect I'll be back outside with this aquarium hood in the near future...
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Too many projects man, unfinished projects atop ongoing projects, never seems to end
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So here is no hood or lights
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Dawn and Dusk
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Fullspectrum with fish Cardinal Tetras and Orange Flash Cacatuoides
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After we got the Orange Flash home my wife noticed he had a wound on his side, the LFS is really great and they ended up giving us some medicine to dose the tank with and I bought some Kanaplex. I had hoped to plant and setup my newly arrived UV but looks like I'll have to wait a week or so.

I'm incredibly happy to have a tank setup again and everything is functioning great, really hate when a fish gets hurt though, checking the water parameters it is all in perfect shape so it shouldn't take long to get this guy healed up.

Would be great to get some input from folks, my next phase is planting and getting some plants established then I can start to populate with my shrimp!


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