Progress journal FW refugium system

[Luananeko]

Disclaimer: This was more of an experiment/fun project to get used to sump/refugium systems more than something that was really needed, so yes, I fully realize how overkill this system is

I have a 20 gallon long that I've been using as an actinic/glowfish tank for a while now. While I absolutely love the tank, I hate how live plants ruin the look, and I've been too spoiled with my heavily planted 75 gallon tank to go back to not using live plants on a tank... Also, the tank itself was standing on a bookshelf that was just a touch too short in length, so I wanted something with better dimensions to properly support the tank. Add in the fact that none of my LFS have stands that match my decor for a 20 gallon long, and I was pretty much looking at either living with how things were or build my own solution.

I started off with simple goals...
1) I wanted to see how a sump/refugium system worked so I have an idea of what works when I eventually have a saltwater tank.
2) I needed somewhere to put the live plants so I still got their benefits without taking away from the actinic/florescent look. I always have extra plant trimmings from my 75 gallon tank, so this would also give me a spot to let those smaller trimmings grow out to the size my LFS prefers to buy.
3) I wanted extra water capacity since the tank is fairly heavily stocked and I wanted some buffer in case life caused me to miss one of my weekly 50% water changes.
At the time I was planning this out, Petco was having their $1 per gallon aquarium sale... I was originally planning on a simple 5 gallon sump, but found out on arriving at Petco that their sale didn't apply to the small tanks, only 10 gallon tanks and up. For the price of one 5 gallon I could get 2 ten gallon tanks, and at this point I had the crazy idea that part of the sump could be a shrimp breeding tank for fun. So now I needed to build a stand to hold the display tank, as well as two 10 gallon tanks...

First issue... I've never built furniture before, let alone furniture sturdy/strong enough to support an aquarium's weight. After much research and several tweaks, I sort of landed on the following design...

Top level would be the 20g long display tank, middle level 10g would be a shrimp tank, bottom 10g would be my main live plants area for growing out extra trimmings from my 75 gallon tank.

The entire stand would be made out of poplar plywood (ended up going with 3/4" thick instead of 1/2" thick due to availability and extra strength), while the middle shelf is supported by three 1"x4" support struts (on in the middle of each side, and one in the center of the back pane. I considered adding steel brackets for extra strength, but was talked out of it as it being way overkill for the planned weight The bottom shelf would rest on 1"x2" trim pieces both front and back length-wise, both to look nice as well as to give added support. At this point I also found some intriguing article about lava rock serving a de-nitrification purpose for FW tanks, so I decided to experiment with that in the shrimp tank area since I know shrimp like really low nitrates... Ideally I would like to keep the nitrates low without needing weekly 50% water changes (like I do now) and/or without having to understock the system, so the lava rock and live plants combo will be a good test before I think of adding the shrimp (aiming for 6 months from now, pending how fast the lava rock bacteria matures).

So I got all the lumber, had the Home Depot folks cut it to my carefully calculated sizes and brought it all home just to find out they hadn't cut very carefully... The back pane was a full half inch long, among other issues. Trekked back to Home Depot with lines showing where things SHOULD be cut and had them fix it. Spent an entire day assembling, and it turned out great!
(ignore the demon kitty eyes, only had my cell camera handy when they decided to claim the stand as their own)

Went through the VERY messy step of staining the wood to match the rest of my decor as well as water proof it, and started putting in the tanks and wiring! I was leaving for a trip the following day, so I apologize for the lack of pics of this step... I went with Eshopps overflow boxes for going between the display tank to the shrimp tank, and from there to the plant grow out tank. Turns out that starting the U tube siphon in the overflow boxes is MUCH trickier than I realized, and several small floods resulted while attempting to start both overflows. The waterproofing step I did earlier held up though!

Unfortunately I couldn't get the system working before I had to leave, as I forgot to plan on how to keep the tubes from the overflows to their next tanks above the water line to avoid creating a siphon... So today I started working on it again! Made a lot of good progress...

To be continued later, as it's getting late!

 

[Luananeko]

Yesterday I attached the plant lighting to the two sections of the stand, as well as set up the power plugs... The plugs hang from the top to help minimize electrical issues if any splashes/floods occur.

Here's the full shot of the stained and water sealed stand with the display tank and in-progress shrimp tank moved into it:

Ignore the display tank's layout, I was in the middle of cleaning up a food mess caused by my husband feeding the wrong pellets while I was gone last week

Close up of the initial hardscape of the shrimp tank, mesh bag in back is mature media from my 75 gallon to help start seeding the lava rock with bacteria:

I've since filled the shrimp tank, put in a temporary circulating pump to keep good oxygenation, and planted my initial plants (minus the moss that will be on the rocks). I forgot to grab a pic though, so I'll do that tonight once the water clears.

The bottom grow-out tank is in the middle of having a divider glued in to separate the plants from the return pump, hence why it's not shown in the full stand shot. Sadly my first stab at siliconing the divider in place had some leaks... So I'm letting it dry today before I patch the holes and try another test. I'll post more pics later!

 

[jtez]

Love the idea of this, keen to see how it works out! What plants are you keeping in the refugium?

 

[Luananeko]

Thanks! The actual grow-out section of the refugium will have whatever mish-mash of plants I've trimmed from my 75 gallon tank that need to get bigger before my LFS will take them, so could be anything from the following list:
Limnophila Aromatica
Sunset Hygro
Green Hygro
Red Cabomba
Amazon Sword (my big one is constantly throwing babies and my LFS wants them 4"-6" tall first)
Rotala Indica
Ludwiga Repens x Arcuata
Ludwiga Ovalis

Ideally I'll aim to keep the faster growing ones in the grow out tank as much as possible, since that will give the best nitrate reduction effects

Here's the updated pic of the shrimp tank section so far:

The two front corners have Lidernia sp. India, Green Cabomba is in the back, and my army of baby Red Tiger Lotus plants that I'm trying to grow bigger before taking them to my LFS are in front The dangling cord is for the temporary circulation pump and will go away once I turn on the full system.

 

[Luananeko]

Okay... 4 attempts later at siliconing in a divider for between the grow-out plant section and my return pump, and the seal is FINALLY water tight...

I've also tweaked the sections of my tubing where the overflow boxes drop down into the next tank so I have a place to break the siphon when the power goes out... I basically added a T connector right at the surface level. Unfortunately, I realized after putting it in that this just makes the water go out BOTH exits of the T rather than just letting air in the top exit

I've since added plugs on the middle T exit for each of the two sump tanks with two small drilled holes each. This provides enough resistance that the water is going out the end left open, but still allows the siphon to break when I turn the power off.

Initial trimmings added to the grow-out tank, as well as 3 river stones I'll be trying to grow algae on as a treat for my otos and shrimp:

I've now got all the pieces hooked up and working like they should, but unfortunately the system is EXTREMELY noisy, so I don't have it all running yet. It seems like the problem is with how the Eshopps overflow boxes are designed. I'm getting an open drain/gurgling type sound out of them. I was hoping the plugs I added to the drop into the sump tanks would solve this, but from my reading it sounds like I need a Stockman drainpipe or a GurgleBuster to fix it. Once I make a few of those I should be able to leave things running!

 

[Wy Renegade]

Interesting design/set-up. Following along to see how things turn out.

 

[Luananeko]

Sorry for the lack of updates, life's been a little chaotic lately and I've been sick the last week to boot. The sump system has been running for around 3 weeks now with no disasters! Also, I've been unable to do any water changes since I started running it (not on purpose, just been so freaking busy and sick). Normally I do 50% water change weekly on this tank, otherwise the nitrates get way too high very quickly for my Amano shrimp due to a combination of few live plants plus decent stocking levels. I tested nitrates today to see how things were doing and was pleasantly surprised to see it at only 40! Granted, it's effectively had double the water volume for the last 3 weeks, but even so, the extra plant capacity and lava rock have definitely had an impact! I've also had to do frequent water level top offs since this system has a very high evaporation rate, so there's been frequent infusions of trace nutrients from fresh water. I'm extremely pleased with how this mad science experiment is turning out so far The last 3 weeks have allowed a wonderful level of biofilm and algae to develop in the refugium tanks, so I should be able to add my first shrimp for the shrimp colony pretty soon! I just want to keep monitoring the nitrate levels a bit longer now that I have time to get back on a normal water change schedule

 

[Luananeko]

Update! I added a few more fish to the display tank around the 4th since I now have the extra water capacity to work with, and saw the expected jump in nitrates while the bio-filter adjusted to the new loads. It's been 2.5 weeks since the added fish, and the nitrates seem to be getting eaten up quite nicely! Just shy of a week since the last WC and I'm only sitting at somewhere between 10-20ppm Nitrates Not bad considering immediately after the new additions the nitrates were jumping up to 100+ at the end of a week!

Again, hard to say whether the live plants or the lava rocks are the deciding factor in the denitrification, but I'm leaning toward thinking the primary source is the lava rocks since I really don't have that many plants between the two refugiums. Also, the plants grow much slower in my refugiums than they do in my 75 gallon tank due to that tank getting higher light, higher temperatures, and more ferts, so I can't imagine they'd be sucking up quite so many nitrates compared to what the plants in my 75 gallon do. In light of that, I can only conclude that the lava rocks do indeed work to harbor the anaerobic bacteria necessary for denitrification, much like live rock does in saltwater systems! Very happy with this finding

 

[1998golfer]

Update! I added a few more fish to the display tank around the 4th since I now have the extra water capacity to work with, and saw the expected jump in nitrates while the bio-filter adjusted to the new loads. It's been 2.5 weeks since the added fish, and the nitrates seem to be getting eaten up quite nicely! Just shy of a week since the last WC and I'm only sitting at somewhere between 10-20ppm Nitrates Not bad considering immediately after the new additions the nitrates were jumping up to 100+ at the end of a week!

Again, hard to say whether the live plants or the lava rocks are the deciding factor in the denitrification, but I'm leaning toward thinking the primary source is the lava rocks since I really don't have that many plants between the two refugiums. Also, the plants grow much slower in my refugiums than they do in my 75 gallon tank due to that tank getting higher light, higher temperatures, and more ferts, so I can't imagine they'd be sucking up quite so many nitrates compared to what the plants in my 75 gallon do. In light of that, I can only conclude that the lava rocks do indeed work to harbor the anaerobic bacteria necessary for denitrification, much like live rock does in saltwater systems! Very happy with this finding

That's very cool...Will have to consider some lava rock in my sump now
Anyways thanks for telling us about all that you've been doing here...
-1998golfer