13 Aug 2019
I have been sitting on the fence about switching one of my planted tank to a Marine Reef Tank for a very long time.
And I have finally decided to take the plunge after doing close to 6 months of background studies and look up on Marine Reef Tank.
A lot of Planted Tank folks, like me, are “afraid” to touch the reef tank. And vice versa, a lot of Reef guys are “reluctant” to try on a Planted Tank. I believe the reasons are all the same, the methodology is almost complete opposite.
Moreover, we always heard that the cost for a reef tank is astronomical. Which I found out, is only true, after a lot of reading and researching, when you are going fully “automatic” and you wanted to grow next to impossible corals. If you just want a reef tank with some corals, a couple of nemo, and a small team of clean up crew in a nano reef tank, the cost is still manageable, provided you know what to buy/use.
So my journey begins and I want to share with you the process. I also have a secondary objective, that is, to minimise my transitional cost. Hopefully, through my experiences, they can benefit you greatly.
So What Can be Re-Used?
So here I have, a 24 gallon 45cm x 45cm x 45cm low iron cube tank (classified as a nano tank in reef tank!), a Fluval 206 canister filter, a high pressure DIY CO2 canister tank, a Chihiros A series light, a small circulation pump rated at 300L/h, a small air pump, Tropica substrate, some rocks and drift woods.
Well, none! ?
The tank is 6mm thick rimless. Most people will recommend at least 8mm. But I’m gonna risk it because this tank is quite well built and is of a reputable brand and it is only 2 years old. And the final decision was it is a cube tank as such the pressure on the bow is not as high as a rectangular tank.
Most marine tank comes with drilled holes or a wet sump. If you are going to re-use a tank without a wet sump or drilled holes you will have to get an overflow box. Since we are trying to minimise cost and re-use whatever we have on hand, I am not going to get a new tank just for that. I am also not going to risk drilling holes on my tank.
I was very close to buying a overflow box with a sump tank, but after several calculations, the cost is way above my intended budget.
To give you a perspective, an overflow box will cost you USD200 easily, and that’s just the average quality.
Next a sump tank will cost you another USD100, less protein skimmer, pumping and plumbing. An in sump protein skimmer cost USD100 upwards for entry level.
And plumbing… That is my number one worry actually instead of cost.
In a canister filter, the system is a closed loop. Water gets syphon into the canister by gravity and pump out via a pump. Never gets spilled.
You buy it off the shelve at Walmart during Black Friday Sales at 70% off retail price, bring it home, put your old bio media in and add the new ones that comes with it, put your purigen in, install the sponges, close the cover, fix the tubing that comes with it, prime it, plug it power, and tada! Sit back and relax. Job well done!
But a sump, it is a completely different experience. A very hideous experience altogether.
First a sump tank cannot be bought off the shelve and does not come with all the parts that are required to make it work. No no no. It is just the beginning of your nightmare. First you will need to determine how much space you have underneath your display tank. You need to consider space for your pipings, space for a protein skimmer, space for a refugium (a what?), space for return pump, height, width, depth. Dafug.
Then you need to measure the piping length you will need, the number of connectors you will need. All sold separately.
And if your tank have no overflow built in you will need an overflow box, also sold separately, and without instructions on how to get all those things together.
And I just read that the overflow box is a ticking time bomb waiting to fail. And when it indeed fail you will end up with more freshwater in the tank and killing everything in it.
The Sump System
In a sump, water gets overflowed into the overflow box, down into the sump by gravity, travelled through the sump, and reach a pump. This pump will then pump water back into the display tank. Sounds simple and logical, but it is not.
First, getting the correct rated flow is paramount. If your pump pumps too fast and you will have a low level sump, not good. Next if your pump is slower, you risk a overflow sump.
Second, the number of pipings that one requires is mind boggling. There will be connectors along the way from the overflow box to the return pipe. One after the overflow box. Two just before the outlet into the sump if you are forming a simple L outlet, three connectors if it is a S shaped outlet into the sock. One after the pump. Two more at the return to the display tank if it is a L shape, Three if it is a S shape.
So 6 connectors for a minimal plumbing setup, each with its own chances of failure. And any failure will result in water on your carpet or floor. The amount of stress one has when going to sleep is unbelievable! I’m not gonna succumb to that.
But is there any other way?
After doing some searching I am going to do something that will be deemed inelegant. I will use a overhead sump tank. ? I don’t see people doing it but I will try. More on it later on when the overhead sump tank arrives.
So why can’t we use back our ever trusty canister filter?
Canister – The Nitrate Factory
The first thing that struck me was that our all time favourite canister filter is a “No-Go” in marine tank. What?! It is the devil! Noobs started with it. But in the box that comes with the canister it stated for Fresh and Salt water aquarium, no?
Canister filters are considered “Nitrate Factory” in the other camp. We Planted Tank folks have the luxury of not worrying about Nitrate in our tank because we have our plants to absorb all those nitrate. In fact Nitrate is free ferts to a certain extend. However, in a marine tank, in the absence of all those nitrate hungry plants to take in all those excess nitrate converted by the bacteria it will become toxic for the inhabitants and creates all sorts of problems.
And so the de facto standard for filtration IS a sump tank.
On the other hand, in a Planted Tank, the sump tank is a NO GO as your CO2 will be lost and the canister is the ultimate de facto standard for filtration. You can go on weeks without cleaning the canister.
Nevertheless, you can still use a canister filter for your marine tank, just that you will need to perform weekly maintenance on it so that it will not become a nitrate factory. WTF? Yes, weekly cleaning of a canister filter. I know, that defeats the purpose of having a canister filter (from the point of view of a Planted Tank person).
Now, back to sump tank. Why a sump tank is preferred for a marine tank is because you can quickly perform cleaning of your mechanical filtration media is a blink. In sump tank, you can see how filthy your sponges/floss/sock is and do a quick change.
Also, in a sump tank you can house your heater and protein skimmer, and a refugium. A re-fu-WHAT? Think of it as an algae pool. It is basically an area where you actually grow algae, macroalgae, and copepods. Within this refugium is another eco system whereby the algaes and copepods grow without the risk of being eaten. So when they thrive, they will absorb the evil nitrate from the tank. Furthermore, due to the high O2 nature of a sump, nitrate consuming anaerobic bacteria which thrives under high O2 environment can flourish. These nitrate consuming anaerobic bacteria cannot live within a canister because of the close-loop nature of a canister which will deprive them of O2. (Now you know why a canister is frown upon).
In marine tank, the bio media is replaced by live rocks. Think of it as a huge bio media ring. They have the same functions. However, you need to buy them “live” as opposed to buying them dry and cultivating them from scratch.
My research points me to the fact that certain beneficial “life forms” cannot be cultivated from those “dead” dry rocks. So if you are starting from scratch with 100% dry rocks, you may have problems later on due to the absence of those beneficial “life forms” whatever they are (I’m still learning!).
So, you have no use for your bio media.
Next, you must be thinking I am sure I can use back the LED lighting for your Planted Tank. WRONG!
The spectrum is not the same! ??♂️
Yes you can grow corals but Planted Tank lights are more towards yellow and orange side of the spectrum while the marine and reef tanks are more towards the blue end of the spectrum. Your tank will look funny with Planted Tank lights.
But I found out Chihiros make reef lights at prices similar to those for Plants. Phew!
Well, my 300L/h circulating pump will not work. In reef tank, I see people recommending 300gph wave maker for a 10g tank ? And recommendation of 20-30 times the tank volume for return pump!
That’s a tsunami for a Planted Tank!
Well, after further readings and understanding, it seems that in the absence of a canister filled with heaps of bio-media, the marine tank relies heavily on live rocks to perform the bio filtering of the water. And in order to have optimal filtration, you need to push water through these live rocks.
Furthermore, any debris and poop will have no chance of staying and will be swept up by the current and eventually picked up by the sump tank.