My 8L (2G) pico tank

immortaly007

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In the last few months, after keeping freshwater shrimp for years, I've started my saltwater journey in a challenging way by trying to run a pico tank. Since I'm pretty new to reefkeeping, I am interested in your feedback. I also thought this might be interesting for future reefers to read.

In November 2024, I visited Vivarium, a large aquarium conference in the Netherlands, and found a "good" deal on a used Aqua Medic Armatus XS. In the end, maybe I should have gone with a new one: it turned out the tank was missing some pieces, notably the holds for the lamp and the cover for the overflow, and the display tank is pretty scratched from (probably) too rough cleaning. But I figured, let's see how it goes.
So, I went to the LFS, got some Red Sea Coral Pro Salt, live rock, and a replacement accessories pack (30 nov 2024). For the sump, apart from the filtration media that came with the tank, I added some bio balls, active coal, and more live rock.
IMG20241130122359.jpg
IMG20241130121953.jpg

This led to a nice algae bloom, pictured here after ~2 weeks on Dec 11:
IMG20241211224818.jpg


So far so good, time to cycle! I realized I didn't like the supplied lamp since there was no way to automate the lighting schedule (other than on/off on a timer). I ended up upgrading to an Aqua Knight V2 on a black friday deal, which I quite like.

As time went on, algae and small organisms started coming on the live rock. On Jan 19th, I spotted some starfish-looking little critters (some type of Asterina). I am also spotting more an more feather dusters in various colors (white, red and brown feathers). I think they're cute, so I am keeping them (macro picture with a zoom lens of the star fish):
IMG20250119213044.jpg


I also ordered some test kits so I could check on parameters, specifically
* Red Sea Reef Foundation Pro for Ca, Mg and KH
* Hanna PO4 ultra low range tester
* Salifert NO2 and NH3/NH4 tests
* Nyos Nitrate

This showed that Magnesium was pretty high (around 1600 between januari and march), while KH was low: around 6 when I first measured it. I brought i back up to ~9 with water changes, but it keeps dropping a little daily.

But, since I now kept it in an "acceptable range", I decided to add the first corals: two Zoa frags on Feb 8 (pic the day after, on the first day, they were closed)
IMG20250209110201.jpg
IMG20250209115452.jpg


I also got some color-filter phone lens a few days later, which led to these pictures. All the white dots I think are Spirorbid Worms:

IMG20250212205158.jpg


The green Zoa (bottom in this pic) seems to be more picky. It opens slower, not all polyps open every day. I figured maybe I wants to be closer to the center of the light, so I moved it there. I seems to help a bit.


On Feb 22, after the Zoa's had been doing well for a few weeks, I decided to add, what I thought, was GSP (see this topic). It turned out to be a green hairy mushroom (rhodactys) species. It looks cool tho, so I'm keeping it. I did move it down to the floor later, as it would regularly (almost) topple over:
IMG20250224164956.jpg
IMG20250224123630.jpg


Mar 15: The mushroom is doing well, so I decided to add the GSP that I wanted to add originally. My plan is to eventually have GSP and the mushroom cover the original live rock (and zoa's cover the rocks on the left). I also added some snails. I think they are a Trochus histrio and Turbo fluctuosus, to help take care of the algae.
IMG20250317182130(1).jpg
IMG20250316103252.jpg
IMG20250316212228.jpg


Currently, as you can see on the last picture with the snail, the green zoa has been unhappy since the new additions (and also in the morning). It has just been closed. I have noticed that it's generally the most happy right after a water change, and then throughout the week gets less happy until I do another water change. I do pretty large water changes (~40%) weekly, to keep the parameters as close as possible to "freshly mixed" water. I am not sure if this is maybe annoying the Zoa's.
Also, nutrients are very low, I'm consistently measuring Nitrates 0-0.5 and Phosphates 0-0.03. With KH also slowly dropping throughout the week and boosting again at the water change.

Some Armatus XS tips:
Last weekend, the pump completely stopped working. It turned out that you can open it up with sharp nails or a screwdriver, and clean the tiny sponge and filter mechanism.
I created a custom ATO for the tank using a ESP8266 (Arduino board), an external water level sensor, and a small USB pump. A normal ATO didn't fit in the tank. Let me know if you're interested in pics/build info on that.

I've now pointed a camera at the tank to try and do a timelapse to see if I can find anything that might be causing the zoa's to close, or if there's times when they do open.

In the future, I might add some sexy shrimp, but first I want the corals to be happy, as I'm concerned that sexy's would eat zoa's if they're unhealthy.

Parameters:
Temp: 25C
NH3: 0
NO2: 0
NO3: 0
SG: 1.025 (usually I am for 1.026, don't know why it dropped)
KH: 7.5
Ca: 410
Mg: 1360
PO4: 0

Any tips on how to keep the zoa's happier, what to test for, or tips on the scape, algae control, or coral selection, are very welcome!
 
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bubbgee

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Flow can affect zoas.. too much can irritate them to close. Too much light can also cause that problem. Look for pods or asterina that can be irritating them as well.
 
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immortaly007

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The Asterina's (I have 2 of them that I know of) are currently riding the new Trochus snail (shell). I hope he doesn't mind. The flow is low where the zoa's are, and the light I think is not too bright (I have the Aqua Knight set to 30% for the blue channels at max brightness). But it is hard to know for sure without a PAR meter. The zoa's are at least not stretching, but I'm not sure how to recognize if they're burning?

I am suspecting low nutrient levels and have been dosing some Red Sea Reef Energy AB+, but so far that doesn't seem to do much.

Another option is that the mushroom is blasting some kind of chemical into the water which is blown onto the zoa's.
 
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immortaly007

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I've created a time-lapse of yesterday (every second is 2 hours). I mostly did it to check if there are any signs of life in the "green zoa" (the second from the left). You can indeed see it sort of "breathing", but it's not happy. Around the 10-second mark, I am feeding the corals with AB+, and the mushroom closes in response but quickly opens up again after.

I've ordered an Iodine test kit, and will continue to observe over the next days to see how it goes. I read that people had zoa's randomly close for a week and then open up again. But seeing how both zoa colonies seem pretty unhappy, there must be something that they don't like.

The GSP (behind the rock in the time-lapse...) and Mushroom seem happy, tho.
 

Gumbies R Us

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In the last few months, after keeping freshwater shrimp for years, I've started my saltwater journey in a challenging way by trying to run a pico tank. Since I'm pretty new to reefkeeping, I am interested in your feedback. I also thought this might be interesting for future reefers to read.

In November 2024, I visited Vivarium, a large aquarium conference in the Netherlands, and found a "good" deal on a used Aqua Medic Armatus XS. In the end, maybe I should have gone with a new one: it turned out the tank was missing some pieces, notably the holds for the lamp and the cover for the overflow, and the display tank is pretty scratched from (probably) too rough cleaning. But I figured, let's see how it goes.
So, I went to the LFS, got some Red Sea Coral Pro Salt, live rock, and a replacement accessories pack (30 nov 2024). For the sump, apart from the filtration media that came with the tank, I added some bio balls, active coal, and more live rock.
IMG20241130122359.jpg
IMG20241130121953.jpg

This led to a nice algae bloom, pictured here after ~2 weeks on Dec 11:
IMG20241211224818.jpg


So far so good, time to cycle! I realized I didn't like the supplied lamp since there was no way to automate the lighting schedule (other than on/off on a timer). I ended up upgrading to an Aqua Knight V2 on a black friday deal, which I quite like.

As time went on, algae and small organisms started coming on the live rock. On Jan 19th, I spotted some starfish-looking little critters (some type of Asterina). I am also spotting more an more feather dusters in various colors (white, red and brown feathers). I think they're cute, so I am keeping them (macro picture with a zoom lens of the star fish):
IMG20250119213044.jpg


I also ordered some test kits so I could check on parameters, specifically
* Red Sea Reef Foundation Pro for Ca, Mg and KH
* Hanna PO4 ultra low range tester
* Salifert NO2 and NH3/NH4 tests
* Nyos Nitrate

This showed that Magnesium was pretty high (around 1600 between januari and march), while KH was low: around 6 when I first measured it. I brought i back up to ~9 with water changes, but it keeps dropping a little daily.

But, since I now kept it in an "acceptable range", I decided to add the first corals: two Zoa frags on Feb 8 (pic the day after, on the first day, they were closed)
IMG20250209110201.jpg
IMG20250209115452.jpg


I also got some color-filter phone lens a few days later, which led to these pictures. All the white dots I think are Spirorbid Worms:

IMG20250212205158.jpg


The green Zoa (bottom in this pic) seems to be more picky. It opens slower, not all polyps open every day. I figured maybe I wants to be closer to the center of the light, so I moved it there. I seems to help a bit.


On Feb 22, after the Zoa's had been doing well for a few weeks, I decided to add, what I thought, was GSP (see this topic). It turned out to be a green hairy mushroom (rhodactys) species. It looks cool tho, so I'm keeping it. I did move it down to the floor later, as it would regularly (almost) topple over:
IMG20250224164956.jpg
IMG20250224123630.jpg


Mar 15: The mushroom is doing well, so I decided to add the GSP that I wanted to add originally. My plan is to eventually have GSP and the mushroom cover the original live rock (and zoa's cover the rocks on the left). I also added some snails. I think they are a Trochus histrio and Turbo fluctuosus, to help take care of the algae.
IMG20250317182130(1).jpg
IMG20250316103252.jpg
IMG20250316212228.jpg


Currently, as you can see on the last picture with the snail, the green zoa has been unhappy since the new additions (and also in the morning). It has just been closed. I have noticed that it's generally the most happy right after a water change, and then throughout the week gets less happy until I do another water change. I do pretty large water changes (~40%) weekly, to keep the parameters as close as possible to "freshly mixed" water. I am not sure if this is maybe annoying the Zoa's.
Also, nutrients are very low, I'm consistently measuring Nitrates 0-0.5 and Phosphates 0-0.03. With KH also slowly dropping throughout the week and boosting again at the water change.

Some Armatus XS tips:
Last weekend, the pump completely stopped working. It turned out that you can open it up with sharp nails or a screwdriver, and clean the tiny sponge and filter mechanism.
I created a custom ATO for the tank using a ESP8266 (Arduino board), an external water level sensor, and a small USB pump. A normal ATO didn't fit in the tank. Let me know if you're interested in pics/build info on that.

I've now pointed a camera at the tank to try and do a timelapse to see if I can find anything that might be causing the zoa's to close, or if there's times when they do open.

In the future, I might add some sexy shrimp, but first I want the corals to be happy, as I'm concerned that sexy's would eat zoa's if they're unhealthy.

Parameters:
Temp: 25C
NH3: 0
NO2: 0
NO3: 0
SG: 1.025 (usually I am for 1.026, don't know why it dropped)
KH: 7.5
Ca: 410
Mg: 1360
PO4: 0

Any tips on how to keep the zoa's happier, what to test for, or tips on the scape, algae control, or coral selection, are very welcome!
Hopefully the gsp doesn't overtake your pico tank, haha. Following along though!
 

Tahoe61

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Cool Pico.
To add more flow consider adding a Mightyjet Mini gph 266 with a controller. You can dial it way down. If it doesn't fit there are more options.
All For Reef works well for me to maintain the water chemistry in my Pico.
Don't be afraid to use a tooth brush to clean algae.
 

p1u5h13r4m24

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First of all welcome the forum and the hobby! As I’m sure you already know smaller lower volume tanks are much harder to successfully keep corals in. However with the corals you have in there you should be able to maintain chemistry with small weekly water changes. Keep the water changes small so you don’t accidentally start your cycle over. Don’t let the success of this discourage you from keeping a reef. Plan where you are putting your next larger reef tank!
 
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immortaly007

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Thanks for your responses!

Have you seen MK_REEFS gsp nano tank? Makes me want to build one too.
I'm assuming this one? It looks awesome indeed! I'm hoping my "rock" will look a bit like the bottom left one in that tank.

Cool Pico.
To add more flow consider adding a Mightyjet Mini gph 266 with a controller. You can dial it way down. If it doesn't fit there are more options.
All For Reef works well for me to maintain the water chemistry in my Pico.
Don't be afraid to use a tooth brush to clean algae.
I read that zoa's like low flow (as long as they're kept clean), or do you suggest adding more flow around them?

First of all welcome the forum and the hobby! As I’m sure you already know smaller lower volume tanks are much harder to successfully keep corals in. However with the corals you have in there you should be able to maintain chemistry with small weekly water changes. Keep the water changes small so you don’t accidentally start your cycle over. Don’t let the success of this discourage you from keeping a reef. Plan where you are putting your next larger reef tank!
That is an interesting idea. I have currently been doing rather large water changes weekly. Maybe I should switch to a 10% (~1L) a day-ish regime, instead of 3-4L in the weekend to keep it more stable.
 

Tahoe61

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I would say moderate flow. Increased flow helps with algae growth. I dose NeoNitro, Microbactor7 and AFR to a 6 gallon. Moderate lighting for my Zoanthids as well.
 

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Thanks for your responses!


I'm assuming this one? It looks awesome indeed! I'm hoping my "rock" will look a bit like the bottom left one in that tank.


I read that zoa's like low flow (as long as they're kept clean), or do you suggest adding more flow around them?


That is an interesting idea. I have currently been doing rather large water changes weekly. Maybe I should switch to a 10% (~1L) a day-ish regime, instead of 3-4L in the weekend to keep it more stable.
Actually, this one:

 

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My Zoes/shrooms/GSP/ Cloves/Acans, like around 10 Nitrates and .05 - .1 Phosphates. I dose daily to keep these numbers up. If your Zoes have algae on them, you might want to dip in some peroxide at 80% tank water - 20%
(3%) peroxide.
 
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immortaly007

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I definitely need more nutrients. I think I prefer dosing nutrients to running a super-low nutrient system. So I will look into that!

Regarding algae on the zoa's: I think it is mostly around the polyps themselves, but I could try a peroxide dip. How long should they dip?
 

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Sorry about that. 2-3 minutes should be good.
As for dosing. You can make your own if you can get Ammonium Bicarbonate and Sodium Phosphate Dibasic in your country. Very cheap way to go. I can give you the formulas that I use if needed.
 
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immortaly007

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Small update: the past few days I have been dosing some NO3+ and PO4+ (from DSR, which I think is a local (Dutch) brand). And the green Zoa has finally been slightly opening up again. It's not fully open yet, but at least it gives me some confidence that lack of nutrients is probably (one of) the reason(s) they were closed.

I'm gonna keep up dosing the recommended amount, which is daily 0.15ml/100L for NO3+ and 0.2ml/100L for PO4+. To dose correctly, I diluted the solution 1/20. I will also measure at least weekly to keep everything in check.
 
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immortaly007

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Another quick update.

The tank is in a pretty rough shape algae-wise. This has a couple of reasons:
  1. I haven't cleaned the overflow, as I thought it would maybe look cool/natural if it's full of algae, and would provide food for the snails.
  2. I have been dosing nutrients (NO3 and PO4).
  3. I expected that the snails would at some point go and eat all the algae

Since the weekend, the Trochus hadn't moved. First I thought he's just taking a few days off, but then last Wednesday the GSP, who is usually very open, was completely closed the whole day. I thought maybe he, like the snail, was just shocked because I accidentally forgot to turn on the ATO after a water change the day before, so salinity was probably slightly elevated.

However, after correcting that, yesterday he was still closed the whole day. And the Trochus still hadn't moved. So I was getting worried. Yesterday, I picked up the Trochus, and he didn't seem to respond at all. But he also didn't smell as bad as I've previously had snails smell. I did do a big (2L/30%-ish) water change just to be sure, didn't have time to measure all parameters, but they were fine in the weekend.

This morning, I decided to put the snail in this floating cup so that if he's dead, he won't further pollute the water.

I would really appreciate some help regarding:
  1. How should I handle the Trochus snail? Is there a way to check if he's really dead? What could have caused it? Starvation because he doesn't like these types of algae?
  2. What should be my next step to fix the algae problem?


IMG20250425101708.jpg


The GSP last weekend:
IMG20250419150306.jpg


The GSP this morning (yesterday was pretty much the same)
IMG20250425101720.jpg
 

bubbgee

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Yeah. Might have starved. I usually feed algae pellets if I notice that the tank doesn’t have algae just in case for the grazers. I don’t keep a trochus anymore and switched to a diamond goby.

That algae looks like dinos but I can’t confirm. But it looks like snot. Does it have bubbles? If so it’s not algae at all and the inverts are going to be miserable.
 

Tahoe61

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Complete water change and scrub. I would probably do a water change multiple days in a row.
 

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