Schmidt Aquatics
New Member
Hey everyone,
I’m finally getting into the saltwater world again! Two weeks ago, my Fluval Flex 123 (32.5g) reef got delivered. Had some trouble with getting the stand delivered, as the postal service had trouble transporting it, but now I finally got it.
For everyone else considering a Flex 32.5g, I want to list my key learning points so far, and my journey. This way, I can share all the filtered information i’ve gathered about this tank from forums, Facebook groups and Reddit.
I purchased a few pieces of gear and bits to optimize the system:
- An extra Fluval 3.0 Marine LED 75cm which should provide sufficient lighting for softies, LPS and easier SPS
- 1 Vortech MP10QD wavemaker. Might purchase another one if one doesn’t suffice, but I assume that one can cover the system needs.
- D-Flow Designs media baskets to improve filtration
- 3deep bottom intake covers, as i’ve heard this also helps with filtration.
- Fluval M150 heater which fits in the rear chamber
- AF rock
- CaribSea Original Grade Ocean Direct live sand
- RODI unit and water buckets for mixing station
Future considerations gear-wise:
- I’m planning on adding a Tunze 9001 DC skimmer, but will wait untill this becomes neccessary after the initial setup.
- DC return pump upgrade. I will see how the stock pump will perform, but i’m most likely going to upgrade to a quiet and reliable return pump.
- An extra Vortech, if I need that extra flow in the tank.
- Automated and programmable Fluval fish feeder
- Doser pumps
Plans for livestock:
I will do my best to stay patient with livestock additions, and take it slowly to allow the system to mature itself biologically.
First I plan on adding a Ocellaris clownfish pair, with a few hardy softies, probably rhodactis, ricordea, toadstools. Shortly after, I will add a CUC consisting of snails, hermits and shrimp. After a month I plan on adding a utilitarian fish of some kind, possibly a tailspot blenny or sixline wrasse, which will help control unwanted pests (blenny for algae, wrasse for pests). Hereafter I move on to more decorative livestock choices, most likely a Royal Gramma and maybe a pygmy angelfish. Here I will also start adding LPS, most likely euphyllia (hammer and torch), acans, scolymia. After 4-6 months, I might consider adding easy SPS, such as a birdsnest, pocillopora or something like that, towards the top of the aquascape.
Key learning points:
Now, listen - there is a lot of trash-talking about the Fluval Flex on several forums and Facebook groups. Some of them are grounded in truth, and some of them I suspect are just down to poor husbandry and planning. There are some issues with the Flex, but you can mod yourself out of it.
Lets start with filtration. This is possibly the single largest complaint that people have. The rear filtration chamber in this tank is not well thought through design-wise, and it therefore requires some modifications for optimal functioning. First reported improvement are alternative media baskets - there are several 3D-printed options for this. A lot of US reefers can purchase media baskets designed for the Flex 123 from InTank, and EU reefers like myself can purchase media baskets from 3deep or D-Flow Designs from the UK. These are supposed to force the waterflow through the filter media top-down. The provided sponge filters are very ineffective, as those often can be too dense and clogged up too quickly, leading to poor water flow and circulation in the rear chamber (freshwater folks know what i’m talking about here with dense sponge filter media).
Furthermore, there are many complaints surrounding the seal of the rear chamber, and here we’re talking the entire attachment to the back pane glass. Some have experienced that the silicone seal isn’t tight, and suspects that water flows through the bottom and sides of the rear chamber. Inspecting my tank, the silicone seal looks tight, so this might only be in some unlucky ones, but I will update on this.
Furthermore, the intakes are both in the top and bottom of the rear chamber box. Some report that it works fine with the media basket upgrades, and some report that you have to additionally purchase covers for the bottom intakes as well. This is to prevent sand and detritus from building up in the bottom of the chamber, and to force water through the top intakes to improve surface skimming capabilities and water flow through the filter media. I purchased bottom filter intake covers from 3deep, and will update if these improve the filtration.
Finally on filtration - some Flex reefers complain about the stock return pump, either that is isn’t strong enough, or that it is noisy. There are different experiences with this, and it depends on your system needs. If you got powerful wavemakers in the tank, you might be able to skip the return pump upgrade, as you wont rely much on that pump for overall flow in the tank. I will update on this as well, and see if an upgrade is neccessary.
Lets talk about the lighting. Some people absolutely despise the stock lighting, claiming it isnt strong enough. Many have upgraded to 2 stock lights, and others have completely replaced the lid and lighting, and bought more expensive lights for the tank, like AI Primes or Radions together with a mesg or acrylic lid. However, my common sense tells me that this could be beginner panic. The lights have been proven from several Flex reefers to be sufficient for healthy softies, LPS and even some SPS with 2 lights. One light can even suffice for softies and several LPS. The light sits very closely to the water, and the tank itself is quite shallow - which means that the light can easily penetrate the water. So I wouldn’t worry about this at first. Try out the stock light and see how well you’re doing. In my opinion, many reefers, especially beginners, are quick to correlate their issues with coral to lighting, even though it is only one factor alongside especially water parameters, water flow and coral placement. The Fluval 3.0 Marine light has a nice and basic spectrum control, and the app control is very easy. Several have had success with this light in the Flex. I would say that an upgrade in lighting should only be done if you want to grow difficult SPS species.
Lets talk about the lid. The lid has many claimed benefits. One thing is in regards to evaporation, which is almost non-existent in this tank. This also means you dont have to go through the hassle of purchasing and using an ATO with this tank.
Also, if you own a curious cat like me, this is a great way to keep them out of your tank.
However, there have been some issues related to the lid, especially for Flex owners who live in warmer parts of the world. The lighting plus the lid can generate some unwanted heat. Not by much, but a little. This means, that if you live in a warm climate, this might become an issue for you. I live in Denmark, and most of the year here is cold and terrible, so I wont worry for my circumstances, even though summers are definitely getting hotter, with 1-2 weeks possibly reaching 30-33 degrees celsius a year. But this is possibly something you should consider, if you live in an area where you consistently have high room temperatures above 23 degrees celsius.
Lets talk about the tank itself. I’m sure you can find horror stories all over the place about all kinds of tanks. One of the few bad stories out there is that the Flex silicone isn’t strong enough, and therefore lead to leaks for some. However, remember, on social media, you always hear the bad stories first. There are maaany who never had this issue. The bad stories might as well have been basic failure, such as a tank and stand which isn’t perfectly levelled on the floor. I wouldn’t worry about this either - follow standard procedure as you would with any aquarium, and check for any issues in the silicone and glass before filling with water.
I will post pictures and document my journey over the next couple of months, in this thread, in hopes of sharing experiences, useful information and more to fellow potential or current Flex owners and Nano reefers, so that you wont have too many unanswered questions or worries regarding your reefing journey.
I’m finally getting into the saltwater world again! Two weeks ago, my Fluval Flex 123 (32.5g) reef got delivered. Had some trouble with getting the stand delivered, as the postal service had trouble transporting it, but now I finally got it.
For everyone else considering a Flex 32.5g, I want to list my key learning points so far, and my journey. This way, I can share all the filtered information i’ve gathered about this tank from forums, Facebook groups and Reddit.
I purchased a few pieces of gear and bits to optimize the system:
- An extra Fluval 3.0 Marine LED 75cm which should provide sufficient lighting for softies, LPS and easier SPS
- 1 Vortech MP10QD wavemaker. Might purchase another one if one doesn’t suffice, but I assume that one can cover the system needs.
- D-Flow Designs media baskets to improve filtration
- 3deep bottom intake covers, as i’ve heard this also helps with filtration.
- Fluval M150 heater which fits in the rear chamber
- AF rock
- CaribSea Original Grade Ocean Direct live sand
- RODI unit and water buckets for mixing station
Future considerations gear-wise:
- I’m planning on adding a Tunze 9001 DC skimmer, but will wait untill this becomes neccessary after the initial setup.
- DC return pump upgrade. I will see how the stock pump will perform, but i’m most likely going to upgrade to a quiet and reliable return pump.
- An extra Vortech, if I need that extra flow in the tank.
- Automated and programmable Fluval fish feeder
- Doser pumps
Plans for livestock:
I will do my best to stay patient with livestock additions, and take it slowly to allow the system to mature itself biologically.
First I plan on adding a Ocellaris clownfish pair, with a few hardy softies, probably rhodactis, ricordea, toadstools. Shortly after, I will add a CUC consisting of snails, hermits and shrimp. After a month I plan on adding a utilitarian fish of some kind, possibly a tailspot blenny or sixline wrasse, which will help control unwanted pests (blenny for algae, wrasse for pests). Hereafter I move on to more decorative livestock choices, most likely a Royal Gramma and maybe a pygmy angelfish. Here I will also start adding LPS, most likely euphyllia (hammer and torch), acans, scolymia. After 4-6 months, I might consider adding easy SPS, such as a birdsnest, pocillopora or something like that, towards the top of the aquascape.
Key learning points:
Now, listen - there is a lot of trash-talking about the Fluval Flex on several forums and Facebook groups. Some of them are grounded in truth, and some of them I suspect are just down to poor husbandry and planning. There are some issues with the Flex, but you can mod yourself out of it.
Lets start with filtration. This is possibly the single largest complaint that people have. The rear filtration chamber in this tank is not well thought through design-wise, and it therefore requires some modifications for optimal functioning. First reported improvement are alternative media baskets - there are several 3D-printed options for this. A lot of US reefers can purchase media baskets designed for the Flex 123 from InTank, and EU reefers like myself can purchase media baskets from 3deep or D-Flow Designs from the UK. These are supposed to force the waterflow through the filter media top-down. The provided sponge filters are very ineffective, as those often can be too dense and clogged up too quickly, leading to poor water flow and circulation in the rear chamber (freshwater folks know what i’m talking about here with dense sponge filter media).
Furthermore, there are many complaints surrounding the seal of the rear chamber, and here we’re talking the entire attachment to the back pane glass. Some have experienced that the silicone seal isn’t tight, and suspects that water flows through the bottom and sides of the rear chamber. Inspecting my tank, the silicone seal looks tight, so this might only be in some unlucky ones, but I will update on this.
Furthermore, the intakes are both in the top and bottom of the rear chamber box. Some report that it works fine with the media basket upgrades, and some report that you have to additionally purchase covers for the bottom intakes as well. This is to prevent sand and detritus from building up in the bottom of the chamber, and to force water through the top intakes to improve surface skimming capabilities and water flow through the filter media. I purchased bottom filter intake covers from 3deep, and will update if these improve the filtration.
Finally on filtration - some Flex reefers complain about the stock return pump, either that is isn’t strong enough, or that it is noisy. There are different experiences with this, and it depends on your system needs. If you got powerful wavemakers in the tank, you might be able to skip the return pump upgrade, as you wont rely much on that pump for overall flow in the tank. I will update on this as well, and see if an upgrade is neccessary.
Lets talk about the lighting. Some people absolutely despise the stock lighting, claiming it isnt strong enough. Many have upgraded to 2 stock lights, and others have completely replaced the lid and lighting, and bought more expensive lights for the tank, like AI Primes or Radions together with a mesg or acrylic lid. However, my common sense tells me that this could be beginner panic. The lights have been proven from several Flex reefers to be sufficient for healthy softies, LPS and even some SPS with 2 lights. One light can even suffice for softies and several LPS. The light sits very closely to the water, and the tank itself is quite shallow - which means that the light can easily penetrate the water. So I wouldn’t worry about this at first. Try out the stock light and see how well you’re doing. In my opinion, many reefers, especially beginners, are quick to correlate their issues with coral to lighting, even though it is only one factor alongside especially water parameters, water flow and coral placement. The Fluval 3.0 Marine light has a nice and basic spectrum control, and the app control is very easy. Several have had success with this light in the Flex. I would say that an upgrade in lighting should only be done if you want to grow difficult SPS species.
Lets talk about the lid. The lid has many claimed benefits. One thing is in regards to evaporation, which is almost non-existent in this tank. This also means you dont have to go through the hassle of purchasing and using an ATO with this tank.
Also, if you own a curious cat like me, this is a great way to keep them out of your tank.
However, there have been some issues related to the lid, especially for Flex owners who live in warmer parts of the world. The lighting plus the lid can generate some unwanted heat. Not by much, but a little. This means, that if you live in a warm climate, this might become an issue for you. I live in Denmark, and most of the year here is cold and terrible, so I wont worry for my circumstances, even though summers are definitely getting hotter, with 1-2 weeks possibly reaching 30-33 degrees celsius a year. But this is possibly something you should consider, if you live in an area where you consistently have high room temperatures above 23 degrees celsius.
Lets talk about the tank itself. I’m sure you can find horror stories all over the place about all kinds of tanks. One of the few bad stories out there is that the Flex silicone isn’t strong enough, and therefore lead to leaks for some. However, remember, on social media, you always hear the bad stories first. There are maaany who never had this issue. The bad stories might as well have been basic failure, such as a tank and stand which isn’t perfectly levelled on the floor. I wouldn’t worry about this either - follow standard procedure as you would with any aquarium, and check for any issues in the silicone and glass before filling with water.
I will post pictures and document my journey over the next couple of months, in this thread, in hopes of sharing experiences, useful information and more to fellow potential or current Flex owners and Nano reefers, so that you wont have too many unanswered questions or worries regarding your reefing journey.
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