# Flex or Edge?



## alang (Nov 25, 2007)

Its been a long time since my last tank. I had a 55g high tech for many years until it crashed hard. I didn't have the bandwidth to start over so I sold everything.
I have since retired and really want to get another tank. I no longer have the room for a big tank so nano it is. I also don't want to get into the amount of maintenance of a high tech setup.

I have been researching tanks and really like the look of the fluval tanks, especially the edge. I am looking at the larger sizes of these tanks since my only experience is a large tank.
The lighting of the edge concerns me, but I think an island scape would do alright directly under the light. Those with these tanks, does the light work well enough for good plant growth at the sides?

The aspect of the edge that I like the most is the top view since its going to be on a low credenza, however, I am concerned with the reduced surface area for gas exchange. I have read several threads where people keep the water level below the top which would defeat the reason I like this tank.

For someone getting back into the hobby after several years that has never done a nano or low tech tank, does the edge add additional complications that would make the flex a better choice?


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## DaveKS (Apr 2, 2019)

In a low tech that your not injecting CO2 the limited water surface to atmosphere contact area for proper gas exchange would keep me away from Edge. 

I’d rather have Spec 16.

Even better get a Water Box 20 and pick my own light like Chihiros etc that has built in ramp up/down programming as well as variable intensity so you can dial it in just right for your needs.


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## Thelongsnail (Dec 2, 2015)

I have the 15g flex and it's ...alright.

Pros:
-Ease of maintenance
-Decent internal filter
-Heater can be hidden in the back compartment
-Decent enough stock light to grow easy plants with little to no algae. I have:
-2x amazon swords, bolbitis fern, anubias sp., water lettuce, moss balls 
-Anubias coffeefolia, java fern, java moss, buce sp., mondo grass (emergent)

Cons:
-Small fish can and will end up in the filter compartments
-Jumping fish can and will end up in the filter compartments, and on top of filter media
-Not much room for fish to swim lengths, compared to longer tanks of the same volume
-The flow can be too strong for long-finned bettas, and will need modifying in some way

As others have said, I'd probably go with the Spec 16. No personal experience with it, but it has good reviews and looks pretty decent.


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## babystarz (Sep 25, 2012)

I would steer you away from the Fluval Flex. I really disliked the tank cover and the lighting it comes with was pathetic (probably not helped by the fact that my light was stuck on a rainbow light cycle and the remote was non-responsive after changing the battery so it was a full-time disco lmao). Also the flow from the filter pump was WAY too much for most fish. I did need to modify it in a few different spots (I used zip ties to attach a sponge to the grate over the intake to prevent fish from going into the back chamber of the tank and then two more sponge pieces in the outflow to slow the current). 

I just don't think it's an ideal tank to start out on and it's definitely not great for plants without adding more lights to the inside of the cover yourself. I only had it up and running for a few months before taking it down and it's been sitting empty - I am planning on giving it away.

The Flex simply isn't suited for planted tanks or many fish out of the box. If I did it over again I'd buy a tank/cover/equipment separately because if I'm going to spend the resources on customizing something I'd rather not have to do it on one of these kit tanks. You need to do more research in that case but the outcome will be better and you'll learn more and have a better understanding of how each piece of equipment works and impacts your planted tank.


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## alang (Nov 25, 2007)

Thanks for the input. I have seen many posts around the net where people use both for successful planted tanks. After these responses I think I will keep looking for more reasonable options.


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## Roomba960 (Jun 13, 2019)

*Flex*

It was seeing a Flex in a pet store recently that convinced me to get my old 12g AIO running as a planted tank after a four year hiatus from reef. It was gorgeous.

Everything looked stock and I think it was even dimmed but it sure looked gorgeous with a full mat of something and some cardinals. A very striking and elegant tank.


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## WillR1496 (Apr 1, 2019)

Not sure if you've seen it, but Fluval came out with a 32g Fluval Flex. They did a small production to see how things went and they sold out. Took them months to get them back in the stores. Recently saw one at my LFS and it's real nice. The only issue is that I wasn't too fond of the stand it comes with. I liked the original one better.


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## shewolf (Mar 15, 2019)

If you decide to go with the Flex and intend to keep smaller fish or shrimp, you will most definitely have to modify the intakes at the top and bottom. Coarse sponge or quilt batting cut to size to fit inside the removable grills that go over both intakes will work. Otherwise, as stated above, the fish/shrimp will get sucked into the filter compartment.

I have only the 9 gallon, and it has it's pros and cons, but looking back, I honestly wish I'd gone with something else, even just a plain ole 10 gallon. Good luck with whatever you decide.


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## livebearerlove (Aug 20, 2013)

I would suggest to stay away from the edge.... depending on how you use it.
History: I won a international aquascaping competition with a fluva edge. I did it because I brought the tank from UK to HK and it fit into my interior design. I wish I never did...
Flaws:

Lighting is centered- no dimmer and fills only a small amount of space directly in the middle of the tank.....can cause big issues if you plant past the 6 inch area. Low lighting allows for mosses, anubias, etc. But managing them can be difficult.
Aquascaping 'challenges'.... trimmings (which are inevidable) float under the glass... grabbing them is a massive mess.
Livestock: Catching fish! has been nothing but a huge issue. Hours of strange sweeping motion with your hand in the tank....
Pros:
It is a decent HOB- that actually has worked pretty flawlessly for me in multiple countries (three to be exact)
It does look sleek- fit in well. But ultimately I broke down and replaced it with a 'frameless open top'

Here is what I did with it before it grew out- before the competition. After that I couldnt trim it fast enough or clean up the trims well enough. I just emptied mine last night.... if you want it- its yours.... lol.


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## alang (Nov 25, 2007)

livebearerlove said:


> if you want it- its yours.... lol.


Can't beat free even if its a failure! However I think shipping from MN to CA would be more than the cost of the tank itself lol 
Thanks for the generous offer though :wink2:


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## Couesfanatic (Sep 28, 2009)

I'd get the Nuvo 10 personally.


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## yanyan (Jun 13, 2019)

I hate to spoil your party, but I suggest not getting any fish tank with built in sump. 

Cons:
1. Nano fish like my Pea Puffer, Pygmy Cory, and Otos all at one time got stuck in one of the compartment/chamber of the rear sump of my Coralife Biocube 16. Maybe through the slit filter intake, idk, but they all got stuck and lived somehow until i rescued them.
2. Hard to clean rear sump. It was an irritating experience to clean the sump part of the tank. Plus algae builds up real quick back there and clogs the waterpump and all mechanical filter with detritus and algae. When mech filter clogs up, the water level drops in the water pump chamber and runs it dry.


Get a 29g, 20long, 15g or a 10g instead and run either HOB or canister and not worry about fish getting stuck or hard to reach/clean sump getting clogged up. I have my Biocube16 which i spent $250+ just collecting dust in the storage and replaced it with 20 long for $20 dollar per gallon from Petco and am happier. Big regret on Biocube16 which was my first fish tank.


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## somewhatshocked (Aug 8, 2011)

I'd stay away from the Edge for reasons already mentioned.

But don't shy away from tanks with built-in filtration/sumps. They're perfectly fine. The Flex and Spec lines are super-easy to modify to prevent critters from getting into the rear compartments. They work fine for tons of people on the forum.


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## Blue Ridge Reef (Feb 10, 2008)

I bought two of the little 5-7 gallon Edge's when they first came out for shrimp tanks. I like them aesthetically but hated them functionally. I found them frustrating to grow plants in so finally put bettas in them. That wasn't even ideal. They are both in my storage now. The sealed glass top with the tiny opening was the fatal flaw in those small ones, not sure that's what is going on with the larger ones. Fluval's Osaka and Vincenza lines were two of my all-time favorite kits and I have both running today. I don't know if my complaints are applicable to their larger offerings but those little Edges were not suitable for my purposes at all.


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