Cthulhu RTA, courtesy of Cthulhumod.com!

SirRisc reviews
What up vapefam!

Sirrisc is back with another RTA review courtesy of Cthulhumod.com!

I’m a little late to the party, but I finally managed to make time to write the review for the Cthulhu RTA. (Sorry guys!)

Allow me to spoil the entire thing by saying in advance, it’s fucking awesome.


“The Thing cannot be described – there is no language for such abysms of shrieking and immemorial lunacy, such eldritch contradictions of all matter, force, and cosmic order. A mountain walked or stumbled.
If I say that my somewhat extravagant imagination yielded simultaneous pictures of an octopus, a dragon, and a human caricature, I shall not be unfaithful to the spirit of the thing.
A pulpy, tentacled head surmounted a grotesque and scaly body with rudimentary wings; but it was the general outline of the whole which made it most shockingly frightful.”

Cthulhu Mod is a relatively new player on the vaping market, but their introduction hasn’t gone unnoticed.

With the Cthulhu RTA they set the bar high and they deliver a high quality RTA that’ll blow your socks off.

The impressiveness starts at the packaging, continues on with the amount of extra o-rings and grub screws, and then there’s the RTA itself…


Cthulhu RTA


* Medical Grade Stainless Steel
* Pyrex/glass tank with 4ml capacity.
* Adjustable 3mm airflow holes
* Bottom fill screw
* Top fill mechanism with 4 fill holes
* Copper 510 connection
* Laser etched Cthulhu in the chimney
* 2*3mm independent airflow holes in the deck
* 3 post design, 4*1.6mm wireholes
* Dual coil design
* Can take high VG liquids (I tested up to 95%VG)


As I mentioned above, even the packaging is impressive.
The entire RTA and its accessories come in a plastic casing with the logo printed on top, and a QR code you can scan with your smartphone.
The QR code points you to their website where you can find all info on the RTA.

The casing is strong, clean and fits comfortably in my vapecase. It’s now the permanent home to my hex keys, coil jig and a couple of spare driptips.

The casing holds 3 plastic bags.

One with the RTA itself, one with a couple of spare screws, and one with a bunch of spare o-rings, another set of screws, 2 prebuilt coils, a hex key and the infamous blue screwdriver. (Yay, another one for the collection!)
On the bottom of the casing is a piece of cardboard with the code to check authenticity, and a link to the website. Again, a QR code is printed for easy access.


Ok, I don’t know where to start on this because it compares to pretty much any dual coil RTA out there.
It does what it’s supposed to do, and it does so in true Cthulhu fashion: f’ing great.

The first time you screw everything apart it may seem a little daunting, because there are a lot of parts.
It’s nowhere near as bad as the KFL4 though, that one is just plain ridiculous.
Once you screw everything back together it just makes sense, the design was done like this for a reason.

Is it worth all the hype? Yes, it is. Just because the performance is so good, it’s no wonder people are raving on about this RTA.

Could it be improved? Yes, definitely. There are a few things that irk me, but considering the guys from Cthulhumod are very active in the community they have also fixed a few of these issues in the second and third batch of the RTA.

One of the major issues for me was the airflow ring. Holy shit, that thing is tighter than an anti-vaping politicians asshole.
The guys at Cthulhumod state that you need to close off the airflow to fill the tank from the top, but you’ll need some brute force to move the airflow ring.
A somewhat unorthodox fix is to sand down the o-ring a little bit, or more conventionally replace the o-ring with a thinner model.
It’ll still be tight enough to hold the airflow ring in place, but at least it’ll be able to move.
This has been reported as fixed in the second batch. Good one, Cthulhu guys!

Another issue I ran into was the screw that threads onto the chimney to hold the tank together.
It’s easy to grab and once it’s tightened it won’t move, which is good. It’s getting it to thread that’s the hard part.
The threading at the top seems to be a little too loose making the screw tip over on the threads, effectively increasing the risk of crossthreading your chimney.
Again the guys at Cthulhumod fixed this in a later batch. These guys don’t play around, they want this RTA to be a success. (and quite frankly, they’re doing a stellar job)

Leaking? Yes, sometimes it’ll leak a bit from the airflow holes when I just filled it from the top.
Why this happens is beyond me, I’ve had comments that it must be my wicking but I’ve not found a solution to it yet. No matter how I wick it, it’ll leak sometimes.
Once I take a few toots however, it stops leaking and works perfect for the rest of the tank.


The Cthulhu RTA is a beauty. It’s simple, yet so pretty.
The medical grade steel used has a hazy finish and seems to be fairly scratchproof.
The glass is fairly thick (though that of the Goblin is thicker), and shows the laser etched Cthulhu on the chimney.

For those of you wondering about replacing parts: No, the KFL style bellcaps do NOT fit, and neither do the Goblin accessories.
The Cthulhu also comes with a driptip with a fairly wide bore. The bore is the same as the chimney, making it one straight opening to the chamber.
The driptip is plain steel, no logo or anything but it looks good.


I could go into detail on how to build this thing, but I’ll happily point you to Ironhammer5’s tutorial for this.
His wicking technique works fine, and seems to take up to 95%VG without dryhits.

For good measure, I built mine to 0.7ohm at first and it performed nicely. I now have a 0.4ohm build in there and it’s even better.

This RTA was made for lower builds it seems. Given the airflow is so big and the juicechannels are humongous, it only seems logical that this will take low builds and higher wattages.

One tip I can give you is to keep your coils below 2.8mm. Anything above that will risk touching the chimney and shorting out your RTA or mod.

On that note, please use an ohmreader when building. It’s a cheap but effective way of detecting shorts and it’ll be cheaper than surgery.

Pros and cons


* Big clouds
* Comes with a driptip
* Cthulhu!
* 4ml tank
* Easy to build
* Easy to wick
* Huuuuuuge juicechannels
* Amazing airflow
* Medical grade steel
* Glass tank
* Cthulhu!
* Awesome packaging
* Looks f’ing beautiful
* Lots of spare o-rings and screws
* Good value for money
* Excellent performance


* Top screw is a little iffy (fixed)
* Airflow ring is too tight (fixed)
* Tastes of machining oil, wash it before use! (fixed)
* Leaks from the airflow holes sometimes after filling
* Less flavorful as the Goblin
* No spare glass included
* Some tanks had some steel residu (fixed)
* A little hard to come by sometimes due to the limited production*

*Coïncidently they are still looking for distributors and retailers, so if you have a vapeshop or your favorite shop isn’t stocking them yet you should contact them at [email protected]!


In conclusion

The Cthulhu is worth the hype. It really is.
The performance is great and rivals RDAs in terms of vapor production, but not entirely in terms of flavor.
It looks great, the Cthulhu etched on the chimney is definitely an eyecatcher.
There are a few quirks, but most are fixed already or are being fixed in a later batch.
The guys from Cthulhumod are very actively persueing perfection by listening to the community, something other comanies should definitely improve upon.

In closing I would like to thank Joshua from Cthulhumod for sending me this RTA for review.
And of course I would like to thank all of you for reading, I wouldn’t be able to review without you.

I’m always looking for more opportunities to review, so get in touch if you want me to review something from you! Juice, RTA, RDA, mods… it’s all welcome and I’m sure we can work something out!

#staycloudy !

*SirRisc disappears in a forest fruit scented cloud of vapor*


About author View all posts Autor website


Vaping in Belgium since 2014.
Moderator on /r/ecr_eu, DIY afficionado, likes good flavors and sturdy devices.
Current favorite setup: P4U IPV D2, Wotofo Troll.