Tank Buyer's Guide & Glossary

Difference Between RTA and RDA

For our djuice purposes both do a similar job, the chief difference is how djuice feeds the wick.  In RTAs, djuice soaks through the wick from a tank reservoir using capilliary action, whereas RDAs (rebuildable dripping atomisers) are normally manually fed directly from a juice bottle or syringe by dripping from above.

But which is best?  Well here we're concentrating on RTAs, but here are a few points of interest..

• RDAs can be smaller, lighter, simpler and cheaper than RTAs

• RDAs tend to have much roomier build decks than RTAs, perhaps easier to wick

• On many RDAs, very large double coils can be fitted (see pic), far larger than expected from dual coil RTAs and generally much larger than ever needed for dimitri use.

• RDAs need frequent topping up with juice, typically approx every 2 tokes (to be safe) unless juice is pooled around the wick base

• If RDAs contain sufficient juice to form a pool, this will quickly leak out if laid on its side. Properly set up RTAs generally remain leak-free if laid on their sides

• Inspecting the wick condition between tokes is much easier with RDAs, which can be a great advantage

• I've found RDAs to be much more convenient for testing out many different coils/wires etc

Note: For the remainder of this page, we'll speak only of "Direct To Lung" unless specifically mentioned, i.e. so called "Sub Ohm" RTAs

Juice Capacity

Straight vs Bubble Glasses: Unless you have a specific reason, I strongly recommend using the straight glass on your tank.  If not already included, I suggest ordering an aftermarket straight glass (e.g. from Amazon/Wish/Ebay). Tank capacity will normally be expanded (by ~2-5ml or more) when using the bubble glass which will usually be far more than ideal for Dimitri, but why do I think this?

• It's wise to stop vaping when the tank levels runs low. With the bubble glass fitted, this visible level will be reached when the tank contains a far greater quantity of juice

• The extra capacity endowed by the bubble glass has no real benefits.  For my tastes, anything more than roughly 3ml capacity (including the juice soaked into the coil) starts to become disadvantageous. For example a full 5ml of juice may be more than a wick can handle without noticeable deterioration, especially if non-pristine Dimitri is used and/or higher wattages/long tokes are used

• If a problem occurs in a tank, such as a suspected burned wick, clogging, sudden leak, strange noises when toking, etc- it's much easier to investigate when a tank is filled with less juice.  Plus if juice becomes contaminated with charred wick particles, then this will not affect as much juice.

Wire or Mesh Build Deck

DTL "sub ohm" tanks are available with mesh or wire build decks.  Both can be used for Dimitri but which is best? Well here we concentrate on wire decks as I much prefer them for Dimitri.  I don't recommend mesh RTAs for Dimitri, here's some pros & cons..

• mesh decks tends to heat up to vaping temperature much quicker without resorting to Wattage-modifying mod box settings (e.g. "Boost", "Pre-Heat" or "VPC curves").  Cool-down time is also much quicker.

• It appears much easier to get wire decks producing Dimitri vapour at the right temperature/concentration for optimum punch and efficiency

• It's easy to set up mesh decks in a way that produces cooler more abundant vapour, which can seem smoother to newbies, but can be dreadfully vape inefficient with alarming juice consumption coupled with feeble effects

• The voluminous wick of mesh decks means a tank can show no juice level in the glass but still have significant amounts of vapable juice remaining,  which can make it awkward to judge when to stop vaping when the tank runs low

Knockoff versus Genuine Tanks

There's currently an amazing selection of knockoff clone RTAs on Chinese retail sites at roughly half the price of genuine models.  Most of my early RTAs are clones and I've generally had great service from them. It's true that quality varies, but most have impressed and some are difficult to believe as inferior to genuine.  Of course, we omit morality issue in buying a product which shortcut development costs by stealing the design of others!

So speaking in very general terms, genine RTAs .....

• can often have a silky smooth assembly, less chance of cross threading or stiff parts

• normally have less residial manufacturing swarf to clean up, often smoother machined surfaces

• usually have better finish on the 510 connector centre pin (so less likely to scratch mod's mating connector, and cause small resistance resistance fluctuations) 

• sometimes have less chance of O-rings getting trapped/pinched upon assembly, or coming adrift on disassembly

• normally come in proper presentation box (rather than plactic "squeeze box" that clones often use) and include OEM accessories.

• possibly more likely to arrive undamaged, and without parts missing (I've never had any like this, but others have reported it) 

Notable aspects of clones include

• Almost all of my clones have been very useable and most very sound

• Much lower cost than genuine tanks

• Easily available from Aliexpress (USA deliveries from products disguised as non-vape kit), Wish, 2fDeal

• Variable quality, but most of mine have been very impressive for the price

• My clones have generally contained much more residual swarf/tiny shards than genuine models, which I've cleaned out before use

• Clones can sometimes be supplied with only 2 or 3 spare O-rings, not a full set (usually 7 for a screw-top RTA).  Replacements can be difficult to source if tank-specific kits aren't available. I'd suggest only purchasing tanks which eiher incude a full set of spare rings, or where spares kits are easily available.

• A viable way of testing many different tank types at low purchase cost

Top/Bottom Airflow

Refers to the position of the air inlet vents being high or low, the vaping experience of these is very similar. Top airflow tanks are often sold as "leak proof", but this is nonsense. Any tank can leak, for example if it has damaged/missing O-rings, or perhaps has been carelessly filled. The leaking difference between top/bottom airflow is when juice finds its way into the inner chamber (not soaked into the cotton wick) - for example entering via the centre hole while filling or juice bypassing around the cotton in the juice wells.  On bottom AF tanks, this can leak out almost immediately.  However, with top airflow devices this will first accumulate in the inner chamber (maybe causing flooding, gurgling or if bad, juice ingestion upon toking) and then leak out of the air inlet holes when the tank is next laid on its side. In my experience, if any top or bottom airflow tank is wicked, filled, used and stored correctly then there will be few if any leak problems. 

But which is best? Well personally I don't find much difference between them, but here's a general summary..

• Bottom AF RTAs are often slightly simpler, having no inner airflow chamber (see pic), a part which is common on top AF tanks

• Many top AF devices (but not the Kylins) have part of their juice reservoir hidden within the base shell, which makes it more awkward to judge amount of juice remaining when the level runs low (see Base Resident Juice Pools below).  Bottom AF (e.g. the Destiny) often have their deck raised above the base-resident airway, elevating the reservoir into full or almost full view through the glass.

• Top AF RTAs have a potential buffer against some causes of external leakage (e.g. juice accumulating in the inner chamber), which can be useful in some ways, but means that leaks may not be immediately apparent/corrected and can result in a potentially large loss of juice when inadvertently laid on their side.

• Leaks from bottom AF devices can often result in juice being deposited on the mod, risking juice ingress and potential damage over time.  Common leakage from top AF tanks will often manifest when laid on the side, and juice will not come into contact with the mod. 

• Top airflow tanks seem more likely to emit a loud pop about 2 seconds into a fire cycle, however there is an easy workaround (i.e. hold the fire button with the mod held away from the mouth, allow the mod to pop, release the button, and then toke as normal)

Dual/single Coil Build Decks

Whilst MTL & RDL RTAs tend to be designed to take only one coil, many DTL "sub ohm" RTAs have the option of fitting either one or two.  Almost all top airflow dual coil (not all) tanks can be fitted with a single coil if desired (which is generally more suited for dimitri juice) but the setup technique may need a very slight modification owing to the juice well openings being designed to accommodate cotton from two coils, not one.

For dimitri purposes, the issues of dual/single coils can be generalised

• For Dimtri, with a Direct To Lung tank,  just one coil is IME generally adequate able to produce vapour within the efficient range of temperature and concentration.  For more info, see the rebuildable tanks FAQ

• Most top airflow dual-coil decks are well-suited to fitting of a single coil by adjusting the position of the coil centrally (not the Thunderhead Blaze, owing to the contouring of its deck).  Bottom airflow dual deck RTAs often have two lower air ports (one for each coil) so would not be suitable for single coil operation

• When dual decks are fitted with a single coil, unused terminals act as spares in case of thread wear or lost screws (note that even some single-coil tanks (e.g. the Dead Rabbit solo) have two sets of terminals to cater for both clockwise and anticlockwise coil windings)

• Dual coil decks often have smaller terminals/terminal screws so super thick gauge wire may not fit them (but still good for what we want)

• Dual coil decks are often narrower between terminals, meaning that less turns of a coil will fit in them (all I've tried are acceptable)

• Single coil decks can vary greatly in size and available space

Spare Parts Availability

This varies so much between tanks, so I suggest some research prior to purchase, for example

• Glasses  easily obtainable for common tanks from Amazon/Ebay/2fdeal/Wish.  If you live in a country where Aliexpress vape links show up, this can be invaluable.

• O-ring kits available for some tanks, but so far I've only seen them sold on Aliexpress.  If unavailable, don't assume a generic box of assorted O-rings will solve your spares problems, it almost certainly won't.  Ring tolerances seems to be not only extremely fine, but also very difficult to measure owing to compressibility.  And even if you manage to obtain accurate thickness/diameter dimensions, sourcing/ordering these in smaller quantities can difficult and expensive - personally I'd simply order an entire new tank instead.  

• Grub screws for the terminals can be measured and ordered from Amazon/Ebay.  They'll probably be either M2.5 or M3 cup point allen or flat head and about 4-6mm in length (obviously, measure yours before ordering!)

For me, the Zeus X is by far the best for spares availability (using UK Aliexpress). I have replacement glasses, complete build deck assemblies, o-ring kits, and even spare inner airflow chambers.  Sadly this is not the case with other tanks so if spares availability is important to you then I suggest research prior to purchasing.

Screw/Sliding Fill Caps

All the rebuildable tanks reviewed on my pages have screw caps. Some are mutli-turn, whilst others are "quick-fit" quarter turn but I'm fine with either variant. However, personally I detest sliding caps. I have them on two of my tanks and now avoid at all costs. Not everyone agrees but here are my reasons..

• Sliding caps often have a small arrow or dot maked on their caps to indicate the direction of push to open.  Even when present they can very difficult to spot in poor light, expecially if you have imperfect vision.  Screw tops are so much quicker and arguably much less frustrating to open

• Regarding the sealing gasket that keeps the reservoir air-tight on sliding cap fittings, it's proprietary so can't be substituted or easily home-fabricated and I've never come across any tank which includes a spare, nor seen any aftermarket replacements. And in some tanks (e.g the Profile M), these can be very vulnerable to damage in which case will likely result in scrapping the entire tank.  

• Upon sliding open, normally only one fill port is exposed which is not ideal when filling with thicker d-juice, which can take a little time to settle. Therefore it's handy to have two opposite fill ports available to divide out the filling operation

• With a sliding fill cap, I can never have 100% confidence that the tank has sealed fully.  It's essential that top gaskets provide a reliable air tight seal to maintain a slight vacuum in the top air gap to reduce flooding/leakage risk. With a screw cap, a more predicatable O-ring compression provides haptic feedback for much greater confidence.

Base-resident Juice Pools

On many top AF RTAs, the inside of base shell serves as the lower part of the juice reservoir, often holding close to an entire 1ml of "hidden" juice. This means that once the juice level falls below the visible level of the glass, it can be tricky to know when to stop vaping.  In any case, it's arguably wise to exercise caution with low juice levels (reduced Wattage, shorter tokes), but the hidden juice can often be revealed by holding the tank at a slight angle.  Some may prefer this as a  "safety reserve", but I prefer the entire reservoir in view. 

Not all top AF tanks have this.  For one, the Kylin Mini V2 has a different juice feed arrangement and doesn't use its base as a juice pool, instead it houses a rotation bearing for its build deck.