a smal 4.8 gallon aquarium sitting on a desk with a small potted plant next to it. Peaceful with several small colorful corals inside as well as an orange clownfish.

Saltwater Aquarium Tips For Beginners: Don’t Fail Year One

1. Buy An RODI Filter

As it should be, my top saltwater aquarium tip for beginners is to purchase an RO/DI filter on day one.

I’ve mentioned this a lot in the past, but by purchasing an RODI filter, not only are you being really kind to your animals, but you are saving a ton of money… both in the short and long term.

Think about it like this: you can either buy RODI water from your local fish store, you can buy pre-made saltwater from your local fish store, or you can go to the grocery store and buy jugs or 5-gallon containers of filtered water and then mix it at home yourself.

But by far, the cheapest thing to do is to purchase a $200 RODI filter. It sounds like a high price upfront, but you save not only in your first year. I did a video once, and over the course of 5 years, you save thousands of dollars. So do yourself a favor and buy an RODI filter day one.

Check out our RO/DI filter gear guide right here.

2. You Only Learn About Saltwater Aquariums By Doing

You can only research so much. I don’t know if you were like me, but when I started out, I read and read and read, and I watched tons of videos. I scoured different forums. Bulk Reef Supply YouTube had started a few years before. I remember watching newyorksteelo. I was inundated with too much information. And at some point, I just had to pull the trigger and start building my tank.

Think about it. If you want to learn to be any sort of professional or good at any sort of hobby, let’s take piano, for example. You can’t just read about how to play the piano. You actually have to sit down and play the piano. It’s the exact same with saltwater aquariums. You can learn a lot and do your due diligence beforehand, but at the end of the day, it’s only that hands-on experience that’s going to make you learn and grow in this hobby.

3. Test 2x Each Week

An often overlooked saltwater aquarium tip for beginners, water testing. Now, I don’t mean you have to test for every single thing. Sure, I want to test for ammonia and nitrite at least twice a week when I’m cycling my tank. But once the tank is cycled, I don’t really ever test for those things anymore.

So then what do I mean by test twice a week? I would test for your alkalinity, your nitrate, and your phosphate twice a week. I would do this probably at least for the first 6 months after starting up a new system. You’re going to notice that there are all sorts of swings in your tank, little mistakes you make, coral growth, something dies, and it’s going to set things off. And the best thing you can do is catch a swing early so that you can do something like a large water change to get ahead of any problems.

Here are the Bulk Reef Supply recommended water parameters, and click here to read the full blog article.

And be sure to check out our favorite test kit gear guides.

product picture of hanna instruments blue colored alkalinity checker on a white background. Bright blue plastic oval with a large led screen in the middle with a current reading of 10 dkh.
Product shot of oval shaped purple Hanna Nitrate HR Checker on white background. LED screen in the center reads 15.0
ultra low range hanna colorometer, green on white background with PO4 reading of 0.5 ppm

4. Use a PAR Meter... An Often Overlooked Beginner Saltwater Aquarium Tip

I’m not saying you have to go out and buy a PAR meter because that is an expensive thing for a lot of people, and not a very good beginner saltwater aquarium tip! So you really have one of two options. One is to borrow a PAR meter. Your local club probably has one. You might be able to rent one from your local fish store. But knowing the exact output of your lights is crucial. And you only have to do this once.

We honestly can’t tell if something is low PAR or high PAR because our eyes don’t see certain wavelengths of blue very well, and blue packs a punch.

So you have one of two options. One, you can buy a light and follow instructions that somebody else has done so that you are matching their settings exactly and you’ll know their PAR. Or whatever light you get, either purchase, rent, or buy a PAR meter. Set it up right the first time, and then you can forget about your lights. 

5. Start With the End Goal: What's Your Dream Saltwater Aquarium?

What do you want out of a tank? I have said this for years now, going back over a decade of making videos on YouTube, but you need to know what your end goal is.

If you want something like a small, HelloReef tank, 15 gallons, that’s going to be something completely different than a 300-gallon behemoth that you want to put some baby shark into.

You need to know your goal so that you can build a tank appropriately. For me, I’ve built a ton of tanks in my life, and I’ve tried a whole bunch of different things, but the most satisfying for me at this stage in the hobby is something small, around the 15-gallon size.

So know your goal first, and then you can go about doing the research you need to succeed.

6. Feed Frozen Food... Not Pellets. Biggest Beginner Mistake

I don’t mean only feed frozen food, but if you’re choosing between frozen food and pellet food, do the majority of your feeding with frozen food. It’s really high in protein, doesn’t have fillers, and won’t pollute your tank nearly as much.

If you primarily feed pellets, they are super nutrient dense and, especially for beginners, really easy to overfeed. But if you use frozen food, something like Hikari Mysis Shrimp, it is way more difficult to overfeed.

Check out our fish food gear guide if you want to see some of our favorites.

So at the end of the day, favor frozen food over pellet food. And of course add in whatever other foods your animals need, some algae wafers, nori, shrimp pellets… you get the idea.


7. Don't Give Up. Beginner's Usually Don't Make it a Year

It’s really the only way to fail in this hobby, and I mean that.I think I’ve set up 15 to 20 tanks in the past decade, and many of them have completely failed.

My first tank was a Red Sea Reefer 170, and it failed because I ran way too much GFO, which was a big thing over a decade ago. My second tank failed because I just got lazy with it. I let it get taken over by nuisance algae and then didn’t put in the work to care for it.

There are various reasons our tanks fail, and you have to be gentle with yourself because you’re a beginner, and you’re not going to get everything right the first time. But when you fail, if you take it as a learning opportunity and then learn and grow and get better at this hobby, fantastic.

But if you fail and say, “I suck, this is not for me, I can’t do this hobby,” and you quit, well, that’s the only time that you failed. So don’t give up, and you’ll never fail in this hobby.

iphone photo of a saltwater aquarium reef tank. There are a few corals inside with some purple looking algae covering a white sandbed. The point of this image is to show a tank that failed.
My first tank, the Red Sea Reefer 170

8. Do A 20% Weekly Water Change: The Most Important Beginner Tip

I know there are people out there who are intermediate to advanced hobbyists who don’t do water changes. But let me tell you, that is not for beginners for a whole host of reasons.

I’ve also said in the past that doing a 10% weekly water change is great, and absolutely, a 10% weekly water change is great. With a weekly 10% water change, the maximum amount of pollutants you can add is limited to 10x.  Check out this chart from Hamzas Reef

If I add 0.1 ppm phosphate to my tank each week while doing weekly 10% water changes, I max out high much phosphate can ever get into my tank at 10x that amount, so 1.0 ppm. And if I don’t do a weekly water change, those phosphates would keep going up and up.

But if you do a 20% weekly water change, especially if you have something small like a 15-gallon system, that’s only three gallons a week. Really easy to accomplish, and you are going to have so much more success.

I’ve actually gone further than 20% a week, and on this HelloReef tank here, I do five gallons a week, which is probably somewhere around 40%. I do this because I’ve been overfeeding a little bit, and my nitrates and phosphates have been creeping up. So rather than deal with things like GFO or carbon dosing, just do a larger water change once a week. It’s not that expensive, your animals are going to love it, and it’s going to stop a lot of problems from even starting.

If you decide to do a large water changes like me, it’s super important that the freshly made seawater is the same temperature as your tank.  That way you don’t shock your animals!

9. Get Two Heaters and a Temperature Controller

I don’t mean you have to go out and get some sort of fancy aquarium controller. I’m talking about a temperature controller, either something from Inkbird or Bayite. These can range anywhere from $30 to $60, give or take. Here’s our temperature controller recommendations.

Now, why two heaters? Well, you’re going to have one that is plugged into your temperature controller. That’s going to be your primary heater that keeps your tank from 77 to 78 degrees.

But at some point, that heater will die. It might be five years, might be 10 years, might be two years. I don’t know. I’ve had good luck with heaters, and mine have lasted for many, many years. But when that heater dies, you want that second heater to kick on before the tank gets too cold.

So that first heater you plug into the temperature controller keeps your tank 77 to 78 degrees. When that heater eventually dies, you’ve had a second heater sitting in there set to 74 or 75 degrees that will automatically kick on and save your tank. Here’s our heater gear guide.

And you’ll know when that happens because your temperature controller has an alarm on it. So you can set it to go off at 75 or 76 degrees, knowing that your primary heater is broken and it’s time to take your secondary heater, move it to the primary position, and buy a new heater to act as backup.

a product shot of the inkbird temperature controller. It is a rectangular unit with three parts. The first is the controller itself with a grey plastic body and rectangular shape, two lcd display screens and control buttons. Then there is a black rubberized temperature probe. And finally there is a separate portion with two three pronged outlets, both for heaters
A product shot on a white background of three different sized aquael ceramic heaters. Each one is made of black plastic, has a suction cup on the back, and a control dial near the top with led lights that show the temperature.

10. Stick to the Basics and Learn As You Go

Here’s what I mean by this. Don’t go out and buy every piece of gear you might need someday.

It’s really easy to do something like over-filter your water if you have multiple filter socks, a fleece roller mat, a macroalgae refugium, an oversized protein skimmer, an algae scrubber, ozone reactor, and a UV sterilizer. If you have all of these things and you put them in your tank day one, you’re going to over clean the water, and that’s going to spell disaster for corals.

Your fish are going to be fine with that, but your corals are absolutely not. Rather, start simple. You don’t need anything fancy. Start with simple filtration like a sponge or filter sock. Then, as you grow in this hobby, as your tank matures, as you water test and you find the areas where your tank is lacking, then you can add in filtration as needed.

Maybe it’ll be time for a protein skimmer, or maybe the best bet is going to be adding some sort of copepod refugium. You’ll figure that out as you go along. Just don’t add it all at the beginning. So stick to the basics, don’t overdo it at the beginning, and only tackle problems as your tank matures.

11. Buy DC Pumps & Wavemakers. AC Pumps Vibrate Annoyingly

DC pumps cost more than AC pumps. In most tanks, you are going to have both a return pump and a wavemaker. You might have some other pumps in there as well, but those are the primary ones and the ones that are going to be on all the time.

When you’re new to the hobby, the buzzing from AC pumps may not bother you, but as soon as you switch to a DC pump and it runs completely silently, it’s going to blow your mind because it’s just so much nicer.

Not only are DC pumps virtually silent, but they’re also controllable. And having a controllable pump is super handy for adjusting the flow, to getting it just where you want it, or for creating randomness in your aquarium, which is great for your anemones and corals.

Here’s our Wavemaker Gear Guide and here’s our Return Pump Gear Guide.

close up product shot of aquaillumination nero wavemaker. It has a black case body, and green propellers. It's on a white background, with swirling water around it to simulate water movement
AI Nero DC Wavemaker
product shot of the white and red reef octopus varios dc return pump with the rectangular white controller.
Reef Octopus VarioS DC Pump

12. Pick One Source of Information

Pick one source of information and stick with it. Be sure the source you choose shows both their successes and their failures. Nobody is perfect in this hobby, and if somebody tries to convince you that they are, it’s probably good to stay away from them because they’re either miraculous or they’re not being completely honest with you.

The problem with consuming too much information is different recipes can’t be mixed and matched easily. Imagine making cookies. You could find 10 different recipes and then combine those 10 recipes together, and you’re going to get a really crappy cookie. Each recipe by itself would likely make a good cookie, but you can’t mix them all together.

It’s very similar to that in this hobby. There are many, many ways to build and maintain a successful saltwater aquarium. Just don’t go mixing and matching and putting them together because it’s probably not going to work.

Rather, find a good source of information, whether that’s My First Fish Tank, whether that’s Bulk Reef Supply, whether that’s someone on a forum, and stick with it. Then once you get your feet wet in this hobby, then you can put out your feelers to other sources to help advise you and grow your knowledge in this hobby.

13. Use a Mesh Screen or Lid

Typically when we’re talking about a screen, we’re talking about some sort of mesh. It allows for good air and gas exchange between the surface and the air, but it’s also going to evaporate quite a bit of water from your tank.

Whereas if you use a glass lid, you will cut down a lot on evaporation, but the tank will retain more heat.

Using a screen or a lid is just good practice to protect your fish. There are a ton of fish that are known jumpers: gobies and wrasses to name a couple, but there are other fish that aren’t known jumpers that will sometimes jump if they’re scared. Here’s a primer on beginner saltwater fish.

For example, I had this clownfish in one of my tanks for many years.  No lid, no mesh screen, and no problem.  One day I can’t find her, and sure enough, she jumped and was dead on the floor. It was awful.

So do yourself a favor, get a lid, a mesh screen, build one for yourself, have someone make it for you so that it looks nice, cuts down on evaporation a little bit, and also makes your fish safe.

close up of a corner of a clear mesh screen with black plastic rim sitting on top of a tank filled with water
IM Mesh Screen

14. Get What You Want the First Time

What do I mean by that? If you know and have your heart set on a 120-gallon mixed reef system, but it’s just out of your price range right now, rather than buying something smaller, save up for it and get what you want the first time.

That’s not universally good advice. If you know it’s going to take you years to get there and you have a good deal on something small, yeah, absolutely, go ahead and get that smaller system because there’s a lot to learn and a lot of joy to be taken from a smaller system.

But if you know there’s only one reason you want to get into this hobby, one type of pet or animal that you absolutely have to have, then just be a little patient, save up your money, and get the gear you need the first time.

Check out our saltwater aquarium build lists at all different price points and sizes.

15. Use a UV Sterilizer

I don’t know if this one’s controversial or not, but I’m going to say it anyways!

Some people will say it’s completely unnecessary, and they may absolutely be right, but I just know this: when I’ve used a UV sterilizer on a system, I’ve had way more success than when I have not.  Of course it’s just anecdotal evidence, but I’m convinced.

There are some really good UV sterilizers out there in an 8-watt or a 15-watt size that don’t need fancy plumbing. Yeah, I have some bigger UV sterilizers that can be plumbed into your larger tanks, but there are some really cool ones from Aqua UV that are hang on the back UV sterilizers. Literally, you hang it on the side, you add a pump, and you are now UV sterilizing your small tank.

So again, I don’t know if it’s just chance, but I would recommend getting a UV sterilizer. It will help cut down on all sorts of bad things in your tank, help your fish thrive, and maybe avoid some of the nasties like dinoflagellates.

product shot of small black hang on the back Aqua UV sterilizer on white backdrop
Aqua UV HOB Sterilizer

16. Use Velcro Cable Ties

Our final beginner saltwater aquarium tip… I learned this the hard way. Wire management, of course, is absolutely crucial. You’ll be shocked and dismayed with how many different cables it takes to run a small system. So in the past, I had used normal cable ties to keep my wires secured and cinched together.

But then you have to do one thing, maybe you have to change a heater out, maybe you need to clean a pump, and the only way to do that is to pull it off of your system and take it to the sink. But then you have to go through and cut all those cable ties.

And not only that, but I have hurt myself. I’ve had deep gouges in my skin from cable ties that I hadn’t cut perfectly.

Velcro cable ties are the answer. I buy huge packs of them and use them all around the house. Using Velcro cable ties not only will save your arms from getting cut, but they will allow you to make changes and do maintenance on your gear easily and whenever you need it.

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