What's the dumbest/biggest mistake you made when you first entered the hobby?

[Rick.45cal]

I still do that at least once a month, But just a few gallons on the kitchen floor.

Happens to me everytime I make RO water for making sweet tea! Fortunately I don't live above anyone. It's funny I have yet to make a mess on the floor on account of this reef tank, I've run it a year now without so much as spilling a gallon from the tank, making sweet tea... well that's a whole other story! (For those that don't know, if you use your RO water to make sweet tea, it makes the best tasting sweet tea in the world!

 

[Bradley Crocker]

Within a month of starting our first tank, my wife and I found an ad on-line for somebody taking their system down and was selling live rocks with the corals attached. We went and bought several large pieces of rock. The largest was covered with what appeared to be some great green soft corals. Little did we know that it was a rock that was fully covered with mojano anemones. We did get some other nice pieces of corals, but I'm still battling trying to eradicate the mojanos from the tank some 6-7 months later.

Same here. Except mine was at a lfs, small rock with two mushrooms and about a dozen other "polyps."
Depending on your livestock and other corals, a bristletail filefish will clean those right up.

 

[vertigo01]

Bought the wife a brand spanking new IM 16gal AIO so she could have her very own "Mini Reef". Fast fwd to 11 mths and 27 days later. A week before our 4th of July vacation, I felt something with her tank was wrong as I was filling the ATO with a bit more RODI than usual but didn't see a leak anywhere so kinda let it pass.
Return home on July 6th. As I am backing the 5er into it's spot the wife runs inside to check on the house to be greeted by the smell of ocean and dried salt crystals all over the new hardwood floor I spent my Christmas vacation putting in.
While we were gone, that little tank decided to fully split from the base seam in 1 rear corner and spill it's total 16 gal's, as well as the 10 gal ATO.
Evidently the tank was leaking prior to our vacation. The water was leaking down the stand ( new Ashley Furniture :mad between the shoe molding and flooring and finally ending up under the new flooring.

I will add that ROOMBAS are indispensable little gadget's, as it helped to spread the saltwater all through out the house before returning to it's dock.

As an added bonus, IM declined any warranty as the tank was now past the 1 year mark, by mere day's.

 

[Reeferguy365]

Went from the orbit Marine LED to a new 155 watt light with 3 watt LEDs on my 29 BioCube.... yeah bleached all but 2 of my rainbow chalice. The chalices cost more than the light. live and learn right.

 

[GK3]

When first introduced to the hobby I collected rock and dead coral skeletons ( I live in florida and they dredge rivers a lot so neat stuff comes to shore ) from my yard and placed them in my tank filled with saltwater without any prior preparation. When I came back in my bedroom five minutes later I had a coral snake ( very venomous, ironic name too lol ) swimming back and forth in my tank. It was hiding in one of the rocks... Im a Genius! I knew some about saltwater tank pests but never thought a snake would be one of them lol. Talk about a fiasco trying to get that thing out!

If your tank has a coral snake...does that make it a reef tank or FOWLR? Things to ponder...

 

[mpjmeyer]

If your tank has a coral snake...does that make it a reef tank or FOWLR? Things to ponder...

SOWLR??

 

[chas79]

Turned off my vortech and forgot to check it before turning it on decapitated my tail spot blenny.

 

[Rick.45cal]

Anyone around buy a blue ringed octopus, get bit and live care to share? Because those that didn't sure can't!

 

[Bryce Peterson]

In '94 I had my first saltwater fowler tank. Asked my 22 year old roommate to watch the tank while I went away for the weekend. It was in the 90s out and he left the balcony window open all weekend with the sun shining on the tank. I came home to my tank at 94 degrees. I lost, a Blue Spot Grouper, Mineatus Grouper, Porcupine Puffer, Volitans Lionfish, and a Dragon Moray. Broke my heart. It only took me 20 years to jump back in.

 

[Bryce Peterson]

Anyone around buy a blue ringed octopus, get bit and live care to share? Because those that didn't sure can't!

My lfs used to sell them for $19.99. Absolutely gorgeous creatures. I would have liked one, but, again, IDIOT ROOMMATE.

 

[mpjmeyer]

I thought I would add a mistake I've been making for the past 4 months. Ever since cycling, I've been battling high nitrates. From doing massive water changes, purchasing a media bio pellet reactor, adding snails, scrubbing and vacuumingthe rock and more, this is what I just realized!! I haven't rinsed out the foam block in my sump since I started which I'm pretty turned into a Willy Wonka nitrate factory!! Seriously!! What an obvious source right in front of my eyes!! Hopefully as of yesterday, after a 35 gallon water change and hardcore foam rinsing, the nitrates shall fall, as we are Sparta!!

 

[brandon429]

My biggest mistake as a beginner was caught and corrected by Eric Borneman on the RC website in his forum. I assumed that photosynthetic corals didn't need feeding, due to the photosynthesis. I was shown the taxonomy placement of plantae vs animalia, heterotrophic feeding classifications, and that perception changed. supplemented by photosynthesis, young jedi

 

[Hyde2406]

I as well topped off with salt years ago can't belive I didn't loose anything

 

[Ashish Patel]

My first saltwater tank was a 72 bow tank FOWLR predator tank. My first big mistake was buying fish that would grow way too big for the tank. I had a Panther Grouper, Harlequin Tuskfish, Volitan Lionfish, Longhorn Cowfish, Clown Trigger, Huma Huma Trigger, Niger Trigger, and a Lunar Wrasse.

LOL - this is a rookie mistake we all do regardless of the warning. I too did this back in 2002 when I got my HUGH 55 gallon tank. i added Panther grouper ,Lion fish, clown trigger, koran angel, yellow tang, eel, spiny box puffer.. At the time I knew it was overkill, however, i really thought my tank was large enough. Today I prefer smaller groups of fish and to throw in some drawf angels and tangs for color.

 

[Ashish Patel]

This was my first saltwater tank back in 1997, I was 12 years old. I remember i would clean the bio media with tap water - This was definitely a fatal mistake ! lol.
Most of my fish would die from diseases and I found this very disheartening especially at my age. Success came to me only after I filtered water with DI, added a small skimmer a UV filter. I never had a fish die from the common diseases since 2002. Make sure you do all you can to avoid having your fish get disease.

 

[dsh92056]

Being scared not knowing what to expect with owning a saltwater tank, getting a 14 gallon, then a 55 gallon, then a 60 gallon & a 34 gallon, now wanting at least a 120 gallon. Believe me if you go small just to see how you do and you get the bug you are going to spend a lot of money going up just get what you can afford and how big a tank you can place in your home. Had I known I would have started with 120 gallon.

 

[neverenough]

When I was a kid one of my dad's fish got ich so I did him a solid. I took it out of the tank and applied the ich treatment directly to the affected area. Let's say he didn't last long after being returned to the tank. Oops...

 

[FishLover01]

Haven't had any major mistakes other than having all four of my tanks only 2 inches from the wall. Now, that plays into what kind of equipment I can have. Wished I had placed all the tanks about 4-5 inches from the wall.

 

[ricky5415]

I bought a lion fish and my 3 years pair of clown disappeared.

 

[kingdog22]

Not using RO/DI WATER!!!!!!!