Uv flow regarding tank sizes

[Reef46]

So I have a 20 gallon long bb mixed reef. I run a bullet hob skimmer and two nero 3 pumps. Alk is 7.5 cal is 419 mag is 1320. I bottomed out on n03 and p04 due to starting with dry rock. I currently dose both to get in range. N03 is currently 4.0 and p03 is .03. All checked with Hannah checkers. Also confirmed with recent trident icp. The dinos are driving me crazy. Never dealt with them like this as ive always started with good live rock. Been reefkeeping for well over 25 years. I got a sicce uv 13 watt with the syncra silent 1.5 pump with max flow of 357gph. I have it turned all the way down so im not sure exact on gph. My main question is why would flow rate matter on tank size? Isn't 357gph the same on a 20 gallon as it is on a 200 gallon as far as effectively killing the dino spores? I see recommendations of 2 to 3 times the tank volume per hour for flow but that's drastically different depending on tank size. So not being the sharpest blade in the box with some things I am kinda stumped. If the uv has 357gph going through it and is fine on a big tank why is it too much on a smaller one? Lol. Sorry for the long rant for a simple and short question. I also run a kessil ap9x for 12hrs a day and tank is about 3mos old. I havent got a microscope so dont know exact species of dino. Any help or answer is appreciated. Thanks team.

 

[slogan315]

The flow rate is determined based the uv specs and what you’re targeting, independent of tank size. “This amount of water needs to stay in contact with this UV for that long to be effective against a particular pest”.

The turnover rate is not a perfect science. If not enough turnover rate, then whatever you’re targeting may reproduce faster than you’re killing/sterilizing it. So the uv is rated for a particular range of flow rate, and you have to make sure your tank’s water will turnover enough to make sure it treats your target pest.

To answer your question, I don’t see why you couldn’t use a larger uv on a small tank. Avoiding the topic of, “to UV or not to UV”, it would just be not cost effective and might input too much heat to your system. Last time is sized a uv, I ended up with a 25w for my ~80g tank. Sized it so that it would handle anything for my volume.

Can’t help with your Dinos issues though. I’ve had 99 problems but dinos ain’t 1.

 

[Reef46]

Thanks. I was just kinda scratching my head regarding flow rates and being too much or too little. Regardless of tank size i assumed that flow is processing the same amount of water no matter the tank size. Maybe im needing to think more along the lines of wattage of the uv and if the flow is too fast for the strength of the bulb. It's hooked up and running now so ill likely see results or lack thereof. Appreciate the response.

 

[Quietman]

I noticed with my dinos that once I had the UV on (AquaUV 15 w on a RSR 170) and kept the flow fairly high (about 7-8x turnover) piped through the return (not ideal but it's a small tank) my dino disappeared. After a few months I turned my return flow down to my normal 3x and my dinos reappeared. Kept the flow high for a couple years after that. Well, I forget to replace bulb after 15 months and about the 2 year mark the dinos returned. Replaced the bulb and dinos gone again. Gone in the this case means not visible. They're still there...lurking and waiting for my UV to be less than effective. Been about 4 years now if not more. Time flies when you're not dealing with dinos.

 

[Reef46]

I hate em. Dealt with all sorts of nasty stuff through the years. And have probably fought dinos before unknowingly but never in a small tank. They just pop up so fast. When the lights come on they're almost nonexistent but a few hours in and the lights ramp up and then its just bubbles and brown stringy crap. I blow it off and remove as much as possible. Used a green killing machine but it is pretty much useless. Bought this sicce to feel a little more armed for the battle. Hoping it works and if so ill have to find another way to plumb it in the tank because its unsightly as it sits now. Lol. Have lost one mexican turbo snail but that's it. Have emerald crabs and multiple other snails that dont seem effected by the stuff. Threw on a hob filter to run some carbon just in case. Have a couple corals that dont seem happy with this stuff growing over them but no major losses yet.

 

[Quietman]

Feel for you. Been there. It's all in my build thread but to summarize. Basically lost everything fighting dinos and then the aftermath of GHA. Tanks looked good since then off and on but never really as good as it did before the dinos. My recommendation to people now are just to reboot the tank instead of fighting them. It would have cost me less time and money. And I likely would've had a better looking tank for longer with less effort.