UV sterilizer dual use schedule for pathogens and algae

[blackstallion]

An UV will clarify algae/bacteria at sterilization levels certainly, you just need to be moving 2-3 times the tank volume through the unit per hour. I’m using the TMC 110 which recommends 10 gallons per watt per hour for level 1 sterilization, so 1,100 GPH. That means 2.75 for my 400 gallons. For 200 gallons, I’d view 55 watts as ideal to run 550 gph. Also keep in mind that most 200 gallon tanks don’t actually hold 200 gallons so that gives you some wiggle room.

I haven't heard of TMC up until now, probably because it's not sold in the major reefing websites as TMC seems to be targetted towards ponds. Looks like the TMC 55W is going for $300, which is an excellent price wrt the other major brands. What are the trade offs to the $450-$700 models in the same 55w'ish rating? Or is it more along the lines of reefers willing to pay out the nose for products targetting their specific hobby/application?

https://www.americanaquariumproducts.com/TMCUVSterilizer.html#cart

 

[ca1ore]

Well, the TMC110 was recommended to me by a local reefer that uses one. Build quality is excellent and the price is much more in line with what I wanted to pay for a PVC housing, ballast, a few end caps and bulbs LOL. Only downside is that it is physically quite large. Sorry to say I have no experience with the 55 .... other than it’s a bit goofy looking. UV is a pretty simple device and I think the branded units in the hobby are overpriced.

Nothing different pond versus aquarium where UV is concerned. Prior to the TMC I was using a pondmaster unit, but it was always blowing ballasts and I just got fed up.

 

[DaddyFish]

I just recently ran the calculations for a 215-gal I'm setting up and decided to upsize the UV from a 40w to a 55w. That gives me enough UV power to kill parasites/protozoans at roughly 3x tank capacity, which is the minimum flow rate I intend to use.
For algae/bacterial sterilization I will increase the flow rate to 12x-15x tank capacity, which I can accomplish either one, using the same loop and a good DC pump.

 

[FishTruck]

I looked into a DC pump to feed a 40W sterilizer and it recommends 157gph to kill pathogens and 943gph for bacteria/algae; couldn't really find anything that could be regulated in that flow range.

Would a ball (or other) valve be advisable in conjunction with either an AC or DC pump to regulate the flow?

The use of a valve only works if you can measure the flow. The nice thing about a DC pump is no need for that, you just have to trust the specs on the pump.

 

[ID-Reefer]

Run two Vecton 600s in line. Pull and return water directly to display tank. Use the Neptune COR-15 pump externally. Runs 24/7 Have it set at 80% (450 GPH with head pressure) for 18 hrs a day for protozoan and 6 hours a day at 100% for more tank turnover and algae. Working great so far.

 

[blackstallion]

The use of a valve only works if you can measure the flow. The nice thing about a DC pump is no need for that, you just have to trust the specs on the pump.

I think even with DC pumps there are variables that are difficult to account for, like head pressure, plumbing length, etc. that would benefit from a rudimentary characterization of the flow. Basically measure how long it takes to fill a gallon, or even couple of gallons of water into a container and then calculate gph from that.

 

[Traveler]

That would work if you had a big enough (oversized for your tank) UV. But algae and bacteria multiply very fast. If you have 100 GPH going through your high-contact-time UV and a 400G system with cyano multiplying like it's Mardi Gras, they're going to replicate faster than the UV can treat them.

The fast flow/low contact time lets you treat more water with a less expensive light and lower electricity costs if you only care about treating certain types of pests.

So assuming my estimate of 200g, what size UV would you recommend as oversized that could be run at the pathogen sterilization rate and also be effective for bacteria/algae? I've been looking into the 40w range UV which is spec'd to about 260g (Pentair).

IMO a way to look at this is not by tank size, but by flow rate into the sterilizer and how many times at that rate will you turnover the volume of the tank. To sterilize at 180K uw/cm^2 according to Pentair you need 157 gph min to 262 gph max flow thru the sterilizer. Any faster with that unit it will not have the same effect. Which is approximately 4 to 7 gph/watt. To affect algae, Pentair uses 30K uw/cm^2, 1/6 of of the uw/cm^2 required at the slower speed or approx 6X the UV power needed to affect algae, using the slower rate. I am assuming you are pumping more than 262 gph to turnover your tank at least 2x per hour. If so, as previous poster offered, 50 - 55 Watts, (using 10gph/watt) may be another option. I've found the Info on the AAP website regarding sterilizer rates etc, is in line with the other major manufacturers but presented in a simpler form, (i.e. 10 gph to achieve Level 2 sterilization, 30 - 35 gph/watt for level 1).

 

[User]

So- higher flow giving around 30-40K per cm2 is good for the reef environment, and lower flow (more contact time) around 70-90k is good for pathogens.

what do people do if they are dosing phytoplankton? Just turn off the UV for that period of time? What if you are continuously dosing? SOL?

but now I verbalized that- if your aim is to clarify the water, you wouldn’t be intentionally dosing phyto anyway, right?

Im looking at a 57w minus bulb for $200 on a local site. That’s 1/3rd retail, 1/2 retail when I factor in the bulb.

I suspect I might have some amphodinium and would be looking to put 1000g/h through it for a 5x system volume (220g) turnover per hour .