Algae Scrubber Basics

[kegogut]

And upon further inspection,I turned the flow off for a minute and it looks like Im getting some pretty decent growth on my screen . I also decided to test my No3 and its down to between 5-10,it was 20 when I measured it 12 days ago. This is also with an API. I was using Salifert but I ran out. =x
I'll use the API until it runs out (which shouldnt be long) and buy some more Salifert kits.

 

[Floyd R Turbo]

Algae Scrubber Basics

API phos kit is pretty much worthless for differentiating between anything lower than 0.25 IMO. Best to use a Hanna checker. Standard phosphate is fine. Ultra low range requires additional steps to get accurate readings (rotation of vial is important)

Salifert for nitrate and potassium

 

[kegogut]

I use Salifert for No3,calc,and mag. I was using the API phos until it ran out but my reef club has a Hanna Phos meter I'll grab to test with.

 

[WhiteShark1]

Im definitely interested in these bulbs too. Right now Im running four 23w 65k CFLs 20 hours a day. If these are good then I would like to try two of these instead of the four CFLs.
Last time I cleaned my screen I think I cleaned it too good and set myself back a few weeks. so we'll have to see what happens in a couple weeks.

I do have a question though. Right now Im reading at 20 No3 and 0 Po4. Would having low Po4 slow my growth of algae ?

I am finally starting to get some growth with these bulbs, right now I'm just at the brown algae stage with a few strands of green hair algae, but I'll keep you guys updated.

 

[Hawg Pharm]

One thing I've noticed two months in is how easy it is to maintain pH levels. I used to struggle to get it to 8.00 but now easily keep it around 8.30.

 

[kegogut]

One thing I've noticed two months in is how easy it is to maintain pH levels. I used to struggle to get it to 8.00 but now easily keep it around 8.30.

Where is your sump? Usually PH lvls will drop a bit in winter because your furnace is on more and raises the carbon monoxide lvls which in turn lowers Ph lvls.

My sump is in the basement next to my hot water heater and furnace. I had to run my skimmer's air line outside my house to maintain Ph lvls above 8. I was around 7.9 before I ran the air hose which isnt bad really. Ive seen absolutely stunning tanks that kept ph between 7.8-7.9

 

[salty joe]

Where is your sump? Usually PH lvls will drop a bit in winter because your furnace is on more and raises the carbon monoxide lvls which in turn lowers Ph lvls.

My sump is in the basement next to my hot water heater and furnace. I had to run my skimmer's air line outside my house to maintain Ph lvls above 8. I was around 7.9 before I ran the air hose which isnt bad really. Ive seen absolutely stunning tanks that kept ph between 7.8-7.9

Neither your water heater nor your furnace should cause a drop in your tank's PH. It might be wise to find the leak in the exhaust. If that appliance starts burning gas poorly, you will get CO in your house instead of CO2. Exact thing happened to me a few years ago. Squirrels made a nest in the water tank flue. I was able to tell the wife, "see, the tank keeps us safe!"

 

[SantaMonica]

Any extra CO2 dissolving into the water would be welcomed by the scrubber.

 

[salty joe]

Which is why I plan to put the effluent from my calcium reactor in front of the algae scrubber.

Do you have any experience using CO2?

 

[Floyd R Turbo]

Brummie (Garf) is the man to ask about that.

 

[Brummie]

Algae Scrubber Basics

Brummie (Garf) is the man to ask about that.

Oh yeah bud - had loads of sleepless nights with my CO2 experiments. I got double the growth mass such that my waterfall would bend under the weight, and Stoichiometry would suggest that double nutrients were contained in biomass. A fully automated system would undoubtedly increase yeild.

Edit - I would add that CO2 takes 21 seconds (from memory) to hydrolyse
to carbonic acid, so bubbles are useless in this case. Any bubbles need to be in contact with the water for over 21 seconds for any benefit through CO2 enrichment, as far as I can tell.

So yep, a calcium reactor ticks all the boxes

 

[salty joe]

Well then, I guess no need for a second chamber on the calcium reactor-just let the algae eat all the CO2.
Thanks guys!

 

[hkgar]

Jumping in. Considering building an ATS.

First question is regarding the flow rate over the screen. My system calculates out to about 195 gallons and I would get a screen 14x14 (196 sq inches). That means I need a flow over the screen of 490 gph? Just seems like pretty high flow. a maxijet 1200 won't due it. A mag 5 looks to be about the lowest price pump that would work.

My sump is in the basement and I am using an Iwaki 100 as the return because fo high head pressure. It is pumping at about 790 gph. I might consider taping into the return line, but I get a lot of bubbles coming through the return line.

Any thought or ideas for me?

 

[salty joe]

I don't think bubbles will hurt a thing.

 

[JohnnyB in SD]

I don't think bubbles will hurt a thing.

x2 bubbles don't matter
Tap off the return

 

[Floyd R Turbo]

Jumping in. Considering building an ATS.

First question is regarding the flow rate over the screen. My system calculates out to about 195 gallons and I would get a screen 14x14 (196 sq inches). That means I need a flow over the screen of 490 gph? Just seems like pretty high flow. a maxijet 1200 won't due it. A mag 5 looks to be about the lowest price pump that would work.

Screen flow is 35 GPH/in of width, area doesn't factor in. So 14 x 35 = 490 GPH, give or take.

But, scrubbers are not based on volume anymore, they are based on feeding. 12 sq in of screen, lit on both sides, per cube of food fed per day (average). So unless you are feeding 196/12 = 16 cubes/day, it's way too big.

MJ1200s are bad for scrubbers in general, not enough head pressure (it drops off really fast with any growth)

So recalculate based on feeding to get area, then figure up what W x H you would need, then W x 35 = flow. Flow needs to be after all head losses. Use 24" equivalent head for the slot pipe, then add vertical rise, and this will get you close to the pump you need at that given head loss.

My sump is in the basement and I am using an Iwaki 100 as the return because fo high head pressure. It is pumping at about 790 gph. I might consider taping into the return line, but I get a lot of bubbles coming through the return line.

Any thought or ideas for me?

Bubbles in the feed line to the scrubber won't hurt the scrubber at all

 

[SantaMonica]

Finally, someone makes a clip-on grow light:
http://www.ebay.com/itm/161252647371

 

[Floyd R Turbo]

Nice

 

[JohnnyB in SD]

x2 bubbles don't matter
Tap off the return

Just to be clear, what I meant is tap off the return from the tank drain to the sump, not the pump to the tank, if your setup allows it. Add a ball valve to adjust flow on the siphon drain and run it through the ATS, which should have a fair amount of flow and pressure if all that 790gph is going through one overflow / drain system. Certainly enough to hit 490gph.
I feed 2 @ 18" wide ATS, one from each siphon drain on the corners of my display. The ball valves are usually wide open. If there is any backup of water from the ATS on the siphon drain, it flows through the open channel drain and I don't notice if it even happens.
This method does not divert any flow from the return pump to the tank, and does not require adding a pump.

 

[Floyd R Turbo]

ah. you mean overflow-fed, not return fed. When I think return fed, I think return pump. Not return from DT to sump, that's overflow or 'drain' fed.

yes if you are talking about tapping off the siphon line, that's fine. I know others have done this and it works. I believe (others who have done it, correct me if I am wrong) is that you would want 2 things: the standard siphon control valve, and a ball valve for shutting off the scrubber for maintenance.

You would normally leave the shutoff valve all the way open. Place the siphon control valve below the point where you tee off to the scrubber. Then close the siphon valve until you get the flow rate you want through the scrubber.