Algae Scrubber Basics

[Floyd R Turbo]

The Darice #7 Mesh plastic canvas is actually Linear low-density polyethylene (LLDPE) and while I have had a screen deteriorate over time, it took well over 2.5 years and it was mainly due to aggressive scraping, combined with having 2 Royal Blues on opposing sides at full strength.

LED scrubbers have little if any UV component. Time has shown that even T5HO and CFL scrubbers (which have a UV component) do not deteriorate screens, at least, not noticeably. I'm sure that many can attest to this.

 

[Spar]

Bud, any thoughts as to what type of water the mortar-added sheet should be soaked in?

I am currently soaking it in RO/DI since it will have the most absorption ability.

 

[Floyd R Turbo]

tap water would probably be OK but RODI would probably be better as it would suck more out, or just do it faster

 

[Floyd R Turbo]

Floyd,
above you say that it is better to start the scrubber from day 1 in a new DT, I am just a little worried that if I run it from day 1, the scrubber will consume most available N and P from water, so to lower the capacity of scrubber I could run it from day 1 at a flow of 20GPH / inch and only light the screen 6 hours??

do you think this is a good idea? please tell me what you think

You can do that, but is there a particular reason why you don't want the scrubber to keep N and P down?

how much time does a new ATS needs to be running to go through the initial steps and be ready to work at full capacity?

Depends on the system. Typically this has been 4-6 weeks usually. With the mortar screen method, this might change. I haven't seen this in action personally and since it's relatively new, count on 4-6 weeks until results come in and are consistent. As with everything new, there might be a right way to make them, and a wrong way (or maybe just a "that'll do" way and a "best" way)

 

[Spar]

I will be running my scrubber off of a manifold coming from one my return pumps. I currently have a 3/4" nipple coming off of it. I however made the 8" slot out of 1" PVC. Am I better off changing to a 1" nipple coming off of the manifold, or will attaching 3/4" tubing to 1" PVC be just fine as long as I am pushing through the required GPH?

It will just be a pain in the rear to get the new nipple put on, but can if necessary/better.

 

[Floyd R Turbo]

should be fine, you will get a bit of head loss which will reduce flow through the 3/4" section but you should be able to adjust things to make it work.

 

[jason2459]

There's a lot of species of Cladophora
http://www.algaebase.org/search/species/

Is there a specific type of types that are more common in our aquariums ?

Here's what mine has been turning into

Kind of reminds me of chaeto.

 

[sporazoa]

So you guys are discovering that an algae scrubber is more efficient at removing phosphates from the water column than a sump/fuge with chaeto or other fuge algae?

Why does it have to be suspended & why not just submerged? Isn't it the same algae that grows on our rocks & fuge & comes in from reef plugs & coral rocks?

 

[karimwassef]

I have a fuge and I use it primarily to cultivate pods. The chaeto is ok but it is susceptible to acting like a mechanical filter and trapping waste that results in a cyano bloom (in the sump only) over the chaeto.

Maybe I wasn't pruning it often enough, but I'm experimenting with a scrubber primarily to avoid the cyano on the chaeto.

 

[Spar]

Algae Scrubber Basics

So you guys are discovering that an algae scrubber is more efficient at removing phosphates from the water column than a sump/fuge with chaeto or other fuge algae?

Why does it have to be suspended & why not just submerged? Isn't it the same algae that grows on our rocks & fuge & comes in from reef plugs & coral rocks?

Copied from the other post has a great answer to that. Basically saying that exposure to air is much more efficient and effective. See below:

The combination of very high lighting and the air/water interface of the waterfall method making an extreme abundance of CO2 available for the algae greatly promotes its growth.

The screen also allows air to pass through it to keep the base algae alive and maximises available lighting surface area.

The CO2 content under water is much less so the algae will preferentially grow on the screen.

 

[mattberrytr]

I don't think it has been proven that waterfall scrubbers are so effective because the algae growth is pulling CO2 from the air. Personally I don't think this happens for any scrubber method - be it upflow, waterfall or even most surge scrubbers. The algae would have to be exposed to the air for a while before it's dry enough to absorb any CO2. It's much more likely, IMO, that the speed at which the water is flowing over the algae growth is allowing more nutrients to be absorbed by the algae.

When scrubbers operate submerged, they are usually in a sump, or an area of much lower flow. Even in a sump that has very high flow running through it, it's likely that the flow rate very close to the algae (which is what is important) is significantly slower than what it would be on a waterfall scrubber. Turbulence is great for algae growth, and you get this from a waterfall scrubber.

 

[sporazoa]

I would also imagine that all depending on what type of algae takes hold, that for some it is more beneficial than others. Some algae are probably better at removing phosphates than others.

I also have an idea for a BETTER system of filtration that I encountered by accident already twice by coming in & out of the hobby. The last time I heard another reefer talk about it & the big AHA moment clicked at what was happening & why. I am going to write up a thread on this & you guys let me know what you think. I will like the thread once I am done posting it.

 

[sporazoa]

Here is the link to the thread I started. LMK what you think?

http://reefcentral.com/forums/showthread.php?p=24103677#post24103677

 

[herring_fish]

I don't think it has been proven that waterfall scrubbers are so effective because the algae growth is pulling CO2 from the air. Personally I don't think this happens for any scrubber method - be it upflow, waterfall or even most surge scrubbers. The algae would have to be exposed to the air for a while before it's dry enough to absorb any CO2. It's much more likely, IMO, that the speed at which the water is flowing over the algae growth is allowing more nutrients to be absorbed by the algae.

When scrubbers operate submerged, they are usually in a sump, or an area of much lower flow. Even in a sump that has very high flow running through it, it's likely that the flow rate very close to the algae (which is what is important) is significantly slower than what it would be on a waterfall scrubber. Turbulence is great for algae growth, and you get this from a waterfall scrubber.

I have to agree.
We are not talking about the underside of a tree leaf. Algae is adapted to absorb CO2 most efficiently via direct water to cell contact, not through air to cell contact. In nature, algal growth is strongest at the water line that stays submerged throughout the tidal cycle, not at the line that is out of the water part of the day or with intermittent splashing. This is also born out in the lab.

Regardless of the design, water flow, stable 3-D, static horizontal, UF or dump bucket, water to cell wall contact is more efficient than air to cell wall contact. This has been proven time and time again.
If you go to a planted fresh water forum, you will find that injecting CO2 can improve growth only if it is fully dissolved into the water column. Injecting bubbles or providing exposure to air is not as efficient as getting more water to the cell walls. Within certain limits, if you have more water flow, you have more water to cell wall contact so you get more growth.

 

[hkgar]

I will be running my scrubber off of a manifold coming from one my return pumps. I currently have a 3/4" nipple coming off of it. I however made the 8" slot out of 1" PVC. Am I better off changing to a 1" nipple coming off of the manifold, or will attaching 3/4" tubing to 1" PVC be just fine as long as I am pushing through the required GPH?

It will just be a pain in the rear to get the new nipple put on, but can if necessary/better.

I also run mine off a manifold from my return pump. I would suggest that you install, in this order from the return, a ball valve and a gate valve. I adjust the flow with the gate valve and use the ball valve to shut flow off for cleaning. That way the GPH doesn't have to readjusted after cleaning. I use 3/4 inch pvc for the screen because Floyd has a piece that will fit over 3/4 to prevent the algae from growing up into the slot and interfering with flow.

 

[Spar]

I also run mine off a manifold from my return pump. I would suggest that you install, in this order from the return, a ball valve and a gate valve. I adjust the flow with the gate valve and use the ball valve to shut flow off for cleaning. That way the GPH doesn't have to readjusted after cleaning. I use 3/4 inch pvc for the screen because Floyd has a piece that will fit over 3/4 to prevent the algae from growing up into the slot and interfering with flow.

i just hate how bulky gate valves are. is it not very easy to regulate gph from a ball valve, since you really just need an approximate flow, not an exact (i.e. 35-50gph per sq/in)?

 

[hkgar]

Ball valves are, IMHO, difficult at best to regulate, just not a lot of wiggle room and often difficult to start turning and that tends to over open or close them when trying any kind of fine adjustment.

 

[Spar]

i want to get my ATS up and running when my rock comes in on Friday. however, I will not be getting my LED's for a couple/few more weeks.

i will/can buy CFL's in the mean time, but really only care to have one reflector/bulb on each side to not overdo the equipment since I will soon be replacing it (no longer needed).

Question is: the write-up says 1 watt CFL per square inch; I will have an 8x8 screen (64 sq/in). Is the 1 watt for per side, or in total. If per side that would be ~3 23w bulbs on each side, taking up a ton of space. I am hoping that I can just get away with 1x 23w bulb on each side while the screen is in the breakin period anyway.

Thoughts?

 

[Spar]

Ball valves are, IMHO, difficult at best to regulate, just not a lot of wiggle room and often difficult to start turning and that tends to over open or close them when trying any kind of fine adjustment.

ya good point. hence why i/we (generally) use gate valves on beananimal drains. i am picking up parts today so will grab a gate valve and ball valve. union as well. worth the extra cost to not have to deal with issues later IMO/E.

 

[Floyd R Turbo]

Question is: the write-up says 1 watt CFL per square inch; I will have an 8x8 screen (64 sq/in). Is the 1 watt for per side, or in total. If per side that would be ~3 23w bulbs on each side, taking up a ton of space. I am hoping that I can just get away with 1x 23w bulb on each side while the screen is in the breakin period anyway.

Thoughts?

For the initial break in period, don't worry much about the intensity, you just want to get light on the screen, and about any light will do really.

the rule of thumb for CFL is you want (minimum) the same total light on the screen as the LxW. So for 8x8=64, 64w total, or 32W per side, for 18 hours/day.

For "high intensity" CFL you would double that, and halve the hours (64W per side for 9 hours) but if you did this initially, you would cook the screen probably (photosaturation). Besides, you're looking at temporary lighting anyways.

I would just do a 23-26W 2700-3000K CFL in an 8 or 10" dome reflector on each side