Algae Scrubber Basics

[scolley]

I disagree, these bald spots are from copepods. Besure to clean the screen under tap or RODI water

D*mn! That would be too cool! From our conversation I gather you think these particular 'pods are too small to see? I'm happy to donate to someone with a microscope if so. Heck, I'VE got a decent microscope myself.. but I'm FAR from qualified to discuss (much less identify!) what I'm looking at.

 

[scolley]

I realized that I forgot to post my screen growth pic...

Before I scraped it, I sprayed the screen really good with a 'shower' setting on the hose to clear the diatom algae, saltwater, etc so that I was left only with the GHA...

Well, I - for one - am impressed. :thumbsup: That looks like a byproduct to be sought by all! Thanks for sharing that.

 

[Floyd R Turbo]

I am planning on using both overflow lines. I will not be plumbing it directly to the skimmer. One pipe will just be run to the sump section where the skimmer is, and the other overflow will be directly to the ATS. In theory both overflow lines will have equal amount of flow going through them. I dont plan on taking the skimmer offline. I will be running the same skimmer I am running on my current tank.

Let me know what you think

I will keep asking questions till I get this up and running

Erik

Good, that makes it easy. What I was getting at is that you have yourself set up for a "Herbie" type of overflow. the "Herbie" (2-pipe) and "BeanAnimal" (3-pipe) are ideal for scrubbers because you can push the maximum amount of water through a standpipe that is running at full siphon, and it is also quieter.

You can run it the way you intended, no problem. What I was suggesting is that you take advantage of your design and turn it into a Herbie (or a modified Herbie, I haven't read up on it, but I have read the entire BeanAnimal "Silent and Failsafe Overflow" thread). What you would do is (if you have the room in the box) is insert a downturned elbow into the side feeding the scrubber, and an upturned elbow into the other side. Run the scrubber so that it dumps into the chamber with the skimmer in it, or into a chamber that then runs through the skimmer chamber. Run the line from the upturned elbow to the same location as the scrubber dumps into, or into the skimmer chamber.

What happens is that you get full flow to the scrubber, and the other pipe would just run enough to handle the excess. Ideally, you would not ever get enough flow in the 2nd pipe to cause it to gurgle or siphon. This also would allow for a full blockage anywhere in the primary siphon pipe and the second pipe would take over (and be quite noisy, alerting you). You would want the 2nd pipe to be larger so it would handle the full flow.

Just some food for thought and it's kind of OT anyways, but I figured I would jump in with that in case you hadn't considered it. Since your tank isn't set up, it's easier now to figure this out than later.

Even without the up/down elbows, you still would have the same functionality (safety) but you may have noise from both pipes and you're splitting the flow. If the skimmer is on one side and scrubber on the other, pump in the middle, then I see why you would run them split 50/50.

 

[mistaflicksta]

You can run it the way you intended, no problem. What I was suggesting is that you take advantage of your design and turn it into a Herbie (or a modified Herbie, I haven't read up on it, but I have read the entire BeanAnimal "Silent and Failsafe Overflow" thread). What you would do is (if you have the room in the box) is insert a downturned elbow into the side feeding the scrubber, and an upturned elbow into the other side. Run the scrubber so that it dumps into the chamber with the skimmer in it, or into a chamber that then runs through the skimmer chamber. Run the line from the upturned elbow to the same location as the scrubber dumps into, or into the skimmer chamber.

What happens is that you get full flow to the scrubber, and the other pipe would just run enough to handle the excess. Ideally, you would not ever get enough flow in the 2nd pipe to cause it to gurgle or siphon. This also would allow for a full blockage anywhere in the primary siphon pipe and the second pipe would take over (and be quite noisy, alerting you). You would want the 2nd pipe to be larger so it would handle the full flow.

Just some food for thought and it's kind of OT anyways, but I figured I would jump in with that in case you hadn't considered it. Since your tank isn't set up, it's easier now to figure this out than later.

Even without the up/down elbows, you still would have the same functionality (safety) but you may have noise from both pipes and you're splitting the flow. If the skimmer is on one side and scrubber on the other, pump in the middle, then I see why you would run them split 50/50.

Thanks for the advice. When I get home today, I will see if I can fit the elbows in the overflow box. If I can fit them, then I will try the Herbie method. the sump hasnt been assembled yet so I will also look into making a chamber large enough to fit the ATS and skimmer.

Thanks again

Erik

PS: I will also rough the screen up some more.

 

[TheFishMan65]

The elbows are not needed for a Herbie.
Drain one is a full flow (siphon) with a valve turned down until all air is out of the line.
Drain two is an emergency. The inlet needs to be higher than the normal water level of the over flow, but low enough to create a siphon and take the full flow if needed.

 

[Floyd R Turbo]

First - when you use it, make sure the top of the sensor is exactly where the surface of your screen is.

Check. Test will be done with the screen and inner box removed - lights only. I don't think I will be able to test with the inner box in place, but I can stick another sheet of 1/4" acrylic in between the light and meter to simulate it.

Second - Just to state the obvious, brightness levels will vary around your screen. One reading in the center of where the light shines will not tell the tale.

Check. Have seen pics of several tanks with PAR readings inserted all over. That's what I was planning.

Third - For anyone using a PAR meter on light that is skewed blue (like true 20K's or Royal Blue LEDs), PAR meters to a poor job of reporting the PAR from those frequencies - generally under reporting them.

I knew I read something like this before. Is there a thread somewhere that discusses this? This goes back to the whole light intensity versus perception issue. This is why people fry their corals when they switch to LEDs from MHs or T5HOs, because they don't "look" as intense, but actually are way more.

My original plan was to "dump" the water on the screen. But that did not work. So the one I've been using and showing is indeed inserted into the PVC slot. But one edge is siliconed to the PVC so water only escapes on one side.

Ahhh. I'm pretty sure this could become (or coudl currently be) and problem. Follow me here. If algae attaches to the screen, then grows outward from the screen forming a mat, the 'roots' that hold the algae on the screen will need 1) light and 2) flow in order to maintain the require strength to hold the top layers of algae onto the screen. As the algae gets thicker, the light does not penetrate as deep, but the flow still allow for nutrients to be taken up and strength maintained.

Your screen forces the water to flow on only one side of the screen, and then as the algal mat grows, the water flows more and more over the top of the algae and less and less gets to the roots. The algae grows outward and blocks light and flow, the roots lose strength and detach. I believe this is why you are seeing bald spots on your screen - not due to high nutrients (which cause black slime that blocks light).

I don't think I've seen anyone try to force a one-sided screen by way of siliconing off one side of the slot. The reason you don't want to do that is because of what i just described. For a one-sided screen (lit only from one side) you need to have the full 35 GPH/in and flow to both sides, because the flow to the back side (not lit) still has a function, providing nutrients to the roots which are already light-starved.

If you are unable to double the flow and remove the silicone, there may be a fix: slant the screen. This would allow a little more water to penetrate through to the deeper layers and to the roots. But it also may cut back on the filtering capacity a bit. Honestly I don't know which one would be better, a single-sided half-flow screen with a 10 degree slant or a single-sided full-flow vertical screen.

D*mn! That would be too cool! From our conversation I gather you think these particular 'pods are too small to see? I'm happy to donate to someone with a microscope if so. Heck, I'VE got a decent microscope myself.. but I'm FAR from qualified to discuss (much less identify!) what I'm looking at.

Baby copepods are microscopic and you will have millions of them by the end of each week! That's why (when I remember it) I dip my screen in the tank and swish it lightly before cleaning it.

 

[Floyd R Turbo]

The elbows are not needed for a Herbie.
Drain one is a full flow (siphon) with a valve turned down until all air is out of the line.
Drain two is an emergency. The inlet needs to be higher than the normal water level of the over flow, but low enough to create a siphon and take the full flow if needed.

Right, but he already has bulkhead in place, so the up-turned elbow would be needed.

 

[TheFishMan65]

mistaflicksta, I think I am picturing a different design than Turbo. If you need help PM me (or probably Turbo) or post on the Herbie Thread lets get back on topic in this thread. I will be happy to try and answer any questions(yes Turbo, I wrote a summary for those also, but they didn't take off ).

 

[scolley]

I knew I read something like this before. Is there a thread somewhere that discusses this?

I believe there is. But I'm afraid I've got no idea where it is. Sorry.

come (or coudl currently be) and problem. Follow me here. If algae attaches to the screen, then grows outward from the screen forming a mat, the 'roots' that hold the algae on the screen will need 1) light and 2) flow in order to maintain the require strength to hold the top layers of algae onto the screen. As the algae gets thicker, the light does not penetrate as deep, but the flow still allow for nutrients to be taken up and strength maintained.

That could explain things falling off my screen - or at least a major contributing factor. But I have to disagree with the idea of letting water provide nutrients to the underlying algae from the back side. Let's call it the "anchoring layer" since the word "roots" has no place in an algae discussion - as indicated by your use of quotes...

Anyway, that anchoring layer requires two things to remain alive; nutrients AND light. Makes no sense to provide water flow for nutrient if it is not getting light too. Plants (even simple ones) CANNOT use without the other... simple photosynthesis. So while I'm certain nothing will be gained by providing one half of the equation (nutrients through a wet back side), I'm convincing myself that this is not the reason why things have fallen off. I say that because in other people's setups - yours as a great example - it looks like there's great growth on both sides of the screen. If thick growth is happening on both sides of any portion of your screen - and it's not falling off - then both the light AND the nutrients are penetrating to the anchoring layer. Or it's not needed. Otherwise you would have algae falling off one side or the other. So if it penetrates on yours, it should be penetrating on mine too. So maybe the one-sided setup is not the issue after all. Or so it would seem to me.

Baby copepods are microscopic and you will have millions of them by the end of each week!/QUOTE]That sounds great, no doubt. I trust this has been confirmed somewhere?


Thanks for all the help!

 

[Floyd R Turbo]

I get what you're saying, maybe I need to re-state my thoughts (feeling rather ill today).

If the algae grows thick enough, it will block the light to the lower layers. That is true for any setup, which is why you clean weekly, because when you start to go past the 1 week point, the anchoring layer (thank you, better description) loses light exposure. However, algae with good flow needs very little light to maintain strength, given that the substrate is rough enough and the screen is mature enough, and it doesn't go too long before eventual cleaning.

This is where I feel the flaw is exposed in your system. You are restricting the flow to one side and one side only. As the algae mat grows, water takes the easiest route, which is over the top layer of algae. Some will penetrate through to the lower layer simply because of gravity, but I think it is enough of a difference that you are losing flow to the core of the screen, and it's enough to allow algae to detach.

If you allow full flow to both sides then the flow will split between the front and back, and you will lose the effect of the flow that goes to the back (which was your intention to eliminate by forcing flow to one side) but the end result is a screen core that is too dry.

Anyways, that's my theory. I'm just looking at pics of your screen where you have huge clumps on one half and nothing on the other, then there are round bald spots that correspond size wise to the clumps, and I have to imagine that you has a clump detach at some point.

The copepods might also contribute, they eat away at the anchoring layer which would allow weakening and detachment also, so I see srusso's point too. Are you cleaning weekly and running under fresh water? FW kills the pods, but leaves enough so that you'll have more in no time.

 

[TheFishMan65]

One other possibility that I admit I don't completely understand, but from reading think it could be a problem. What do you think?

If there is no/low flow in the anchoring level, then it may go anaerobic (no oxygen). Would/could it then start to produce Hydrogen Sulfide? Would this eat away at the anchors?

I understand the principles behind this, but not all the requirements. So I am throwing this out there for discussion.

Thanks

 

[Enjoy]

I took some pics of the ATS screen being cleaned. Here is the progress....

Dirty:

Harvest for 1 week:

All Clean:

 

[Floyd R Turbo]

Looks like a good start. How much flow do you have?

 

[srusso]

Looks like a good start. How much flow do you have?

Yeah, I was going to say the same. Looks like low flow and low light though...

 

[Floyd R Turbo]

Enjoy, I looked back in the thread and noticed you said the screen was oversized for your tank, but what size is your tank?

The screen is only a week old, so the screen is still ramping up, so it's hard to say if there is a light or flow issue, so I was more curious than anything else.

When you do your next couple cleanings, make sure that you just use fingertips (not nails) to gently remove the clumps/strands, and try to leave some strands on. If there are some really long ones, try to break them so that they are still an inch or so long (if you only have a few - and you're probably past that stage anyways). Within a few weeks, it should have more broad coverage and then you can try using fingernails (lightly). Use very slow running room temp water, and not a sprayer.

But always clean the top of the screen (slot entry point) with a toothbrush.

 

[Enjoy]

The screen is much too large for the system. The screen is 12" x 12" - Lit from both sides, and the total water volume in the system is around 40g.
I have the ATS "tee'd" off of my main return line, and I am aware the flow needs to be greater. I plan to upgrade the return pump very soon, but figured it would hurt to let it run as-is for now.

I am currently using (2) 23w 2700k CFL bulbs which for my total water volume is ok, but for the screen size - it's not enough.
My main reasoning for making a larger ATS was that I might possibly transfer it to a larger system in the near future.

Thanks for the advice in cleaning the screen. I went over the whole screen with an old acrylic scraper, then lightly over the entire screen with a toothbrush. It has been 3 days since I cleaned the screen and it already covered in the brown diatom looking algae. But, I'm pretty sure that is common.
I will upgrade the return pump and throw some more light at it. I will post back with updates.

Thanks again

 

[Floyd R Turbo]

I would say that if you're only running a system with 40g of water, then leave it alone. The lights are fine, matched to the tank volume, and the only real concern is the flow rate. It would be better to just feed from your sump intake vs off the return line.

I would say that you over-cleaned it, but it's not that big of a deal. You have to scrub pretty hard to get all the slime coat off from that first week, you can see after cleaning that it was still brownish, so you're OK. Just take it easy on the next couple cleanings.

You're right about the diatom algae. Diatoms will always grow on the screen, simply because they are the fastest growing. When I clean my screens, I rinse that all away and keep the green hair and dry it out and use as plant fertilizer.

 

[srusso]

The screen is much too large for the system. The screen is 12" x 12" - Lit from both sides, and the total water volume in the system is around 40g.
I have the ATS "tee'd" off of my main return line, and I am aware the flow needs to be greater. I plan to upgrade the return pump very soon, but figured it would hurt to let it run as-is for now.

I am currently using (2) 23w 2700k CFL bulbs which for my total water volume is ok, but for the screen size - it's not enough.
My main reasoning for making a larger ATS was that I might possibly transfer it to a larger system in the near future.

Thanks for the advice in cleaning the screen. I went over the whole screen with an old acrylic scraper, then lightly over the entire screen with a toothbrush. It has been 3 days since I cleaned the screen and it already covered in the brown diatom looking algae. But, I'm pretty sure that is common.
I will upgrade the return pump and throw some more light at it. I will post back with updates.

Thanks again

You are right, it cant hurt. I agree with Floyd, rather then buying a new pump use your overflow.

 

[pskelton]

Question,
I just cleaned my screen for the 6th time. I have been scraping the algae with a kitchen stoneware scraper. (Looks a lot like Floyd's Scraper). My nitrate has been in the solid 50 60 range for the last 3 cleanings. In the first three weeks of operation nitrate dropped from 150 down to where it is now. The algae is very dark with very little hair algae mixed in. I had been seeing an increase in algae cleaning to cleaning but my last cleaning (Palm sized hand full) Is the same amount as the previous week.

Using the above described tool do you think I am scraping to much? Should I just brush the algae with my fingernails so as not to remove most of it or should I just keep scraping the screen with my tool. You can see a picture of the scraper I am using in the link below.

https://www.pamperedchef.com/ordering/prod_details.tpc?prodId=241&catId=9&parentCatId=9&outletSubCat

 

[Floyd R Turbo]

That's funny. I wondered where my wife got those! Thanks for the link!

What is your P reading at? If it's zero, then you're P limited and N uptake will slow, and you may have to add P to the system to get the N down.

Would you say that your algae is black and more like a slime coating the screen, or is it just very dark green or dark brown and stringy?