Finally back with a new scrubber

[Marksfish]

So, after 6 years and promising myself to get a scrubber again, I have finally done something about it. A few weeks ago, I salvaged a screen from an abandoned project, set it up in a very basic way under the skimmer outlet, then added a large 45w cfl over the top. It has been in there now for over a month, looks a bit Heath Robinson and it is:

https://i.imgur.com/9o8qIIjm.jpg?1

It does grow some minor algae, here we have 20g harvested off the one side:

https://i.imgur.com/UeAQmjOl.jpg?1

Anyhow, one side of the screen is seeded, now the new unit has arrived it is time to put it into action. I have seen one other review of this unit from a couple of years ago, the seller has added extra lights each side now. For about £120 GBP, I don't think it is too bad and much better than I could make.

https://i.imgur.com/XqL6Ax5l.jpg

https://i.imgur.com/UMxONbfl.jpg

When I get the chance to get in my system (hand bandaged after surgery), I will take some readings and see what occurs. I am under no illusions that the lighting may not be sufficient, but this seems to be quite well built, no light spill, but the seller seems to thing a flow of 400lph will be sufficient. Not convinced, I have 3000lph running over my last unit!

Mark

[SantaMonica]

Welcome back. The overflow version will work, if enough light. And the waterfall probably does need more wattage as you said, but might as well use what you have now. Besides, can't get too much more wattage into that closed compartment because it will overheat.

At least it's not 240/120 line voltage.

[Marksfish]

I trialled 3x 3w 660nm leds on my old scrubber and the growth was pretty good. I'll see what happens with these, then maybe source a heatsink and add them at a later date. Hoping to have it running by the end of the weekend.

[Marksfish]

So, I managed to get the unit into my sump yesterday. It wasn't quite long enough to sit on the brace bars, so had to make a basic support for it. Headroom for easy maintenance could be an issue, but I expect it to improve once nutrients lower and I can remove the skimmer. It is also difficult to remove the light covers as they fit in a groove and slide in from the top, so difficult to assess the flow across the screen.

https://i.imgur.com/JNeW9Rfl.jpg

https://i.imgur.com/U1aQL4Sl.jpg

There is only one drain on this unit, no emergency overflow, but the hole is quite large and fitted with a tank connector. Once running, as I thought, it was quite noisy draining out of the unit with the water splashing. A quick trip to the LFS and a purchase of some 38mm flexi tube and it now drains under the surface, now silent running :)

https://i.imgur.com/qsFizzdl.jpg

My thoughts of using the original screen went out of the window as it is about 2" short of the slot. I have had to fit it as a temporary measure as the supplied new screen hadn't been roughed up. I am hoping that the green which grows this week on the old screen, I can harvest and rub into the new screen to help seed that a bit quicker. Nutrient levels have been allowed to get out of hand, so am looking forward to seeing how this goes. Once new screen is fitted and running, I shall take some parameters and post, then follow the experience.

Mark

[SantaMonica]

You mean the screen length left 2" of open slot?

[Marksfish]

Yes. I stuck a little bit of tape over the slot as a temporary measure. I need to get my hole saw and rough up the new screen, but can't get my hands wet changing for another week as I have had hand surgery and can't get the dressings wet (plus it will sting like Billy O :) )

[Marksfish]

So, it has been going for 7 days and the screen is filling with an oily algae on both sides which is good, shows some of the excessive nutrients are being reduced. I am also dosing vodka at 5ml per day whilst bringing the levels down. I am still vodka dosing alongside in an attempt to get levels lower, before removing the skimmer. When first tested No3 was a shocking 50ppm, today it has come down to 25ppm, still excessive, but better. Po4 is showing as 0.5, both tests are Salifert. 10g of algae came off the screens today, so I have used it to seed the new screen.

Side 1

https://i.imgur.com/uXuQliDl.jpg

Side 2

https://i.imgur.com/p7VcSJMl.jpg

New screen, seeded with older algae and filling the complete slot.

https://i.imgur.com/sDx9vYYl.jpg

[Marksfish]

A little disappointed with today's maintenance. Although not quite a full week, it can be seen that the water is not flowing fully down the screen. I have taken the opportunity of upgrading the pump to the Maxijet 1200 in the hope that it floods a bit better. A grand total of 0g off the screens today, although a tiny amount was removed. Still 5ml of vodka per day, still skimming, No3 25ppm, No4 0.5.

https://i.imgur.com/Wp8fklrl.jpg

https://i.imgur.com/gqaIEXTl.jpg

[SantaMonica]

Yes that is very, very little flow.

[Marksfish]

Found the box for the pump, 800lph. So the Maxijet won't give much more. It worked okay on my original home made scrubber all those years ago, so no reason why it shouldn't now.

[SantaMonica]

About 200gph, good for up to 6" of slot.

[Marksfish]

The spraybar seemed to be blocked and spraying inside the unit, so it was removed for cleaning. You can see a build up around the slot and I am not sure that the slot is wide enough. It only seems wide enough to put the canvas in, with not much room for anything else, making clogging easier.

https://i.imgur.com/ucsPUUv.jpg

https://i.imgur.com/2AQbyfN.jpg

Produced a bit more growth this week with the new powerhead, 6g of oily today so it seems the screen is acting okay and hopefully will create more of it in the coming weeks.

[SantaMonica]

If the screen can fit, there is probably enough room, because water goes through the holes. But 3mm width is good.

[Marksfish]

Much more of the same this week, although 9g removed from the screen this week, a 50% increase in last week. Still not convinced I have the flow right yet.

https://i.imgur.com/VEY7S5Kl.jpg

https://i.imgur.com/UyUZBFPl.jpg

https://i.imgur.com/vd8YVCzl.jpg

[SantaMonica]

Flow is fine if growth is across the screen. Lighting is weak, causing dark slime which is letting go.

[Marksfish]

Always knew the lighting could be a bit too little for it, thinking of other solutions. I seem to remember though that on my old CFL scrubber, I had to put 2x 45w to give the growth a boost, then I could go back to the lower wattage bulbs.

[Marksfish]

No real progress with mine at the moment, still only getting 10- 12g per week, which is terrible. I have increased the photo period by 2 hours while I am still looking for replacement lights.

[Marksfish]

Ok, so I have finally found the time to add the new lights. These are 10w, 660nm 12 volt lights, for safety. A drip loop is in place and the power supply is located well away from any water and outside the cabinet. The power supply is also plugged into a 30ma RCD, standard for domestic use in the UK. It is not an ideal situation, but hopefully it will work for a while whilst I continue my research.

The rubbish led strips provided with the unit were almost falling off and not very efficient. Even with the increase in lighting time, only 19g was being produced on a fortnightly basis.

https://i.imgur.com/bMP2Z2Kl.jpg

https://i.imgur.com/7Dg6f7hl.jpg


Because the slot was so small, it blocked easily causing water to squirt around the enclosed spray bar area. As you can see, almost as much algae growth on the window as there is on the screen!

https://i.imgur.com/daUlNZCl.jpg


I bought myself some waterproof connectors and connected my new lights up and tested them. Mounting the lights on the scrubber was not an option as the light would be too low. Some bargain window board was cut to the width of the scrubber, fitted in the slots and lights attached Just for safety's sake, I taped the board on the outside as well, "just in case". A tip I saw on another forum was to cut some filter tubing an cover the 12v connector fittings and (hopefully), prevent corrosion, although these are also outside of the cabinet now.

https://i.imgur.com/xtyfYb2l.jpg

https://i.imgur.com/Y8b8ASTl.jpg

https://i.imgur.com/LGGBiXHl.jpg

https://i.imgur.com/ouPCCJ7l.jpg

https://i.imgur.com/RCnbHnfl.jpg


And there it is, running with the new lights. Hopefully it will be better than what was there previously and I will now get some good growth. I am thinking I may need 2 more, so there are 2 on each side and giving full screen cover.

https://i.imgur.com/u43T08Ql.jpg

https://i.imgur.com/2qCRcx2l.jpg

[SantaMonica]

Yea most growth is going to be in front of the light, so for that wide screen you will need at least 2 more lights (total of 4) and maybe 4 more (total of 6).

[Marksfish]

I think it will be a struggle to get 3 units per side, but 2 is doable. Just need to sort my flow out, seems to be okay at both ends, but miniscule in the middle. Sods law eh ;)

[SantaMonica]

Also if you can back the lights up, they will spread out more.

[Marksfish]

Yes I agree, they are very close and a 10w led may possibly burn the screen at that distance. I need to try and fathom out how to mount the lights, I may have to make a "beam" which runs across the top of the unit and allows the lights to hang down. It seems to be the only way to increase the distance :(

[Marksfish]

As expected, the led has proven to be far too strong and I have a big white circle on the screen. Until I can make adjustments, I am trying to diffuse the light a bit. I first started out with a bit of new canvas:

https://i.imgur.com/1vLBdYul.jpg

I didn't think this would diffuse it too much, so I had a bit of a look around. I then squeezed a take away container lid in between :)

https://i.imgur.com/2lmVjusl.jpg

Hopefully that should help the situation a bit until I can try another way of mounting the lights.

[Marksfish]

Some more modifications made today. I have found a way to hang the lights away from the screen. As you can see from the following pictures, the led really did burn the algae!! That said, 18g harvested today in a week, wasn't getting that before with the old lighting set up, so onwards and upwards to increased growth.

https://i.imgur.com/1x2cknFl.jpg

Side 1

https://i.imgur.com/1A33VlSl.jpg

Side 2

Both lights are now about 10cm from the screen allowing for the spread of the light, hopefully it will spread enough, although there is still a "spotlight" effect. On a previous home made version, 3w leds were enough to produce great growth without burning, so 3 times the power could prove to be a bit troublesome.

https://i.imgur.com/RQHY7CHl.jpg

https://i.imgur.com/5MzHbiTl.jpg

[SantaMonica]

You could try putting some triangle acrylic strips on the light, to diffract the light sideways.

[Marksfish]

So here we go, now some results are starting to be achieved. With the light timings lowered from 18 hours per day to 13, in a week the screens have produced 30g, that's a just over 50% increase on last week. The big white burn is filling in nicely, so hopefully that will produce some good growth now, although looking for something to diffuse the main beam is still ongoing. Once the screens are filling with a decent amount, I shall increase the lighting again gradually until up to 18 hours. Still got a way to go to top my 200+g per week, but now moving in the right direction! Some wet oily growth pictures :)

https://i.imgur.com/FshJIaJl.jpg

https://i.imgur.com/TqShVlml.jpg

[SantaMonica]

Yes once a growth ring has filled in, you go use more hours of light.

[Marksfish]

So I am now 6 months into my journey, I have decided my lights aren't strong enough to encourage initial growth. I have increased lighting time to 22 hours now and am still only getting 22- 25g in total per week off both sides. It is still a slimy algae, nothing like my previous experiences. I still have some 45w cfl that I used to "kick start" my old scrubber when 4x 10w cfl wasn't sufficient. I believe the 10w leds will be sufficient to maintain the growth once it has begun. Need to hunt out the bulb holders now :)

[SantaMonica]

Yea if that led can't even create a white growth ring right in front of it, it's too weak.

[Marksfish]

I had moved the leds back, as you can see from the pics above, there was a very definite ring when they were closer. Until I find the holders, I may move them back a bit closer again.

[Marksfish]

Found them. 2x 45w cfl in position temporarily with temporary reflectors. Hopefully this will now give the screen the kickstart it needs.

https://i.imgur.com/uhdQKj7l.jpg

[SantaMonica]

Ah the good ol days of big cfl's

[Marksfish]

So a week after adding the cfls and the difference is like night and day (excuse the pun) :)

https://i.imgur.com/Isurrkql.jpg

https://i.imgur.com/FAK94WMl.jpg

https://i.imgur.com/POrT6GAl.jpg

I appear to have a little bit of a flow problem, so all cleaned out today with a toothbrush. Hopefully it will stay flowing well for the next 7 days. Double the amount of product produced this week, so here's to the next few weeks' harvests.

Mark

[SantaMonica]

Much better. What you are getting now is the thin growth layers of over-sized screens. They work fine but usually don't have enough nutrients to grow thick across the whole screen.

If you want you can cut the screen vertically to make it about 30% smaller, then tape up the remainder of the slot. This will give more flow and concentrated growth in front of the light.

[Marksfish]

It's a 4' system still with quite high no3 and po4 readings (need some new tests to give a good reading), presumably leaching out from the 5 year old or so rock. This size screen is roughly what i was using last time on a 3' system and gaining 200g per week growth. Could it really be that a smaller screen is needed for a bigger system with more livestock? I was thinking it is because the bulb is quite close to the screen and the water flow still hasn't been tweaked enough yet. Also, the bulb positioning favours the right hand side of the screen (top pic) as the bulb isn't as long as the screen, so less light is being reflected onto the screen. I also seem to remember having to use some iron fertiliser as well.

[SantaMonica]

Ok then it's probably just too slimy to growth thick.

[Marksfish]

So, new Salifert test kits. No3 25 and Po4 1.

When I started with this back in December, No3 was 25 and Po4 was 0.5, so I am going backwards at the moment with the phosphate. I was also vodka dosing and using a skimmer when I started, I stopped the vodka, so maybe I need to restart that again to help drop the nutrients down again, then hopefully the gunk will go and proper growth begin. I'm sure I used to have a higher flow rate on my original, but don't have that info any more, i'm sure back at the time more flow was better, it seems to have changed now.

The dosing will have to wait as I am away with work next week, also the screen will be about 12 days old by the time I get back. Let's see what happens now! I have also added some iron fertiliser to try and help the green, just hope it doesn't get skimmed out!

[SantaMonica]

1.0 phosphate will certainly get you dark slime. This still filters well, see below. If you get it harvesting enough, you should not need to dose. Iron is not the problem with dark slime; that's only the problem with yellow growth. Doesn't hurt though.

---


Sometimes people see lots of pictures of green-hair-algae packed scrubbers, and then worry when their own scrubber is only growing slime. Well, here is some good news: slime pulls out more nutrients from the water than GHA does! And this goes for dark, and especially black, colors of slime.

Now this may sound the opposite of what you have heard. But think about it: Scrubbers usually start off growing slime first. Why? Because nutrients in the water are usually higher when a scrubber is first installed on a "problem" tank. So, slime can handle larger amounts of nutrients at one time. This slime starts off first, coating the surfaces, and quickly pulling nutrients out of the water. If nutrients in the water are higher, the slime is darker, which is even more dense with nutrients. As nutrients in the water come down, the slime then grows less dark. Interestingly, the slime coating also prevents GHA from attaching. Slime is king! So why then does everyone get lots of GHA, if slime works so well?

Because slime can't hold on. Slime is all about holding nutrients; not about holding onto surfaces. Holding onto surfaces requires growing cellulose structures that can hold on better. Cellulose structures like the roots and branches of trees don't do any filtering but hold on great; the leaves do all the filtering of the air. But leaves can't hold on to the ground, so the roots do that instead. In algae, the softer structures like slime do the filtering, but can't hold on. So GHA evolved a more solid structure to be able to hang on. Bryopsis takes this even further with "roots" that dig into rocks to get nutrients from inside them. Even GHA has the ability to use enzymes to dissolve into silica rock as a way to anchor itself. But slime just has trouble holding on.

Slime holds on best to rocky flat surfaces, like our Green Grabber rocky textures. Slime does not hold on that well to plastic screens like those used in waterfalls. So rocky texture scrubbers will pull nutrients out faster, and stay covered in slime longer, thus providing better filtering in high nutrient water.

But all slime washes away if not harvested soon enough, such as every 3 to 5 days. So to get the benefits of slime, especially black slime, harvest as soon as the surfaces are covered. This usually involves brushing under running tap water. This will pull nutrients out of the water so that GHA can subsequently attach and grow.

[Marksfish]

Wow, that was a comprehensive answer and has given me info that I didn't know before. I knew slime came fast, but didn't realise the slime filtered better, I always though the goal was the turf.

[SantaMonica]

GHA is easier to deal with, and more fun to look at, and you can feed it to fish, so it's generally preferred. But yes if you deal with the slime more frequently you can get good filtering from it.

[Marksfish]

Not so impressed with the cfl's ability to bring on growth this time, although improvements seem to be being made. When I tried it out last time, I had some cracking growth. I think I am going to have to change my pump out for one with a larger bore. I currently have a Maxijet 1200 that only has a 12mm bore, which then opens up to a larger spraybar. This is obviously leading to a lack of pressure once the bore widens, thus potentially not equal coverage. I am also thinking the growth is better not in the direct line of the cfl. I have gone back to vodka dosing to try and get the phosphates down. This is a 2 week screen, only providing 5g per week more than a weekly clean.

https://i.imgur.com/tbmHDA9l.jpg?1

https://i.imgur.com/6PMacm2l.jpg?1

https://i.imgur.com/ieEaO1El.jpg?1

[SantaMonica]

I just needs stronger light right now, as heavy nutrients are coming out of the water.

[Marksfish]

It's a 45w cfl both sides. No room for anything bigger, and nothing to disperse the excessive heat that is being released into the sump cabinet already. Hopefully the 45's, although a bit longer, will still do the job.

[SantaMonica]

Well you could cut the screen vertically in half, and tape of the rest of the slot. This will concentrate the growth in front of the light, and increase flow too.

[Marksfish]

I'm going to wait on the bigger pump first. It arrived today but bl**dy ebay sellers send crap from China without the correct plugs and adaptors, thinking that is ok. Needs to be sent back and i'll get one from a proper UK shop.

Not really sure I want to go down the road of cutting the screen cut in half. This screen is about the same width as my old one (10"x 6") for a 300L (ish) system which was fine for the sizing guidelines back then, unless they have changed substantially?

I have dark green growth this week, not black, so hopefully things are starting to happen now.

[SantaMonica]

It's just a way of getting the light intensity higher across the screen, without getting a bigger reflector for the lamp. But it might just fill in by itself as nutrients come down.

[Marksfish]

Ah, I see.

[Marksfish]

Just out of curiosity, if I were to go down the route of a smaller screen, how much smaller would you say? Also when you say tape up the slot, what with? Would normal tape not leak toxins into the system?

[SantaMonica]

Narrow enough to catch all the light. And any way to wrap up or seal the open slot is fine; does not have to be adhesive tape.

[Marksfish]

I wonder if I put blu tak in the slot as a temporary measure, if that will do the same? Obviously the growth on that part of the screen will die off, but once I have drained the system of nutrients I can then re-open the slot and allow the full screen to fill in, without using a new screen.

[SantaMonica]

It if stops the water, then it will work. But water will still spread out a bit. Give it a try.

[Marksfish]

Been working hard to lower organics in the water as the scrubber obviously isn't powerful enough on its own at the moment. I have been using vodka dosing and Phosguard. The green slime has gone this week and is replaced with this clear slime.

https://i.imgur.com/amROEKTl.jpg

https://i.imgur.com/cVD5dpml.jpg

https://i.imgur.com/9Sa8fsVl.jpg

Looks like something my dog brought up :) Not sure why it has now gone clear. I have reduced PO4 from 1+ to 0.5, still a little way to go, but hopefully (after almost a year) things are now looking up.

[SantaMonica]

I think you mean reduce inorganics. Not organics. You want as much organics in the water as possible to feed the corals.

Why is one side dark? Looks like there is only light on the front side now.

You'll need to brush off all growth now that you are dosing, because the previous growth was dealing with more nutrients and now you have less. I still think you need half the screen size, because I've seen large screens like this stay at this stage. If you scrape it clean often then it will work, but it looks like you are letting it accumulate for a while which does not work well for slime.

[Marksfish]

It is still lit both sides, so have no idea why it is like it is. Both sides were clear, just some other stuff on one side. I'm cleaning every week. I know you want the screen smaller, but I don't understand why a screen this size on a smaller tank worked so well. I've been dosing for several months, so even dosing and a scrubber weren't doing the business. It has gone clear since the addition of the Phosguard, even though I have been supplementing iron as well. The only difference is that I still haven't changed out the feed pump which is only 1200lph whereas my other one was 3000lph.

I have found some pictures (below) of my old unit, where you can see a similar width, but longer screen on a smaller system.

https://i.imgur.com/Pvd4jV7l.jpg

https://i.imgur.com/JumLR7xl.jpg

https://i.imgur.com/dCI2S8bl.jpg

[SantaMonica]

Carbon dosing usually does cause growth to go light, or clear. I have just seen many screens growth more and thicker when they were not so big.

[Marksfish]

Finally got myself a new pump. All plumbed in and gushing away now. Let's see if that makes a difference.

[Marksfish]

So, this is the second harvest now that the bigger pump is on. I have had to make a slot cover out of tin foil which I have bent to shape as the slot seems to keep blocking and squirting out onto the clear acrylic. With the cover, the water is directed back onto the screen again. Possibly thinking as well that the bulbs may be shot as they are quite old and may need replacing. Still vodka dosing and using Phosguard to try and get conditions favourable for no slime. I may have to consider cutting the screen down, as much as I don't want to. Will see once it reaches the 1 year anniversary soon.

https://i.imgur.com/hGw61bql.jpg

https://i.imgur.com/jNf5RoDl.jpg

https://i.imgur.com/IOmL3odl.jpg

[SantaMonica]

Well it's certainly still low on light compared to high nutrients, so anything you can do to increase/concentrate the light, or lower the nutrients, will help.

[Marksfish]

12 months down the road and it is time for a new approach. I am holding out swapping the spraybar to smaller for the time being. I have ordered some 12v 20w 2800k leds now. I would have liked to have gone down the red led route again, but the price is just crazy. 2x warm white lights are 1/4 the price of 1 660nm 20w light!!

Although I am still only getting slime, levels seem to be holding steady, but I really need to get phosphates down. Even carbon dosing and Phosguard won't keep it down. I am hoping 2020 is the turn around year.

[Marksfish]

New light day today, other light will be fitted net week. It is now a 12v, 20w warm white. I am thinking maybe the big cfl's were losing light output, so not a lot of cop really. This is my last attempt before re- sizing the screen. I shall see how it gets on over the next couple of months before making a decision as I will have to make a new spraybar.

https://i.imgur.com/TNaxsXCl.jpg

https://i.imgur.com/hYa4kwTl.jpg

https://i.imgur.com/TNaxsXCl.jpg

The 10w 660nm red is still on the other side, hence the pink tinge.

https://i.imgur.com/3u7wASwl.jpg

Flow over the screen:


https://i.imgur.com/7pvFawp.mp4

[Marksfish]

With my set up, I have seen mention online of seeding a screen with Ulva intestinalis. Any thought on this over waiting for the turf?

[SantaMonica]

CFL will lose output after about 3 months, correct. And you can seed if you want to, but it might just disolve. It's really not needed.

[Marksfish]

Okay, I have finally decided to make the screen smaller to see if that makes a difference, as everything else I have tried to promote growth has failed. My ATS is now 16 months old and still only slime :( . My current screen is 10" x 6", so I am thinking half the width and length, or maybe a bit bigger at 6"x 4". Would that be too much or about right?

[SantaMonica]

Just cut it in half vertically and tape up the unused slot. This will fit a single light well, and will have good flow.

[Marksfish]

That's tomorrows job then, ta. I found my Milliput today, so now have something to block the slot up with.

[SantaMonica]

Or just plastic wrap

[Marksfish]

Well that didn't go as planned :(

I cut the screen in half today and gave it a quick clean. I tried to fill the slot with Milliput, but it was old stuff and was a bit too crumbly. I had now cut the screen so was committed to the change and found out a roll of sellotape. I bound the slot several times, not sure how long it will last as it isn't known for being waterproof! I then had to swap out the 3000lph pump that was feeding it and go back to the Maxijet 1200. A few more tweaks to make as I had to slot a smaller bore pipe into the bigger bore and cable tie it so it doesn't leak. The supply pipework is also a bit long and needs cutting down so I can position the screen, the feed pipe is currently pushing the spray bar off centre. It is running, but I think I will have to find something a bit more permanent in the future, once the DIY shops open up again.

https://i.imgur.com/WRWVsJIl.jpg

https://i.imgur.com/yIGKwUBl.jpg

https://i.imgur.com/bhLNfdHl.jpg

https://i.imgur.com/J7W3UaEl.jpg

[SantaMonica]

Should do the job for now.

[Marksfish]

First week with the reduced screen = Reduced amount of slime algae produced :( When the screen was bigger, I removed around 40g per week. This week, only 19g. Still nowhere near the 100s of grammes I used to get on my old scrubber with cfl.

[SantaMonica]

That's because gha has not attached yet. Get all the slime off every few days.