Hello! Wow, am I excited to be here and actually running an ATS! I have a 20 gal tank with a 10 gal sump currently. I'm running it as an experiment with an ATS and as a proving ground for how I will set up my larger tank later this summer. I have two juvenile Northern Diamondback Terrapins that are rapidly growing and will need a bigger tank soon. Since Terrapins are brackish turtles, I keep the water between 1.016 and 1.020 specific gravity. I allow this to fluctuate with the evaporation in the sump to better mimic the estuarine environment they come from. The turtles also have some fish for company as well as some inverts for clean up. The new tank this summer will be a 160 gal 3' x 4' tank with 20" water depth with a large sump, and I want to get this all right before I make the investment in the tank in time and materials. So... I'm into week 3 with the scrubber. After about a week I had a quick bit of brown algae then almost immediately started growing nice emerald green hair algae. I made my first screen scrape of the mesh and rinse in the sink on week 2. During the 1st week I still ran my regular in-tank filter (just simple mesh with some activated carbon). Then I turned that off and pulled the carbon out as the green algae started growing. Since then the water has been getting more and more cloudy each day. I know the ATS should produce DOC. I just seem to have an awful lot. My water has gone from pretty clear to very yellow. My sump has now has some algae now clinging to the walls, though there seems to be none in the display tank. Will this greenish yellow water clear up as the hair algae starts growing faster? Is the system just a little too new? Should I start running the activated carbon again? If I understand correctly, the carbon will pull out a lot of DOC. If I also understand correctly, those DOC are beneficial to the tank and to the algae. Thanks in advance for your thoughts and advice!
I always recommend making no changes to your system until the scrubber has "proven" itself. That way, you can pinpoint any issue with the scrubber. I would add the filter mesh and carbon back in. The other aspect that might be affecting things is the brackish water. Freshwater scrubbers tend to go green a lot faster, and the type of growth is different. Typically, it is finer hair algae, almost human hair like, and somewhat fragile. For the first few months, it can tend to break off very easily, the screen takes a long time to build up a calcification layer (whereas in SW, this happens a lot faster) and that layer is what solidifies the anchoring of the algae growth to the screen. Brackish water is likely a bit of a crossover between the two, but admittedly I don't have much knowledge of the behavior of brackish water algae scrubbers. So I'm making some educated guesses here. The water coloration might be related to the water type also. I've heard feedback that FW scrubbers do tend to discolor the water. If you put a filter sock on the output of the scrubber, my guess is that it will turn green very quickly. This may lessen over time. So in short, I would add the filter mesh and carbon back in, and don't otherwise change your maintenance routine because of the scrubber until it gets s foothold and is functioning well. Also, post your scrubber specs and some pics: size, lighting, photoperiod, flow, etc. Welcome to the site!
I have a 10 gallon brackish (18 ppt) running with a DIY upflow scrubber and also been getting yellow water. This is a tank for feeders; the only other filtration is a sponge filter. Scrubber has been running for about 5 months and the water seems to get yellow pretty quick after a water change. Usually one large (75%) change every few weeks. Prior to the scrubber the water stayed fairly clear. I’ve noticed a drastic reduction in the number of dead shrimp while running the scrubber with similar stocking, feeding, and maintenance. So, I’ve assumed this was a net improvement in water quality despite the decreased clarity. I have been messing with the scrubber lights a good bit trying to improve the growth. I have replaced the screen once thinking it wasn’t rough enough allowing detachment. Recently I’ve been getting more consistent green growth but still not the typical salt water GHA.
Thanks Turbo! Good to be here, and thanks for the advice. I guessed you might say that, so I turned the little filter back on the other day. Things have improved quickly. I am on the highest end of brackish, so I think I tend more towards a marine environment, but the jury is out. There just aren't enough in the hobby that fool with this in-between water nonsense, lol. I quite like the challenges it provides tho. Finding plants that are happy is the hardest part. Once the new big tank is ready, I will be going with some seagrasses that are brackish-friendly. So, the tank is: 20 gal (with about 12 gal in the display) 10 gal sump 1.016 to 1.020 S.G. 125 Watt metal halide for basking w 12 hr photoperiod 2x 13w 2700k for waterfall ATS w 18 hr photoperiod (opposite display) Aqua Medic DC Runner 1.2 Pump split between display return and ATS. It's 317 GPH, so I'm thinking I have about 75 or so to each. I have it dialed in just by sight so the screen flow looks right. Tetra Whisper 20i Internal Power Filter (GAC and filter floss) 100 Watt heater Beananimal overflow DIY stand Taylor the Terrapin: Overflow and Pump Controller: Not much room inside here: Left and right of screen: Pipe to block light, control splashing, and even-out the flow over the top of screen: End of 1st week with scrubber:
Just finishing up the plans and design work on the new tank, and I thought I'd post a few pics. Still need to finish the plumbing, sump, ATS, and cabinetry tho. Almost done and almost ready to start the build! Stoked!
Nice concept! From a structural standpoint, the drop-off design add a level of complexity that you might not need, and makes it harder to make the stand that matches it. You might consider just making it full-depth all the way across. This would mean much more sand, but a much simpler setup. How big is that tank? Looks like maybe 60g volume of water and about 100g total size? Acrylic or glass?
Thanks Turbo! The tank has a 48" front panel, 36" wide, 20" deep with water, and overall 30" deep. Maybe about 19.25" deep with the overflow weir teeth being an inch deep from the top. It's 140 gallons wet and would be 225 if the beach wasn't there and filled to the top. The sand is 10" deep and there is 10" from the sand to the top of the tank. With two turtles (that will as adults have up to 18" combined length) I will need about 180 gal if you figure 10 gal per inch. Between the 40 gal sump and the display I should be good. I have to have the sand section back there to allow for egg laying, which will start in about 5 years. I'm doing it out of acrylic with euro bracing around the front and two sides. I like that the acrylic joints form a stronger bond than glass and silicone, and I like that the acrylic is much lighter. Thankfully all of my cuts will just barely fit into two full 4' x 8' sheets of 1/2" acrylic! Acrylite GP is $275 a sheet at my supplier plus another $20 each sheet to do all of my cuts. Not too shabby... I hadn't considered much structurally for that section, other than some wood supports. I may make the plywood top 4' x 4' instead of the way it's pictured and just add some 10" supports beneath. My thought for having it empty grew out of wanting easy access to the plumbing there and for the beach bottom piece to provide support for the inside back wet panel to prevent bowing. That's why there is no euro brace on the back top of the tank. More thinking to do I think... One big question for you... How to size my scrubber? I will absolutely be using LED's for lighting. Since my bioload will be increasing over the next few years as the turtles grow, how should I set up the screen? Should I just cut a new slot pipe every year or so to match the demand? Should I build it to the correct final size now (based guesstimated future bioload) and just run a shorter photoperiod the first few years? Any thoughts on that would be greatly appreciated!
When it comes to tank building, what you have to consider is the order of assembly. Normally, you bond the sides to the front, then both to the back, then the euro, then the bottom With a dropoff tank (which your design is a hybird dropoff) you can't do that. You have to bond things in a quite different order in order to get the bonds to work as you need each set in a specific way. In this case, if it were me, I would bond the back panel to the upper dropoff section (the floating bottom), then bond that assembly to the wet back panel (using a supporting jig, as the far back panel will be horizontal for that step), then bond that 3 piece assembly to the bottom panel, then bond the front panel to the bottom panel. After that is done, bond one side, then the other. As you can probably now see, this is quite different and injects some complicating factors - the need to build jigs at various stages to hold the parts in the perfect position while joints cure. This is all using the pins method also, which is critical, and also means that your jigs need to hold things in the 'final' position, not the 'pinned' position, as you want the joints to cure without air bubbles intruding, which will be pretty tricky. So I hope you have some tank building experience, or at least know someone who does. As for the euro, it's always advisable to have a one-piece euro that goes all the way around. Piecing one together might work for yours as you aren't filling the tank all the way, and thus the stresses are significantly less, but it never hurts. usually you want a crossbrace every 24" but again, you aren't filling the tank so this might now be necessary...but I can't say for sure without consulting with someone. It just comes down to stress on the corners, and avoiding sharp 90s at all costs - which focus stress. Back to your question though, you can over-build a scrubber, and then just use less intense light. You can also slow down the flow in concert with less light and you will just grow less algae, the idea being to balance flow, light, and nutrients. Then, you can increase flow/light when your bioload increases over time. Making a larger slot pipe is not a big deal, and adding a second section of screen next to an existing one is perfectly fine to do as well. So you could go either way, not sure there is really an advantage to either one in the big picture
Good point on the construction order and jigs. I hadn't considered that at all that it would go together any differently than the standard 5 pieces, and it's obvious that you put a lot of thought into that for me. Thank you. I do like the order you suggest. I was planning on using Weld On #4 and the capillary method instead though of pinning everything and using #40. I can't imagine needing a bond stronger than 2,000 psi. Do you usually use #16 or #40 and the pin method for your scrubbers? So, for the ATS I'll go with a bigger screen with less flow and less light for now. I'll include a valve and will up both light and flow over time.
You don't pin with 40 that's 2 part and that's completely unnecessary until you get to 2" thick material or butt-joints, bullnose tanks, cylinders, etc. You use pins and #4 or #3. Never #16, it's junk - only good for patching and various other applications but not for primary joints on a pressure vessel. Ignore "bond strength", for many reasons, it really doesn't matter. If you really want to learn the details, go here: http://www.reefcentral.com/forums/showthread.php?t=1056956 and read for about a month. Or just search for all of my posts over the last 6-12 months, you'll find a couple in there that detail the general process. Needs a summary...
Thanks for the link to that great post. Thanks also for putting up with some remedial discussions with me. I've read through more than a few huge long topics like that, but there are obviously more I need to read... Getting there. Anyway, can't wait to get this together and can't wait to post some pics of the tank, a thick green ATS and happy turtles.
