So I'm building an algae scrubber to test to see if it can sustain a mandarin dragonet by itself. It would be the only fish in the tank so no need for standard fish food. However ideally, I don't want to feed standard fish food if I can help it, I'd like to feed the algae with a liquid form, something that breaks down quickly into nitrates and phosphates. Does anybody know what would suit?
Usually, urea (from fish) is the best form of food for algae. Otherwise, dosing forms of nitrate and phosphate directly into the water would theoretically work, but I can't say that it's really been tried and maintained successfully long term. I remember a thread a while back on the algae scrubber site where a guy mixed up a bunch of fertilizer from a garden store and then did some really nasty things like (literally) putting a bunch of dog poop in a mesh bag and throwing that in the tank to see how the scrubber would grow. Obviously, there were no fish in the tank, it was just a test. According to SM, ammonia is a scrubber's preferred "food" so to speak. In an aquarium environment, ammonia gets sucked up pretty quick by the bacteria, so only trace amounts get "fed" to the scrubber. However, you theoretically could create a recirculating scrubber setup in which you could then dose ammonia directly into the water, in such a manner that the scrubber would uptake it for the purpose of just growing algae to generate pods. But these pods would then have to make it back to the tank, you would have to very closely monitor the ammonia levels, etc. I see potential problems. So here is a thought. If you want to maintain an dragonet-only tank, make it a relatively decent sized tank (100g) and establish it (6-12 months) with the scrubber in place, and a ton of soft corals. Corals generate waste also, and softies can live in 'dirty' water. So can many LPS. But for any dragonet to survive, you have to put them into a well established system. This is a big key point. I have a green mandarin in my 3 year old 120g, he is trained to eat NLS pellets but I only need to feed him those about once a week, and I don't know if he even finds any of them. But lots of pods live in the periphyton, the top layer of the rock that is coated with life. Without this coating, the pods population will probably not sustain enough. If you had an oversized scrubber, maybe, as long as it's growing a ton of algae, and then when you clean it, you shake it in the water first to release the microscopic baby copepods. I'd be interested to see if you would be able to do this. Maybe others will chime in and confirm or dispute my thoughts....just diarrhea of the brain in this post....late night
I'm wanting this to be a smallish tank (20g probably) with an algae scrubber and the mandarin in the same tank, therefore I can't be dosing straight ammonia etc. This is the point of the test that I'm doing - to see if it's possible for a mandarin to live with just an algae scrubber providing the copepods. SM says that algae scrubbers regardless of size release 'hundreds of thousands' of baby copepods per day. Personally I think this is an extreme exaggeration but without evidence I can't exactly argue against it (and likewise he can't argue for it without evidence of this). Mandarins only need 100+ gallon tanks because it's only at that size that enough copepods are produced to sustain one mandarin. If an algae scrubber can replace the 100+ pounds of live rock (in terms of copepod production) in an 100 gallon tank then there's no other reason that I'm aware of why a mandarin can't be in a much smaller tank, they are pretty small fish. Many people keep them in small tanks and they do fine, as long as they feed them plenty of pods. I also have a few sieves for aquariums, the smallest is down to 150 microns, which will easily catch copepods down to a small size. After it's all setup and been running for a while I think I might put the sieve below the water outlet from the algae scrubber, leave it for an hour, count the pods and work out how much it's producing per day. Exciting
I do recall that someone harvested their screen algae and kept it in saltwater, stirred it up very well, and then looked at the water closely (I don't think it was with a microscope, but not naked-eye) and there was a ton of life. So in theory, yes. But you have to have a screen that is large enough to produce enough of a breeding ground, and the algae has to have nutrients to grow. A small tank that is lightly fed might not grow enough algae to support the required pod population. So it's hard to say if that would work, but I think it would be tricky.
Yeah you are up late heh. Yeah I reckon as long as you work out the feeding schedule for it it should hopefully work. That's why I was wondering if there was some kind of liquid fertilizer that would provide enough food for the algae each day to sustain the pods. I guess once the algae scrubber is going strong, the mandarins waste is going to be feeding the algae, which in turn will be feeding the copepods, which in turn will be feeding a mandarin whose waste will be feeding the algae etc etc. A perfect ecosystem . I guess water changes would remove some of the waste so it would always require some level of feeding, but it sounds cool in principal. Edit - does anybody know if amphipods eat copepods? I've heard they do but haven't seen any solid evidence. Also, does anybody know if the copepods eat alive algae or just dead/decaying algae on the scrubber?
Wife is out of town for the weekend, so I stayed up late to finish up and ship a scrubber destined for the Philippines There is a company in Florida called Florida Aqua Farms that makes a bunch of different fertilizers, this one http://florida-aqua-farms.com/shop/micro-algae-grow/ is specifically for growing algae cultures. I have some but have never tried it. I have a feeling that it is not really safe for fish though.
Yeah not sure if i'd trust it, plus shipping to where I live would be a pain. I wonder if phytoplankton would work...it's a micro algae food that copepods feed on, and it would probably break down into nitrates and phosphates as well. Hmmmm
Pure NPK fertilisere Will help grow algae and corals its just finding the Right balance Back in the old days, with planted tanks, I think elevated K gave some more algae growth. But this was in freshwater... I am not sure it's directly the same in saltwater.. We also used lots of iron, macro, micro and trace elements
I use liquid Miracle grow to make phyto so I am sure you could use it to grow an algae screen. I dose phyto pretty heavy and it does not seem to affect my tanks or the scrubber but most of the fert is used up by the phyto by this time. I tried to support a Mandarin in a 10G but it was just not enough. I had another 10G with a scrubber so I put a bunch of like rock in it to grow pods. I swapped out a few rocks every week between the two every couple weeks and was able to maintain but this was with 20G combined and a lot of rock!!!!! so maybe with a larger tank like a 20L you could.
