This may be a weird question, and probably comes from my reptile based mind set in creating as close to a "natural environment" as possible. How detrimental is algae growth to a freshwater tank? I know it doesn't look nice, but it does feed on some of the nitrate right? Just a thought I have always had.
04-25-2012, 07:52 AM, (This post was last modified: 05-13-2012, 04:04 AM by Thor.)
The amount of nitrate being absorbed by algae is insignificant. The best way to remove nitrate is to do partial water change. We typically do 30~50% partial water change once a week to remove nitrate build up, as well as to restore water buffer, and minerals.
Everyone who had kept an aquarium for more than a few months would encounter algae more or less, whether they like it or not.
Algae feeds on mainly ammonia and nitrate, as well as phosphate, and some minerals too.
Excessive light is also another major reason, more so than the reasons above. It can be easily controlled by using an automatic timer to turn the lights on for only 8~12 hours.
In some natural environment, most places do not have overgrown algae as the water contain very little nitrogen based nutrients. You will not find any natural water with over 5ppm nitrate. Unless with human interferences such as leaking fertilizer into the water system, which can cause algae boom. In typical aquariums, nitrate concentration is usually between 20~40+ even with weekly partial water change, this number can be a whole lot higher in some less well maintained fish tanks. We usually aim for no more than 40 for the health of fish, because it is said that high nitrate can lower the immune system of fish.
In some natural places, you might find overgrown algae, but you should avoid it in a closed system like an aquarium. Although it is not that you can avoid it just because you want to.
Algae come in many forms. Some will grow on the surface areas only, some will make your water green, some will become hair like, some will create hard to remove green spots. I say avoid them at all cost.
I just asked, because the situation my aquarium is in, I don't do anything close to regular water changes. And there is a pretty good load of fish in there for how small it is. 2 large clown loaches, 6"+, a very large plecostomus. a yoyo loach and an angelicus botia, both around 4" or so. The tank is very well established and hasn't has a trace of ammonia or nitrite in over 5 years. Even if I go for 2 months with out doing a water change, the nitrate almost never goes over 40ppm, sometimes it is still even lower. There is a decent amount of algae, the plecostomus takes pretty good care of the glass, but in the corners, on the rocks, etc... I had always just wondered.
Nitrate build up over time if you feed very little. Most people feed more than the fish need, it is why nitrate builds up fast enough to require more than "once 2 months" partial water change. You must be feeding very carefully to achieve low nitrate concentration even 2 months without water change. Algae has nothing to do with it. I have a tank full of plants which absorb way more nitrate than algae will ever do, my nitrate will build up faster than your tank if I don't do water change frequently.
Water change is also for more than just to remove nitrate. The process of producing nitrate is acidic. Over time, the water buffer will be gone and the PH can crash suddenly. Fish don't like sudden change. Sudden crash of PH can cause problem, and can cause problem again when you finally do a water change which can restore the PH (suddenly) again.
There is also other dissolved waste other than nitrate. Fish are basically swimming in their own waste if you do not do partial water change regularly. It is not healthy for them in long term.
Oh, how long have you had that common plecostomus? When they are adult, they barely eat any algae at all. They produce a lot of ammonia.
He's been around about a year, maybe a little longer. I added him in to help out the algae problem since the tank is not in my house. I am not sure if he is a "common" pleco or not. He does do a pretty good job on the glass. It's clean, and I haven't actually cleaned or scraped the glass in almost a year. I'll have to get some pictures after I get everything switched over to the tank hear. They don't get over fed IMHO. Frozen brine, mysis, spirulina, bloodworms, etc... once a day about as much as they can knock down in less than 10 minutes. When I go over there I may spoil them a bit, but it's generally even keeled. I do a water change on average once every month. It varies though as it is not here. The PH does run acidic most of the time. Normally around 6ish.
Anyway, all this is why I need to get the fish moved and into a bigger tank, and here in the process.
Resist all attempts to overfeed. The fish don't know when to quit on eating in most cases. They can bloat and die from being too full. I wouldn't get pleco for algae cleaning, they are more like just a bottom feeder to eat what is at the bottom of the tank. Otocinclus Catfish are much better for this job of cleaning algae. Some shrimps are great too. Amano shrimps are the best from what I heard, but I have never kept any.
I highly recommend to do partial water change no less than once every two weeks. Once or twice a week is even better for the health of the fish. It is proven that they live longer and healthier with more frequent water change.
Frozen brine shrimp can easily spoil the water in my own experience. Once I dropped a cube frozen brine shrimp into my community tank and my fish finished it off quickly, I tested and detected ammonia in this well established tank the very next day.