questions about my tanks

Question
I have a couple of questions about stocking and such....

okay, so i have a 10 gallon aquarium. it is running a
hydrosponge 1 with an airstone in it and a 8 inch bubble stone along the back wall. there are 3 smallish plastic plants. i have 3 zebra danios, 2 glofish, and a black tetra in the tank. should i get a new filter or will the sponge be enough, i was told it only has a turnover of about 2 gph. if this is the case i can move it to the other tank and buy a new filter.

the other tank is a 14 gallon and has 2 goldfish in it, common and a fantail. it is running a 5 to 15 over the top filter (common walmart forgot the brand name) positioned at the left and has an airstone on the right side. there are 2 med=large plastic plants in it and 2 small-medium plastic plants. is this sufficient filtration/aeration for the fish? should i move the hydrosponge in for added filtration?

also i increased bulb wattage from 10 watt compact fluorescent to 15 watt incandescent to get rid of brown algae i have been fighting, and turning the lights off after 8 to 10 hours. would the 10 watt be better than the 15 if i can limit the lighting? the 10 watt lights the tank up so much better than the 15, even though it is less wattage.

thank you in advance for your reply, i look forward to your answers.  

Answer
Hi Angel,

Most people use sponge filters as additional filtration, using the sponge filter as backup in case they have to jump start another tank with bacteria or cycle a quarantine/hospital tank. They are not really intended to be the sole form of filtration, except in specialized setups such as fry rearing tanks. This could work perhaps with a highly oversized sponge filter but yours is not...2 gph is certainly not enough flow. You're striving for 4-6 times turnover with community tropicals, so you need at least 40 or 60 gph on your 10 gallon.

People do keep zebra danios in 10 gallon tanks, but they'e too active for a 20" tank, so they won't be at their best even if they are the right size for a 10 gallon. I recommend 20 gallon tanks, preferably the "20 long" which is 30" long. That black tetra is a schooling species, if you got a bigger tank you could provide it a few friends.

You are underfiltered in your goldfish tank. Messy fish like cichlids, puffers and goldfish need 6 to 10 times turnover so 84 gph to 140 gph. Also, your tank is too small for two goldfish, two goldfish ought to have a 29 gallon tank but a 20 gallon tank is minimum. You probably got one of those startup kits from Walmart, I see they have 14 gallon sizes now - really is much better than a 10 gallon start up kit, more possibilities. You should have two of those Aqua-Tech filters you have on there on your goldfish tank. Putting the sponge filter on the goldfish tank isn't going to do much, you certainly can do it, but it will get dirty really fast. I bet your goldfish are small now, but just wait until they get big and start pooping like crazy! What you feed them makes a big difference, I'll explain in a minute.

Your goldfish would really appreciate some additional aeration, well aerated water high in dissolved oxygen suits them well - they are cold water fish and the cooler the water, the higher the oxygen level. A bubble wall powered by an air pump would be ideal here.

These are three articles I recommend to anyone keeping goldfish:
http://www.wetwebmedia.com/FWSubWebIndex/goldfish101art.htm
http://www.kokosgoldfish.com/food.html
http://wetwebmedia.com/FWSubWebIndex/gldfshmalnut.htm
Even if you do not read them now, bookmark those links.

I would not use those 15 watt incandescent bulbs. First because they are not very attractive, second they put out lots of heat which the goldfish don't like, and third they burn out fast. Go back to using the compact fluorescent bulbs - those 10 watt bulbs from Walmart are designed to be about as bright as 40 watts each, I believe - since they are not the cause of your algae. I'll tell you what is.

Algae needs two things to thrive: light and nutrients. You have overstocked and are possibly overfeeding your 14 gallon tank. Even if you are feeding reasonable amounts of food, goldfish flakes and goldfish pellets are very polluting compared to say, vegetables. Even if the food is all gone and none of it is falling to the bottom, the algae can still use the poop from the goldfish as food.

If you got a pleco - and certainly if you asked, this is what Walmart would say to do - he would eat the algae but produce tons of waste, they poop even more than goldfish, and they get huge! I've had plecos outgrow 75 gallon tanks. I heartily recommend you DO NOT get one.

Read this article about algae to understand better:
http://www.thetropicaltank.co.uk/algae.htm

Brown algae is common in new tanks, but if your water is hard, it is more likely to have brown algae permanently. The best way to combat it is to get live plants and bright lights. This will take some investment since regular aquarium lights from Walmart will NOT grow live plants, they might survive but they won't thrive, and thriving fast growing plants are what combat algae.

To fight your algae naturally, you should do two weekly water changes of 30-40%, always adding dechlorinator that removes chlorine and chloramine. Feed 50% vegetables, 25% frozen foods and 25% dried foods which is the ideal goldfish diet - dried foods only diets are bad for your fish and your tank. They constipate your fish and/or cause buoyancy issues, also they dirty your tank. To put it crudely, poop that is made primarily of vegetable matter is not going to feed algae the way poop that is made primarily of fish meal is. Plain and simple. Feeding less and feeding the right foods, and changing plenty of water a week...this will take care of your algae problem. Chemicals such as Algae Fix, chemical media such as Algone and other such "quick fixes" are nothing but that - they may work, but you have to keep replacing them on a very regular basis. Besides, they treat symptoms only.

To really succeed at fishkeeping and to grow in the hobby, it is really necessary to read a whole bunch. These websites are a fine place to start, bookmark them and turn to them first:
http://freshaquarium.about.com
http://www.wetwebmedia.com
http://www.kokosgoldfish.com

If you are an adept searcher and know how to separate the bad information from the good, you may never need anything more than Google to find the answers you need. Think twice before you take the advice of someone working at a chain pet store, Walmart, or someone from a forum that doesn't sound knowledgeable. There's tremendous help to be had from online forums but there's tremendous bunk out there, as well...so use your best judgment, and when all else fails, get an aquarium book. There are tons of freshwater aquarium books out there, at bookstores, on Amazon.com and at public libraries. Books are "one stop shopping" sources for information!

Best of luck, keep reading is all I can say. If you're willing to educate yourself about fishkeeping, especially essential concepts like the nitrogen cycle, biological media, water quality and chemistry and nutrition, researching the needs of every fish you get before you buy it...you're practically guaranteed to be be successful!

Nicole