Cleaning a Friend's Tank

[Madam Macaw]

My BFF's hubbie recently broke his leg and had to have surgery. He jokingly asked if I could clean his tank. His tank is 75 gallons, has one gigantic fish - will have to ask him what, and a few tetras. That is it. Everything is the tank is covered in a dark green algae. He has had this tank for a number of years, but I was wondering how would you clean a tank in this condition. He keeps the light on 24 hours, etc. I told him you should only keep it on for 10-12 hours at the most. Again, he has had this tank and fish for years, while I am relatively new at this though I have done a ton of research - I kinda feel like a heel telling him what he is doing wrong.

So, first things first - how would I clean the tank, gravel, etc - the tank itself looks clear, just dark green on everything in it except for the fish. I wouldn't want to overclean it and have the tank re-cycle.

In looking at the archives, I think peroxide would be a safe way to go, but how much of the gravel is safe to do. Assuming you would do it in increments.

[trashion]

I got this question a couple of times when I worked at Petco. This one woman, her father had fallen ill, and his tank was in bad shape. SHe said there was even algae on the fish O_o.

I would turn this into a monthlong event, as I doubt that he does waterchanges too often either. Overcleaning would REALLY shock the fish.

Week 1: Buy a TIMER for his lights. Set them to go off after 10 hours. Scrub down the walls and soak maybe half of the decor in weak bleach solution. Do a 25% WC. Make sure to soak the decor in water with a ton of dechlorinator after bleach.

Week 2: Soak the other half of the decor, take out 1/3 gravel, do a 25% WC. Soak the gravel. Put it back in.

Week 3: Soak another third of the gravel. Put it back in. Do 25% WC.

Week 4: Soak the last of the gravel. you know the drill from here on.

Obviously, you don't need to follow this to a T, but just do things gradually, and in increments.

[Madam Macaw]

Will peroxide work as good as the bleach? I am a little hesitant with the bleach since it really isn't my tank and would be afraid of not rinsing it enough.

Thanks for the quick response!

[COM]

The tank doesn't sound good to me but I wouldn't do anything to it without asking him first. If he has had it running this way for years, he may want it that way and obviously the fish are doing fine.

I went to a school from third to fifth grade that had a very big fish tank in a wall between the main entrance and the cafeteria. I don't remember the exact dimensions but we're talking well over 1000 gallons. There were some goldfish in there that had allegedly been placed for the school's opening in 1971 so they I guess they would have been 20 years old or so at the time. The tank had been neglected for a very long time and there was a thick coat of green algae on everything. You couldn't see into it from one side.

My cello teacher, the man who initially got me interested in fish keeping, decided that he was going to do something about this tank. He started a little fish club. I joined with some other kids who quickly lost interest. Another teacher's husband owned a pet store nearby and donated two common plecos and two chinese algae eaters. We put them in the tank and let them be. Within a few months the algae was down to a reasonable amount everywhere but on the gravel. I think the cello teacher used a shop vac to get rid of most of the gravel and then we replaced it with white sand.

Then the cello teacher found another big fish tank in the school. It was a round column set up in the middle of a seldom used faculty lounge and it was also in terrible condition. The plecos and CAEs did a good job on that tank and as far as I know stayed there.

I share the story to demonstrate that you can actually use the algae eating fish to clean the tank. They won't do it very quickly so it shouldn't disturb too much else. And yes, the plecos do produce a lot of waste but if the tank is full of algae I wouldn't think that would be any worse.

[Madam Macaw]

I think I will sit down and ask him exactly how he cleans it. I know he doesn't do it every week like I clean mine. I couldn't get over how clear the water actually is - it is just on the gravel and decor.

[chattafish]

If you go with the adding a pleco, remember commons stop eating algae at a mature size. research a bristle-nose. be sure to do a 50% water change the week before, and to only rinse the filter medium in used tank water that week. (If the water is mucky, use declorinated water.) The second week you can add fresh filter medium, with only a 20-30% water change.Trashion's right- if you go the manuel/chemical route, go slow, and test anything soaked in bleach/peroixode before using it back in a tank (no matter how many times you rinse.. (24h in fresh water/ test )

[Good Wolf]

I've seen several tanks that look great and the owners don't do a thing to them except top it off when it gets low.

It is almost a bit frustrating to see because I spend so much time maintaining mine. I can only assume that the fish are healthier with me doing this and it isn't a complete waste of time.

As already stated I would run anything you do by him first. I would be afraid of putting he fish into shock by doing too much cleaning at once.

[Madam Macaw]

Yeah, that is what I was curious about - how much to do without causing too much stress on them.

[emc7]

If you own test kits, test the pH, hardness and nitrate sbefore you do anything. I wouldn't change more than 10% the first time if you don't know how far the water is from new water. I also would avoid attacking the algae first thing, including reducing the lights. Algae may be the only thing keeping the nitrates in check. A timer is a good idea, but you should shorten the light period gradually.

If you find it does need a complete cleaning, make sure you have another tank for the "big fish" to visit (fill with his tank's water) while you do it. Then you can gravelwash, clean off the algae and do a 100% water change. Then you have to slowly acclimate the big fish to the new water.

[trashion]

emc7: that will just shock the fish and cause undue stress. You never need to do a 100% WC.

[COM]

I wouldn't do a 100% water change in a clearly established tank.

I would do a 100% decor change but not all at once. I would remove decor including gravel in maybe 1/3 increments each week and put in new stuff.

[emc7]

You never need to do a 100% WC.

If a tank has been neglected for over a year, the nitrates may be so high that anything less that 100% will still leave nitrates off the scale. Thats why I said to take the fish out and acclimate them slowly when you put them back in. This is a worst case scenario, but I'm assuming you wouldn't want to stay there and change water daily in increasing %s for 2 or more weeks, which is what you'd need to do to replace truly horrid water while the fish are in it.

[pokefan]

Do you have pictures of this tank? I'd like to see just how bad it really is...

[fishbguy]

The best way to do it IMO, would be to remove the gravel in 1/3 incraments as was stated, while doing weekly 10-20% water changes. When the gravel comes out, bleach it. I use bleach on decor and gravel a few times, and I've never had a problem. Just rinse it REALLY well. you can smell when the bleach is gone.

Do not put gravel back into the tank until it is all out and clean. IME, if you take some gravel out, then put it back in with old gravel, the dirt spreads, and the next week, it doesn't even look like you did anything with the clean stuff. If you take gravel out, without replacing it, in incraments, you'll be fine. I've taken all of the gravel out of my 10 gallon before at one time, and didn't have a problem.

The only thing I would be worried about, is getting the fish used to clean water again. But that is why you do weekly 10-20% waterchanges. 15 would prolly do it.

[Good Wolf]

I would be a bit concerned about anaerobic bacteria. If there are pockets in the gravel that haven't been exposed to oxygen then once released the bacteria could nuke the tank. I would think the odds of there not being some in the gravel bad are slim to none based on the lack of maintenance.

Please correct me if I'm wrong, but that is what I've been told/found online.

[pokefan]

Chris, I'm pretty sure that you won't have that worry with gravel it's just to easy for the gas to escape. Your problem comes with sand, it packs down much much tighter allowing the gases to stay trap underneath. I'm just as new as you though so I could be wrong as well! lol

[Good Wolf]

Arg! I figured it would be the other way around. Now I'm scared.

[COM]

Gravel is cheap. Why mess with bleaching it? Plus, over time it discolors. Just get new gravel and save yourself the hassle of bleaching it, rinsing, dechlor.

Plus dirty gravel stinks. Literally.

[Obsidian]

You could change the gravel by slowly removing it until about half of the gravel is gone. Then you could have a barrier to separate the new gravel from the old gravel. Then put the new gravel in on one half. After about 2 weeks you should be able to start removing the gravel from the other side as the biofilter would be established in the new gravel. When all the other half gravel is out you can put gravel in the rest of the new gravel. You could also slowly move the barrier and add new gravel as you remove old gravel. Thats how I would do it if I were to change gravel in a tank as neglected as that one.

I would not change more than 20% of the water at a time. I would only do one side of width sides of the tank for the algae, then half of the front or back, then the other half etc. So there is no nitrate spike and give the biofilter a chance to catch up.

I would also make sure he wants his tank changed.

Thats just my opinion.

[emc7]

You don't have to bleach gravel unless you are trying to remove dye or eradicate a disease. If its just dirty, tank it out by the bowlful and rinse it in the sink in a colander, disk dryer or strainer. Remember to dose the tank with dechlor when you put it back.

Question: is there a UGF in the tank? with a UGF the gravel is part of the filtration, so rinsing it can cause a mini-cycle. Without a UGF the dreaded anaerobic pocket are a small but real risk.