New to discus, have a filtration question for a 75 gallon...

[20 20]

First, hello!

Second, the question isn't for me, but for my boy. I've got a 125 gallon African cichlid tank, and 20 gallon cichlid 'fry' tank, and a 29 gallon salt water reef tank. My boy (15 years old) has been keeping piranha for about a year now, and has just switched his 75 gallon tank to a discus tank. His current setup:

75 gallon tank, running an XP3 and an XP2. The XP2 is brand new, but the XP3 was running on a pirhana tank for 6 months. The tank was set up initially on Saturday (5 days ago) with just with thenew XP2 running. Sunday (4 days ago) we purchased 7 discus. Brought the discus home, drip acclimated them for 3 hours, moved the 'seeded' XP3 to the discus tank, put the discus in, and added a gallon pouch of Bio-Spira.

So far so good. He's got a large trash can next to the tank for aging water for changes. He's using a 25%/75% mix of ro/di water and tap water, and buffering to 6.4 PH before adding to the tank. Temp will match the tank, 85 degrees. He did the first water change Tuesday evening. A couple of hours after the water change the tank went through a bacteria bloom (the white cloudy water), but that cleared up by the morning, fish are doing fine.

So, that's the current setup. Sorry for the rambling. Anyway, now the question (finally). Filtration is currently the XP2 and the XP3. Seems like a lot of flow for the discus, however. Large side surface area, etc. Them swimming in the tank reminds me of driving my wifes minivan in a strong wind. Would running the XP3 alone be enough filtration on this tank, assuming the water changes continue to be done every other day? Taking the XP2 off would lessen the flow considerably, but is it necessary for mechanical/biological filtration?

Oh, and if you made it all the way through my verbosity, thanks!

[20 20]

Anyone?

[goldenpigeon]

ok sounds like you have it going ok, i am not familiar with these "XP2's and XP3's" what are they? canister, sponge filter, wet and dry?

basically with discus you want to turn the water over at least 3 times an hour. up to around 7 times an hour i recommend. if the discus are looking stressed and showing stress bars and being blown around remove one of the filters.

what is in the tank? substrate, plants, rocks, driftwood....???? how much light is on the tank?

HTH

cheers
David

[FishLover]

You may want to add a spread bar to less the current a bit. Discus don't like strong current.

[G-1000]

I would go with the spray bar suggestion or maybe just drill a lot of holes in the in tube. So that water flow is in all directions and reduces the current.

G

[20 20]

Thanks for the replies! It's a completely bare tank. Bare bottom, no rocks, driftwood, or plants. My boy has done a bunch of reading, and from what he's found he feels that the best way to care for the young discus he's got, at least until they get bigger. They are from 2 to 3.5 inchs. XP2 and XP3 are canister filters, EXCELLENT value:

http://www.thatpetplace.com/Products.../Itemdy00.aspx

http://www.thatpetplace.com/Products.../Itemdy00.aspx


The XP2 is rated at 300 gph, the XP3 at 350. So 650 gph between the two of them. In real life (with filter media in the canister) probably around 500 gph. That makes a turnover rate approximately 6 to 7 times (75 gallon tank). He's already using spraybars on both of the returns. The discus seem to be doing ok, but was just wondering what type of and how much filtration is recommended for discus. Seems like we're on the high side, but still in the turnover rate 'range'.

[Merrilyn]

Hello 20 20 and welcome to the forum. I congratuate your son on his choice of fish. Discus are certainly the 'king of the aquarium' and are the most beautiful and intelligent of all the cichlids.

You're obviously quite experienced with fish keeping, so I won't go into a lot of detail. You've done everything right so far, but I'm a bit concerned about the amount of water flow going through those filters. Discus come from still waters, with very slight current. Strong water flow (even through spray bars) will distress them. They are simply not built to be swimming against the current day and night. They like to 'hang' in the water.

My suggestion would be to remove the smaller of the two filters, and just run the XP3 alone. If you make the holes in the spray bar larger, and direct the outflow across the surface of the water, that will lessen the turbulance considerably. Even with that, I'd still be running an airstone in the tank. I run them in every tank I have. Warm water holds less oxygen, and discus have high oxygen requirements. The airstone is just added insurance.

Whilst filtration is important in a discus tank, your frequent water changes are the most important factor in keeping healthy discus. I do daily water changes on every discus tank, and young fry get a water change twice a day.

I agree with you son and the bare bottom tank theory, but I would add a couple of plastic plants to the tank, to give the youngsters a form of security. It's not absolutely essential, but I find it makes the youngsters bolder if they feel they have some hiding places to retreat to if some imagined danger presents itself.

Good luck, and welcome to the wonderful world of discus. We'd love to see some photos of your fish when you have the time. :P

[FishLover]

What I do is aiming the spray bar slightly up toward the water surface. I also drill more holes in the bar to less the force of water coming out of the bar. Make sure the bar is under the water surface. You should be able to see the water movement at the surface but the water is not shooting into the air. That will create oxygen exchange at the surface and slow down the current. I don't need the airstone in that case because the spray bar is doing the exactly the same function as the airstone. Kill two birds with one stone

[20 20]

Thanks for the replies! My boy has taken out the XP2 (gonna sell it to me!), and put in a few plastic plants and a couple of pieces of driftwood. Hopefully those changes will make the discus more 'at ease'.