Do you guy's hate Undergravel Filters for Saltwater aquariums?

Question

Hi,

Getting some conflicting things said about undergravel filters.

Here's my setup and anyone thats tried it please post postive and negitive aspects of what im about to do.

This will be a 20gallon Saltwater Fish and 10 pounds of Fiji Liverock cured twice (no livesand) only aquarium. Dead Coral decoration 6inches by 6 inches. Dead Coral Sand Marine Substrate (this is more corase than sand, not sure why they call it sand) Instant ocean sea salt. 100 wat heater and regular tank Fluorescent hood.

Undergravel filter with 2 reverse Venturi powerheads 270gph each with flow control. A hang off the back powerfilter (400gph Skilter) with built in protien skimmer w/ 2 carbon filter carts and added room to add carbon / zeolite bags and additional bactiral growth medium. And ive set up the Skilter filter and the output of water can somewhat be adjusted.

I plan on putting in 2 or 3 tankraised clowns and a gobie, maby a cleaning shrip. (After 2 or 3 months)

Thanks for the tips

As you can see the items I have purchased are maby 2 to 3x's the amount I need for a 20gallon. I oversized my purchases so at a later date if im successfull with this small tank I can start a larger tank, maby a 55 gallon. Even though clearly a 55 would be much easyer on me to manage. Im hopeing I can do the 20.

Ive been considering making my own trickle filter to help with the bioload. I have tons of empty 10gallons and a 2 gallon and 5 gallon tanks I can chop up into a Trickle filter. But im sort of lost on what to do. Ive viewed some DIY Trickles on the internet but they really did not show step by step instructions that I could understand.

Call me dumb but does anyone know a easy inexpensive way to make a trickle filter? Like I said I got the tanks. Im not sure what kind of pump and tubing I would need. I can get a sump pump cheap but not sure if thats the kind I would need. And the bio material and plasic drip plates I can get cheap.
Im working with glass cept for 5g plasti

Hi,

No gravity feed. Was planning on making a overflow box. I made a new question about this on here under Home Depot Wet/Dry

Thanks for helping out. Im leaving this open a bit long for my initail question also.

Thanks again

Answer 1

I answered one of your previous questions today and brought up the undergravel filter there.

As far as an undergravel, people do use them in saltwater tanks, no denying that. Many have used them with success.

I don't use them (personal choice) and have had success without them. What I consider their major drawbacks are that with the size of the substrate used in some marine taks, the undergravel plates can have the substrate get stuck in the holes that are supposed to have the water pass through. Add any organic debris and you can get a fair sized area clogged or trapped beneath the filter where it's harder to remove with a siphon and the detritovores (snails, hermits, seastars) can't reach it, so as it sits there, your nitrates build. If enough of the filter plate and beneath gets clogged, anaerobic areas may form where hydrogen sulfide gas can build up. This is toxic to fish and other organisms in the tank.

That's why I said that if you use the undergravel, using the powerheads with the flow reversed as you'd planned was the way to go. By reversing the flow, you're blowing water down the tubes where it will blow any detritus upward to reduce clogging and trapped organic material to prevent the formation of hydrogen sulfide. But it will blow any dust from your substrate around as well.

I'll forewarn you about the Skilter here, too. I've bought two of these when they first came out with plans to use them on 10 gallon quarantine tanks. Both leaked terribly where the motor connects to the plastic filter body. I tried wrapping them silicon tape (used to prevent leaks) and after a few days, they started leaking again. Also, the efficiency of a skimmer is related to the amount of time that the water is in contact with the air bubbles. A good skimmer column should be the height of your tank or longer. A Skilter is maybe 1/3 to 1/2 the height of your tank (you didn't specify 20 standard or long). They will remove some of the organics, but for the price you pay for them, and their tendency to leak, I would rather spend a little more and get something that does a better job and keeps my floor dry.

Apart from that bad news, you appear to have a good set-up. As long as the substrate is under 4mm average size, this still fits in the range of sand - probably small or broken shell material to help buffer the pH in the tank. The heater is a good wattage for the tank (5 watts/gallon) unless where you're keeping it is more than 10 degrees below the tank temperature you want to maintain. And you've actually got more than enough filtration power (in gph).

For fish, I'd suggest just two clowns and buy them as juveniles. This way you'll be more likely to end up with a mated pair. A third would likely be rejected and harrassed by the other two once they pair up. Gobies and shrimp are fine additions and you might want to add a few snails and hermit crabs for cleaning. And you're more than likely going to get some other additions on the live rock.

I put a few websites below with more info on undergravel filters in marine tanks, showing both good and bad points of using them.

Good luck with your tank!

ADDITION: Good that you're planning ahead for an equipment upgrade. As far as the DIY trickle filter - here are some plans: http://www.sydneycichlid.com/content/?page_id=15 , http://www.thekrib.com/Filters/trickle-blackford.html

Don't know if you're planning to use this on the 20, or wait till you go up to a 55. Is your present tank drilled for gravity feed? If not you'll need a over-the-tank design, or risk cracking the glass if you try to drill. You might want to wait an a trickle filter until you buy the 55 - and buy one already predrilled.

Answer 2

Filters For Saltwater Aquariums

Answer 3

Installing one in an already established aquarium will be a bit difficult. You would have to empty the tank and put in the U.G. filter plate, then replace your gravel, decorations, etc., then refill the tank and lastly put the fish back in. If you do this you would want to save the water and re-use it and you do not want to clean your outside filter. We have always used both types of filters, a hang on power filter and an undergravel filter on our aquariums. The undergravel helps to pull waste down through the gravel and provides additional areas for the beneficial bacteria to develope. The downside is that you need to tear the aquarium completely apart to clean under the U.G. filter plate at least once a year. We would never recommend using an undergravel as the only filtration for any aquarium.

Answer 4

Your set up sounds ok. I do run an undergravel in one of my 30 gallon salt tanks but not on the larger ones. Honestly I like the UG's on smaller tanks when run in tandem with another filter. I have never had a problem with sand or crushed coral blocking the plates or getting sucked into the tubes and spit back out. Some will initially, however if you are running the filter pads on top of the plates there is no problem. The main reason I love the UG on smaller tanks is when feeding frozen brine shrimp, the UG pulls the debris to the bottom an doesn't give it time to cling to rocks and coral making the tank look messy. Easier clean up as well.

Your powerheads however should be turned down a bit. Flowing at 270 GPM is quite a powerfull draw especially with two. That is 540 GPM that is drawing your entire tank 27 times over per hour. Too high. Turn them down to turn your tank only 3-5 times per hour.they need cut back to around 50 or 60 each. Having such a draw will also not allow your live rock to feed. It will also reak havoc on your bottom feeders. Pollyps and inverts that could be inside the rock will starve. Kind of like living on a planet with 20 times the force of gravity.

Carbon isn't needed in your tank and you will find it will become saturated within a few hours pulling 400 gallons per hour. your filter should turn the tank volume 3-5 times per hour up to 7 is fine but you really don't want to turn the tank more than that. Yes there can be problems with OVER filtration. (As far as rate goes) The phosporus pads are gread however in the filter at this point to control the algae, until you decide if you want corals.

As far as building a trickle filter they really aren't that difficult and tygon tubeing is your best bet. (unless you are really getting into building the pipe work) Just remember the flow out needs to equal the return. I have plans somewhere I will have to find them and I will send them to you via email.

Answer 5

Your setup sounds alright.

And you're right, there's lots of debate over under gravel filters. Personally, I've never used one. It should be based on what type of substrate you have. Crushed coral would be alright to use, but sand wouldn't work because too much sand would be pulled into the filter.

This is kind of a small tank for saltwater. There may be large fluctuations in water conditions when cleaning and doing water changes. But if you're planning on fish only, this will be alright. Gobies are good for a small tank, as are chromis and other smaller fish. Clownfish may be too big after 2 years or so especially if you have 2-3. Cleaner shrimps are good and really fun to watch. Also, get some dwarf hermits to help with clean-up.

Answer 6

Absolutely massive overkill in my honest opinion. don't bother with additional bio filtration given the amount of rock, protein skimmer etc... carbon etc... you will have fantastic water quality. Nothing wrong with reverse flow for marine tanks.