Suggestions to optimize filter setup on new 55gal tank

[melonie]

Hi everyone. I'm in the process of setting up and cycling a new 55 gal tank. I just found this fantastic forum, and based on the posts I have seen here, if 'better ideas' can be found they'll definitely be found here. Since it's a lot easier to make filter changes before I put fish in the tank, I'm hoping you won't mind if I try to pick your collective brains.

Because I travel a lot, I wanted to set up a filter system which could operate without requiring 'major service' for at least a month at a time and would provide the best chance of avoiding potential water quality problems from getting started. I went with a Rainbow Lifeguard modular setup --> http://www.pentairaquatics.com/products/detail/quiet_one/Q1_images/ModSys+Q1sm.jpg

First I run a Mag-Drive 7 submersed in the tank. 1/2" hose and plumbing feeds a gate valve teed to a bypass valve. The first module is an AF-94 mechanical module with pleated filter. The output is connected to an AF-93 chemical module with about 8 ozs of carbon. From here the output is connected to a QL-8 sterilizer module with an 8 watt UV bulb. From here the output is connected to an AF-94 heater module with a 200w glass tube heater and also loaded with ceramic bio-balls. The output then goes through another gate valve and hose and dumps into the 'suction tube' hole of an el-cheapo AquaTech over the side filter with Rena 20u foam filter pads in place of the 'bio fiber' which came with the AquaTech.

I reversed the recommended order of the UV and heater modules, because I figured that the water is cleanest after leaving the carbon, and also that an 8 watt UV bulb also acts as an 8 watt heater thus putting the heater module at the end would provide a steadier temperature regardless of whether the UV bulb is off or on. I also like the idea of being able to run some kind of filter media before the water from the UV and bio-ball modules is dumped back in the tank, and the AquaTech allows me to add the Rena pads in whatever micron rating. I might try the 1u pads once I see how quickly the 20u pads load up - hopefully they won't load up at all just from dead bugs killed by the UV.

Using a bucket and stopwatch, the flow rate is just over 200gph without the AquaTech's pump running, despite a 700gph 'open hose' flow rating of the Mag-Drive 7 pump. Starting the AquaTech's pump as a 'booster' didn't make any noticeable difference, so I just left it unplugged. Figuring that 200gph on a 55 gal is a bit on the low side to handle big fish (like an Aro), and also figuring that the bio filtration of the modular setup will be pretty marginal, and most of all because they were on sale, I also added a Penguin 330 filter setup. At the moment the Penguin 330 does flow about 300gph running just the standard filter packs and bio-wheels. I thought that having a second filter would also come in handy if and when I have to open the bypass valve on the Lifeguard modular setup to slow the flow down to a trickle thus allowing the UV sterilizer a chance to 'zap' nasty bugs or parasites. Also at the moment two shrimp are decomposing in the Penguin 330's otherwise empty media baskets to jump-start the tank cycle.

As a side note. I also run a second 200w heater immersed in the tank.

I read through most of the posts in this forum and didn't see any references to the Rainbow Lifeguard equipment. I welcome all suggestions, comments, and criticism.

 

[mattrox]

How effective is it at the moment? Is your tank clean? Does debris build up ultra quickly?

Rather than the carbon, why not add something like biomax? More biological filtration. You might get a better water flow around the scintered glass noodles than carbon. Reserving the carbon for special duties??

 

[melonie]

The tank is pretty much crystal clear ... but it's still early yet ! I initially went with the carbon because of the 100% new tank setup and the fact that I have well water. You're right that I may not stick with this once things are stabilized and I'm only doing 20% water changes weekly. You're also right (very good idea) that I could dump the carbon and fill the 'chemical' cartridge with bio-max instead, and still have the option of adding carbon to the inside chamber of the paper filter cartridge if and when I ever need to 'clean house' in the future.

You may be onto something about the back pressure too ... but not so much because of the carbon. I've been doing some observing of the back pressure gage (no significant increase yet. But I've also been doing some research on pressure drops versus pipe/hose size. As a result I'm seriously considering replacing all of my 5/8" hose and 1/2" valves with 3/4" fittings instead. Doing this should reduce my 'head loss' by at least a couple of 'feet', which according to the mag 7 pump curve could potentially increase my flow rate by up to 50%. At the very least it would allow for significantly more filter 'loading' before the flow rate drops off to the point that a full cleaning is required.

 

[melonie]

also - I quickly discovered that I could switch to 1 micron Rena pads in my post-filter. Doing this REALLY cleared up the optical properties of my tank water. It's surprising how much gray-black 'slime' the 1 micron pads take out ! But thinking about your point re the carbon, much of the black stuff showing up in the 1 micron pads is probably the result of microscopic carbon powder escaping past my 'chemical' filter cartridge.

 

[mattrox]

I have never used or seen a filter like that, so I am only guessing..... But you seem to have a good grasp of what is happening and why.

I can only encourage experimantation so you can optimoze your system.... then tell all of us so we can copy too 8O

 

[melonie]

another update... I just finished replacing all of the 1/2" valves and 5/8" hose in my filter 'loop' with 3/4" hose, 3/4" full bore ball valves, and 3/4" fittings. The flow through the Rainbow Lifegard filter modules has now increased to more than 250gph, and the water level in my AquaTech post-filter increased to the same level that filter normally operates at when using its own built-in pump in a stand-alone mode. I never realized just how much of an effect that even 'minor' plumbing restrictions can have on overall pump and filter performance -after changing to all 3/4" plumbing the filter 'loop' flow rate is now exactly where it needs to be.

During the plumbing change I also discovered that one of my original 1/2" pipe fittings which was sold to me locally as supposedly being stainless steel was actually just plated steel ... and had already begun to corrode from the inside. All of my new 3/4" fittings are either PVC or Polypro, including the hose barbs, so now there's zero risk of metal leaching/corrosion causing potential problems with the tank water.

Going to 3/4" plumbing with my existing mag 7 pump was a much better and far less expensive option than increasing the pump size to a mag 9 but keeping my original plumbing would have been. My immersed mag 7 pump already occupies a good sized chunk of tank real estate and already generates a good bit of water heating - the physically larger and more powerful mag 9 pump would have aggravated both of these issues besides costing another $70 or so.

I also popped open the Rainbow Lifegard modules to check build-ups. The pleated paper filter in the 'mechanical' module had just a bit of discoloration and no build-up, so I rinsed it and put it back in service. The initial charge of activated carbon in the 'chemical' module had loaded up pretty good (and was also starting to create back pressure on the gage), so I opted to postpone a switch to bio-media for the future and put in another new carbon charge (I'm not sure what the carbon is grabbing, but it's obviously grabbing something - right now at least). The UV module showed just a tiny trace of build-up on the quartz tube which cleaned off immediately with one sponge wipe. The bio-balls in the heater module showed a small trace of surface 'slime' indicating that a bacteria colony is taking hold.

Up in the AquaTech post-filter the 1 u Rena filter pads have a bit more gray-black surface coating but weren't restricting flow so I left them in. If anything the super fine carbon powder which is escaping from the 'chemical' filter module but being grabbed by the the Rena 1 u filter pads seems to be improving their filtration ability based on the optical clarity of the tank water - probably by the same principle as a DE precoat with a sand filter. This unexpected development falls into the 'fortunate accident' category, but appears to be working great so far.

Water conditions appear pretty stable now that the cycle 'spike' has passed, and the Penguin filter's bio-wheels now have a noticeable bacteria colony going (as indicated by the color change), so after a 20% water change and putting in the fresh load of activated carbon I decided to stock up my new 55 gal tank - which now has four 4" tinfoil barbs, a couple of 4" Parrot fish, and a 4" black pleco. We'll see how things go from here on out with the filter system now having some significant 'load' to deal with.

I've got some zeolite standing by for the AquaTech post-filter's media baskets just in case the bio-filtering can't keep up with the abrupt increase in NH3 now generated, but hopefully the Penguin filter's bio-wheels will handle it just fine with no need for a temporary zeolite assist (opinion based on how well the bio-wheel has worked in my sometimes massively overstocked 6 gal isolation tank).

Even though running a submersible pump and separate filter modules is a bit more expensive way to go versus using a canister filter with built-in pump, and even though a submersible pump takes up a bit of tank space, to me it's worth every extra penny to never have to deal with canister filter priming problems or air burps or pump noise again (you can probably tell by now that I've wrestled with a Rena XP2 canister filter on a previous tank setup - that's where the 1 u filter pads came from). With the submerged mag 7 pump feeding the Rainbow Lifegard modules on this new setup, it's a tremendous pleasure to just hit the switch - the pump self-primes instantly, it force fills all the modules with tank water, it forces out all the trapped air in less than 60 seconds without any bleeding, and after that everything runs totally silent (well, providing my tank water level is maintained above the Penguin filter and AquaTech post-filter spillways anyhow, otherwise they splash). It's also very reassuring to know that when the power fails while I'm away from home that my filter system will definitely restart OK on its own once power comes back on.