How slow can I go?

[thejon]

Greetings all! Brace yourselves, I have too many questions to be healthy.

Currently have a 72G bowfront sitting with nothing in it (nothing alive anyway). Tank was down and dry for a couple of years; and I just recently refilled it with intentions of keeping a freshwater, pretty simple community tank. In testing where my cycle was, I remembered that before the tank was broken down last, I had switched over to some sort of cichlid sand. I'm about 85% certain it's "sahara sand" by carib sea (link) I thought it was buffering my pH up, to the range where I thought perhaps I may be able to just push this over to salt-water. So I started researching.

Turns out, it's actually buffering my ph down quite a bit. My tank tests right now about 7.9, my tap water is above what my test will measure. (apparently my local water is somewhere in the neighborhood of 9.8, per water quality reports. Obviously, there's no way I'm getting away with doing anything salt-water related without a minimum of an RO/DI system.

So, list of questions:

1: If I were to convert this tank to salt-water; can I keep my existing sand? Caribsea says it can be used in marine tanks, but I'm worried it will pull the pH too low, based on what I'm seeing now. Granted, the water in the tank has no salt-mix, so that may be a factor as well.

2. Sand bed is currently about 1 inch deep. Sufficient for FOWLR, or do I need to increase it? If I were to increase it, could I mix reef sand, or would I need to completely scrap the existing sand? (assuming I can keep existing in the first place)

3: Currently, my decor is a mix of resin / natural rock / driftwood. If I pulled the driftwood, could I slowly convert the tank over to live rock? Perhaps buy 20 lbs of dry rock and 10 lbs or live, then a few weeks later pull more resin features / natural rock and add another 10-20 dry rock, and so on until I hit about 80 lbs total? Perhaps add another 5ish lbs of live rock each purchase? The natural rock is, I believe, mostly river rock. I know it can't stay, but can it stay short term?

4: Going along with 3; if I have 10 lbs of live rock and another 10-20 dry, once my cycle is completed, can I add a few turbo snails and perhaps shrimp to give my tank something to look at while I build up the rock base?

5: Currently running a canister filter. I know I'll need to go to a sump system, but at what point does this become a requirement? Should this be in place before I add any cleaners, or before I add fish? Perhaps before I hit 50% of my expected bio load?

6: Skimmer; again, at what point does it become a requirement? I do not have the lighting, nor the budget, to move to a full reef system. If I'm keeping hardier fish; is the cleaning crew and live rock (plus the eventual sump system) enough, at perhaps 50% full load?

7: At what point in all of this can I add fish? Are they greatly bothered by the addition of new dry / live rock?

Thanks in advance all. Lots more questions to come I'm sure!

 

[Bifferwine]

Whew!! That's a lot of questions, so I'll try to start at the beginning! :D

1 and 2. I would use new sand. Even if it was sand for a saltwater tank, you do not want to reuse old sand. It contains crap and detritus and once the tank has water in it, that crap will just get released into the water over time, lowering your water quality. You should buy some aragonite sand (it doesn't have to be live, it can be dry sand) and a 1" to 2" depth is perfect. Generally, 1 lb of sand per gallon of tank size will get you within that range. Do not use play sand or sand from the hardware store. Those sands contain silica which will be a neverending fuel source for algae.

3. You should not use river rock or any sort of rock for freshwater. This rock tends to leach heavy metals into saltwater which can make it very difficult to keep animals alive, and leads to algae problems that cannot be fixed without removing the source (the bad rock). In the past month on this site, there have been at least two or three people that have been frustrated with their algae problems and it turned out they had used pieces of river rock in their tank. Saltwater tanks are based on the ocean. We are mimicing the natural environment of these fish and inverts. So we have to use rock that came from the ocean, not from rivers. You can buy dry base rock that is very affordable (usually about $1/lb) and fill your tank with that kind of rock. You will need to buy a few pieces of live rock to "seed" the dry rock and turn it "live" over time. But using driftwood and river rock should be out of the question for a saltwater tank.

4. Once you have a little rock, you can certainly add some livestock to your tank, then add more rock over time. You don't need to buy all the rock at once. You can add it gradually as your budget allows.

5 and 6. A sump is not a requirement. Canister filters are not helpful in saltwater (as you are probably finding out, there are very few things you can use for both freshwater and saltwater -- it's not as simple as just changing the type of water used in a tank). Sumps are definitely helpful and useful. But they are not required. The best type of filter you can get for a saltwater tank is a protein skimmer. They make hang-on-back models and in-sump models. Having one hanging on the back of the tank looks ugly, and having it in the sump keeps it out of view. But for a 72 gallon tank, I would definitely look into some sort of a skimmer. If you get a hang-on-back skimmer now, you can always move it into the sump down the road if you decide to set up a sump. You can run the tank without a skimmer, but that just means more water changes and bigger water changes.

7. You can add fish after your tank has cycled. Ammonia and nitrites should be at zero before you add any animals (snails, fish, crabs, etc.) Cycling usually takes 3 to 4 weeks in a typical tank. Fish are not bothered by the addition of new rock over time. When you do add fish, add one or two at a time, and leave 3 weeks or so in between each addition. In saltwater, a good rule of thumb for stocking limits is 1 fish per 10 gallons (vastly different than freshwater). So in a 72 gallon tank, figure on 7 or 8 fish total. When you research fish, make sure you look at their minimum tank size requirements. There are a lot of saltwater fish that look small but require a ton of swimming space.

 

[JohnVH]

Biffer has you covered very nice response

 

[thejon]

Thanks so much for the reply! Bummer about the sand; in all honesty, I initially didn't wash it before setting it up, counting on the crap in there already to seed my freshwater cycle (it's working, too). What is it that prevents this from happening in established tanks? The snails / shrimp / etc, I assume? What would prevent them from "fixing" it with the existing sand? Is it just a matter of too much build up for them to deal with? I'm sure I'm missing something, just no idea what :)

 

[Ted]

The major difference between saltwater/reef tanks and freshwater. You have to try to limit nutrients in the system. Nutrients in the form of phosphate, nitrate, silica fuel algae. Its a fine line because algae is the building block for coral life but at the same time it is the bane to a healthy tank. Symbiotic algae in corals and macro algae are good. Hair and bubble algae will take over a tank. Having "old" sand in a system will give you a huge amount of nutrients at the start which will fuel the bad types of algae. Mainly because the good bacterial died when the sand was dry. Just like taking sand from a fresh to a salt system the bacteria will die and the nutrients are still there. Also most freshwater sand and rock have silica. Those fuel diatoms which are just ugly and can cover and kill corals. Rock from the ocean already has the silica eaten away while in the ocean. Hope this helps.

I would recommend reading the bible for saltwater....The consciousness Aquarius by Robert Fenner. I have read that book cover to cover at least 20 times and still find things in it.

 

[thejon]

Thanks, that makes sense. To be sure I'm understanding, it's not the nitrate's that build up that's the problem, it's the nutrients from the FW bacteria die off and detritus that cause algae blooms? The cleaning crew inhabitants would take care of the nitrate packets (in that they'd be released), same as with new sand.

When you say "more and bigger water changes", what size / frequency are you talking? If I cycled the tank, put say 30% of my total rock in there, and added cleaning crew and a single or pair of fish... manageable? Or not worth the trouble?

 

[Smitty]

Welcome to the site...

 

[thejon]

Hoping I don't need to start a new thread for this; but when it comes to powerheads; can I get away with cheaper ones? I found a couple no-name brand ones on ebay for dirt cheap; but I worry they won't do the job. Also, with a 4 ft long tank, would two x 800 gph be enough? I know it's enough flow, but I'm worried it'll be too much in one area, and not enough in another. Would I be better served with 4 x 400 gph?

 

[Ted]

Most of us use Hydor Koralia because they are priced well and have a broad current. I got 2 Hydor Koralia Evolution on ebay for $25 each which is dirt cheap. I have multiple types of power heads laying around. The only ones in the tank now are the hydors because of the wide current. The others I use for moving water from bucket to tank, stirring salt mix..etc

 

[Bifferwine]

You want your turnover to be at least 20x the tank's volume. That's 1440 gph. So two 800 gph powerheads would be fine. You can go with cheap ones, but you will probably end up having to replace them sooner rather than later. I think two powerheads for a 72 gallon tank is fine.

 

[thejon]

Thanks all, really appreciate it. What is preferred here; asking questions in my existing thread, or starting a new thread for unrelated questions? I can see the merits of both (lower DB size for the site vs easier thread searching, for example), just want to fit in :)

 

[salt_for_brains]

New thread for unrelated question would get you better results, IMO.

 

[Bifferwine]

I agree. New thread for new questions. If you are following up on a topic you already posted about, you can keep it in one thread. More people will see your question and you'll get more input if you start new threads for different questions.