Setting up a reef - some advice please

[Rumpy Pumpy]

Hello again.

I have more or less, kind of, probably, decided to take the plunge and convert my freshwater set-up to marine and set it up as a reef.

The 4 ft tank is around 200 litres, has a 50 litre sump and an Eheim pump which currently shifts around 3500 litres per hour (it's rated 5000 litres, but the head reduces this somewhat I guess). The tank currently has one overflow located in one corner. Filtration is currently a filter sock on the inflow to the sump, 2 litres of Denitrate (crushed graded pumice) in a canister filter and some Purigen (as described on another thread).

I gather, from this forum, that it is possible (in fact beneficial) to run without a skimmer as long as a a good powerful algae scrubber is in operation. To that end I am proposing to do away with the sump and use the space to replace it with a large scrubber (which I will build myself). That should be no problem, plans and technical stuff are will documented on this forum so there's plenty of information there.

However, I do have some questions regarding switching to marine and reef keeping in general;

1) Will one overflow be enough? Or should I add another on the other corner.

2) With a powerful scrubber, would I need to do many water changes? What sort of w/c regime (I'm looking to keep a mixture of corals, inverts and fish and while I won't overstock I do want to keep a decent variety and number of critters). Will a RO system be absolutely necessary or will I be able to get away with dechlorinated tapwater or captured rainwater or buy the occasional batch of RO water from a LFS?

3) Could I continue with the Denitrate canister filter? It has been effective in reducing NO3 in my FW setup but not eliminating it altogether. Would retaining it interfere with the operation of a scrubber? Likewise the Purigen, which I'm particularly impressed with.

4) Live rock - if using an effective algae scrubber, do I need it at all? And if so, how much? LFS's seem to be intent on selling as much of it as possible and it ain't cheap. Can I get away with using some "dead" rocks of some description to house corals instead? And if so, are there any to look for or avoid?

5) Substrate - Lots? Little? What type? Does it matter?

6) Position of tank and natural light. I understand that some corals like a lot of light. Currently my tank is located where it gets quite a lot of natural light. Is this likely to be a good or bad thing in a reef tank?

Any other tips or advice would be welcome.

Many thanks and best regards.

[SantaMonica]

1) One overflow is enough. Really does not matter how fast water goes to the sump.

2) If the purpose of the WC is to reduce Nitrate, Phosphate, or nuisance algae, then you will not need to do WC anymore. If the purpose of the WC is to do anything else (like remove medications, etc), then you will still need to do them. So, if you dose Cal, Alk and maybe Mag (like I do) , then there is no other reason to do WC's. As for tap:

A scrubber does remove most of the "bad" things in tap water, but it is not known yet if they are ALL removed. And what certainly is not known is if they are removed fast enough for you to put tap water right into your tank. Chlorine is definitely NOT removed by scrubbers, but chlorine will evaporate in a day or so if the water is circulated in an open container BEFORE puting it in the tank. Chloramines (chlorine + ammonia), however, are another matter. They are added by some city water systems, and they are not removed by scrubbers (and they do not evaporate). So if you are not using RO or RODI water, you must use an additive to remove chloramines (if your city water has chloramines; ask them). Water from a well should be fine, since no chlorine or chloramines are added.

Some people are experimenting with using tap water instead of RO or RODI, but there are no results yet. A fish-only (no rock, no sand) tank is probably fine, if you have no chloramines, and if you let the water circulate for a day before using it (to remove chlorine). If you have chloramines, you can use an additive to remove the chlorine and chloramines right away, without having to wait a day.

If you have live rock, or live sand, or any corals or inverts at all, then your problem becomes copper. Copper can occur in city water or in wells. Yes a scrubber (i.e., algae) consumes copper, but the question is, will the copper be removed fast enough so that no damage occurs when you add the tap water. Nobody has tested this, so it would be an experiment. For best chances, you'd want an oversize scrubber, with powerful lighting, and strong flow, along with cleaning every 7 days no matter what. The best way would be to start with an new tank, and add your corals or inverts one at a time (cheapest first). This would be a good test for someone to try.

As for rainwater, I don't know.

3) Don't need or want any canister; will just clog up on waste. No socks or anything else either.

4) If you want to see how little LR you can get away with, just start out with a strong scrubber, and add livestock slowly, one at a time per week. If livestock dies, it's probably from ammonia, which tells you that you need more LR because your scrubber is not big enough. The recommended sizes of scrubbers were meant to be used with LR, not without. Some fish breeders want to have high loads, and no LR, and for them I recommend a scrubber 3X as powerful. Yours should probably be 2X more powerful than recommended.

5) No recommendation. Better resources on other sites.

6) Better resources on other sites.

[Rumpy Pumpy]

Many thanks SM.